Temperature

My 2000 C2 temp runs to the right of the zero in the 180 when the outside temp is above 80. See photo below. The radiators are clear. Is this within the 'Normal' range?

No. Something is wrong. Fans, thermostat or water pump may not be working right. Check the fans first.

Fans come on and no leaks from water pump.

My fans come on about when the needle is shading the right side of the zero. No idea if you have an issue or if this is another case of the temp gauge being inaccurate. Have you used the climate control diagnostic to check the coolant temp? I can't remember the button sequence but I'm sure it's posted in here somewhere.

My mk2 c2 runs hotter on the OBDII than the dash gauge. Normal spirited driving in mountains gives me 210-221F coolant temps on the OEM sensor. I'd check that with a scanner before spending money on changing things.

I checked the climate control temp and the car is running about 108c and 110c. Should u worry?

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Based on my experience with my Boxster 108C to 110C (226F to 230F) is about the max temperature the coolant ever got when driving in extremely hot ambient temperature (116F) or when driving the car in a spirited fashion -- if you know what I mean and I think you do -- in milder -- but still warm (mid 90's) ambient temperature. In the 116F heat the coolant temperature stayed at 226F or so until I drove out of the extreme heat which took a while. I was in southern AZ at the time and I don't think it got "cool" until I was in Oklahoma. When driving the car in a spirited fashion afterwards the coolant temperature dropped as I sat and let the engine idle. I was monitoring the coolant temperature with an OBD2 code reader/data viewer. The radiator fans were of course running at high speed. (With my Boxster they switch on to low speed at a coolant temperature of 212F and switch to high speed at coolant temperature of 216F and switch off when the coolant temperature drops to 205F.) In the case of your car, as long as the temperature doesn't get any higher you should be pardon the expression be cool. This assumes too the system is pressure tight and the system doesn't lose fluid. Might mention when the coolant is hot and the engine is shut off the heat load of the engine can raise the coolant temperature even higher and with it the pressure in the system. If there is a weak component -- in my experience a coolant cap and another time a coolant tank -- this component can leak. You should check that both radiator fans are running and *be sure* both are blowing the same amount of hot air out where the hot radiator air leaves the car. With my 996 Turbo one time while the motor was running the air wasn't blowing and it turned out to be a broken radiator fan motor shaft. Another time the passenger radiator fan motor of my Boxster wasn't even running and it was found to be the ballast resistor. The techs tell me the passenger side ballast resistor takes a beating if the car is driven in bad weather as the passenger side tires often splash through standing water along side the side of the road and this water can damage the resistor. While the resistor should be mounted in a pretty protected spot it can still get splashed if the water is deep enough. Yet another time -- and this is why you want to verify both fans are not only running but blowing the same amount of hot air -- again with my Turbo the driver side fan was running but it wasn't blowing nearly as much air as the other side. The tech connected the diagnostics computer to the car and found there were no fan stage errors but the driver side radiator fan motor was drawing way more current than the other side. I had him replace the fan motor. Afterwards both fans blew the same amount of hot air and current consumption was the same. Might add that even though with both of my cars one fan either wasn't running or wasn't running right the coolant temperature remained reasonable. One working radiator fan is enough to keep the coolant temperature under control but of course I would not push my luck and continue to drive the car -- other than to the nearest repair shop -- with a non-functioning radiator fan motor or fan. My concern would be if the other fan should quit then the engine could overheat. With my Turbo I found the passenger fan not running in Fresno. Instead of continuing east into one of the hottest regions of CA (ignoring Death Valley) and beyond into AZ where it is even hotter I turned the car back west and drove it the couple of hundred miles home and had it at the dealer the next day to have the radiator fan problem sorted.

This pump wasn't leaking. Have you cleaned between the aircon evap and radiators?

Thanks all...due to some of the issues these motors can have and the cost to rebuild / replace a damaged motor, I will take it in to my local indy shop next week. Better save than sorry!

With airco on both radioator fans (left/right) should always be on at "low" speed. Or with airco off, those fans come on at 104C and switch off at 100C again. Looks like your fans only come on in high speed, which they'd do at 107C (225F) and switch off at 104C (219F). Are both fans running (left and right)? You can check easily by sticking your hand under the bumper in front of the wheels. On mine one did not run at low speed and with that cooling capacity was much reduced. Volkert

My '99 will run here as well. Replaced the WP and thermostat, upgraded the cap, cleaned rads, and checked fan operation. I haven't gotten in above the line yet and that's the point I've decided to shut the car off. At highway speeds, temp comes down to the left side of the 0. My obd says this temp is 220F, lower than the dash readout.

Mine will run that hot in stop and go traffic when outside temps are 90 and above. Will come back down to the left of the "0" when moving again but it does seem to take forever to come down. I don't think you have an issue.

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Scary water pump!

I had been told the radiators were clean by the shop that did some paint touch up work. I decided to double check. It turns out that my radiators need to be cleaned. Does anyone have pictures for the 996 radiator fans hack: https://rennlist.com/forums/996-foru...tment-fan.html ? https://rennlist.com/forums/996-foru...tment-fan.html

Update: Cleaned the radiators and made sure the fans were working. Reassembled the car and went for a 30 minute spirited drive. According console computer, the car ran 100c-102c. In stop and go traffic it did get up to 104c but then cooled down to 102c. Pulling into my driveway the temp reached 105 and I didnt wait to see if it would cool down or continue to rise. Is this normal or is it still running too hot? Thoughts? Suggestions?

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That still seems hot, there are a couple of ways your engine could be running too warm. (assuming your water pump doesn't have impeller damage) One is the thermostat is not opening correctly allowing cooler liquid to be exchanged in the circulating engine path. Two is the cooling system is not dumping enough energy out to air to allow the thermostat access to cool enough liquid to pass through the thermostat. It might be useful if you could take a temp reading of the coolant lines going to/from the engine to the radiators, maybe with one of those IR temp gun things, they are cheap at Harbor Freight, that would tell you if you coolant system is dumping enough heat out of the radiator path. Pulling the thermostat and testing it in hot water is more hassle and at that point might as well put a new water pump and thermostat on while you have it apart.

I would look for about 10 to 12 degree's F drop between the inlet and outlet of the radiator with fans on, and normal load on the dyno.

I think your car is running hot at 104 C - 220 F. My temperature gauge does not go that far to the right even when hot on a hot day.

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And what was the outside temperature? What does it mean "the fans were working"? With AC on the fans should both run at low speed (that still is a lot of air blown away!!) all the time. If the temperature goes to 107C they should go to highspeed and cool down to 104C. With the normal thermostat it will only be fully open at 99C. So 100-102C is not strange IMHO when driving spiritly..

And what was the outside temperature? What does it mean "the fans were working"? With AC on the fans should both run at low speed (that still is a lot of air blown away!!) all the time. If the temperature goes to 107C they should go to highspeed and cool down to 104C. With the normal thermostat it will only be fully open at 99C. So 100-102C is not strange IMHO when driving spiritly.. Thank you all for the responses. A little more detail: After cleaning took the car for a drive. The outside temp was about 78-80F. The car warmed up slowly to the 180F mark on the analogue gauge after 10 minutes of driving. At this point I used the center HVAC hack to get a digital readout. The temp stayed around 99C to 100C for about 10 minutes. During this time I was traveling between 45-60MPH. Climbed a few hills and took a couple of fast corners The last 10 minutes of the drive was in slower traffic. Not stop and go but under 35 mph. The temp climbed to slowly to 104C. When I pulled in my garage the temp read 105C. The AC was on the whole drive so I do not know if the fans were running (I check to make sure both were running) at low or high speed. As a side note, my Indy shop did a coolant flush earlier in the year. I did not notice any temp difference after the flush. The coolant level in the reservoir tank is at spec at start up and after driving. My next step, I think, is it put a cooler thermostat (and water pump while I have it torn down) in. Thinking about this one: http://www.pelicanparts.com/cgi-bin/...20and%20Gasket Other suggestions?

I still don't think you have a problem. During regular driving the car runs around 180 but gets a little hotter with spirited driving uphill in warm weather. Mine does the same thing and I have a new water pump and low temp stat. I think it's a function of these cars and possibly the amount of distance the coolant has to travel to do full loop of the cooling system it takes a while for the temp to cool down.

How warm does your car get? Have you used the console 'Hack' (Recirculating & Air up buttons for 5 seconds) to see the actual temp?

Haven to done the hack but I will now that I know about it. At freeway speeds the needle is right at 12 o'clock. Stuck in traffic or going uphill in the canyons spiritedly it slowly gets to the "0" mark. A couple weeks back it was 115 degrees in the "valley" of LA. I was stuck behind a minivan going 15 mph uphill for approx 20 mins. Gauge went just past the last white line. Was about to shut it down but then crested to top of the hill, picked up speed toward Malibu where the temp dropped to 75 degrees. Car came back down to 180 pretty quickly. Here in LA there can be 40 degree differences in temps within a 20 minute drive. The pics were taken 36 miles apart!

The suggested LTT is fine and I found general consensus that it makes sense to get it installed. Difficult to judge of course from a distance but my observation would be that your car is still running relatively hot. Although the LTT will help in offering more cooling volume more quickly once fully open (so >180F) it will not make a difference anymore. Another general consensus is to replace the waterpump at a certain interval. On my car it was 19 years old so I opted to get it replaced even if it still worked fine. With LTT, new waterpump, rads cleaned, coolant flushed and fans running as they should your next option would be to replace the rads themselves and/or place a 3rd radiator to add cooling capacity.

Once again,. Thank you for the input. After looking at the cost of parts....New fans, water pump, and thermostat I have decided to sell the car.... Just kidding... Actually I broke down and ordered the Durmeteric enthusist version. Figure it will come in handy and really isn't all that expensive compared to buying parts I may or may NOT need. I will post updates in the coming weeks.

Durametric cable arrived today. Plan to download and configure the software this week. I will post results this weekend.

So just a thought, we are all hung up on the coolant temperature, since it serves as a proxy for oil temperature. So is there a temp sensor for oil in the engine?

^+1 what he said (the temp hack is cool and new to me - I'll try it tonight on the drive home. Thanks for posting it!)

I copied this from HRG / Pistonheads post.So 1c is oil temperature? I read somewhere else this is measured from the oil level sensor ? The AC Climatronic unit is actually manufactured by Audi. There is some sort of serial data stream (not CAN) that allows the AC unit to display engine parameters. This works on 1997-2000 boxsters/996 To switch from F to C: Hold down the recirculating button then push both the temperature + - buttons. To access diagnostics: Hold down the Recirculating & Air up buttons for 5 seconds. The + - buttons go up and down through the list of "c" codes. The center vent button switches the left display between the "c" code and its actual value. Press the Auto button to exit. Here is a list of what can be seen: 0c - ERL 1c - Oil Temp? 2c - Inside temp. Sensor mounted in the aspirator assembly at the side of the dash. 3c - Outside temp. Sensor located inside the air inlet of the A/C unit. 4c - Outside temp. Sensor located in front grill of the radiator. The data is fed to the Climatronic from the instrument cluster. When not moving, the instrument cluster OBC temp display retains it's last setting until moving. This is to prevent heat emanating from the radiator affecting the temperature sensor. The A/C unit uses the lower of the two outside air temp values in determining fresh-air temp. 5c - Outside temp. (matches with OBC outside temp display) 6c - Coolant temp. 7c - Footwell discharge temp. 8c - Sun sensor (dash top) 9c - Sun sensor. 10c - Passenger compartment fan speed. 11c - Passenger compartment fan voltage. 12c - Temperature mix Flap command 1=COLD, 100=HOT 13c - Temperature mix Flap position 14c - Central Flap command 15c - Central Flap position 16c - Footwell/Defrost Flap command 17c - Footwell/Defrost Flap position 18c - Recirculation Valve command 1=OFF, 100=RECIRC 19c - Recirculation Valve position (feedback) 20c - Vehicle speed in kph, updating only once per second. (real speed, not speed+safety margin as in the speedometer) 21c - Engine RPM in hundreds. This too only updates once per second. 22c - ? 23c - ? 24c - Sun sensor, exterior lights switch & panel lights control (term. 58 & 58d voltage) - used for A/C panel display illum. 25c - ? 26c - ? 27c - ? 28c - Fan speed? 29c - ? 30c - Engine run time in seconds (255 max.)(=0xff) 31c - Timing counter 32c - Displays test 33c - Software version? Mine states 3.4 34c - ? 35c - Outside temp. from inlet sensor (filtered?) 36c - temp?

After seeing this thread, I've been watching my temp closely here in hot DFW. My car doesn't get nearly as hot on the factory gauge. Now factory gauges aren't all that for perfect measurement but I'm getting up to about 190-195 max which is what most modern thermostats are set at. Ive been daily driving mine in all sorts of traffic and heat since my wife's SUV was stolen recently. The 996 should go back to fun only duty soon.

I was first confused when starting the engine this morning and the readout at C01. It read something like 145C?? Then when I went driving it dropped to 95C while coolant temp was 80C or there about. I should be doing some high speed driving this weekend so curious about what temperatures I'd see then. The 95C is in the sump so assume oil will be hotter elsewhere in the engine. So above 100C, boiling off any water. Only question: if water is in the oil, where does it go when boiling off?

^ Simply - out the AOS (crankcase breather) and recycled through the engine intake to be burned off.

Got the Durmeteric software up and running this morning. Fans are working (low/high) and no fault codes. The ECU shows the coolant temp is 3-4c lower than the console dash digital readout shows. So when the readout showed 110c the other day it was really 106-107c. After cleaning out the radiators the temp, according to the dash readout, didn't go above 105c which really 101-102c. I am going to do a final test later at the hottest part of the day but I don't think I have an issue. Thoughts??? ​

Did the HVAC hack today. Temp got up to 108c in stop and go freeway traffic. 93 deg outside temp. When moving it went down to 100c. The car does not like sitting in warm weather. In the spring it ran way cooler in stop and go situations.

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I agree, I don't think you have a problem.

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Yep, I figured my air-cooled 3.2 Carrera didn't like stop and go traffic and that the 996 would be different. Nope.

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I've read through the several posts about the AC fan hack. Still a little confused. Does anyone have photos or diagrams showing exactly what to do? Is there a way to keep the fans controlled by the ECU and also add a awitch to turn on?

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That value at c01 is not oil temp. I dont know what value it is but it definitely isn't oil temp. I have went through all the values and none of them correlate to oil temp. It would be nice if they did, but I haven't found any. Only way I know to get the oil temp is with Durametric, PST2, PIWIS ,PIWIS I, PIWIS II.

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Correct, there is no oil temp on the HVAC hack. However, there IS an oil temp sensor when you hook up a Durametric cable and software. I have used and witnessed this.

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Hmm, unfortunate! Whatever it is, today at start at the value is 145, then during driving it sits between 90-100 somewhere. This picture I shot after first driving 180-200km/h on Autobahn, then got caught in a sudden traffic jam, moving slowly in 1st gear for 5 minutes. I do believe the LTT makes a lot of sense since it will be fully open during normal driving (at 82C) while the normal thermostat will be somewhere between closed & open but definitely not fully open at 99C. In the traffic jam temperature got to 88C but not above.

Today was 85F+ in Portland, Or. I took the car for a spirited drive and got stuck in a bit of stop and go traffic. The digital readout temp displayed 105C for a brief time (in traffic) and the Durametric showed 101C. Fans kick on high and temp went below 98C. In summary, cleaning the radiators made a 4-5C difference in the overall temp. The Durametric showed the car wasn't actually reaching 105 or 110C (from my initial post). I ordered a Porsche Engine Coolant Temperature Sensor from FCP Euro since there is a difference between the digital readout and Durametric. Not sure if that will resolve the difference but the part was only $35 and is relatively easy to swap. Glad I spent the $$ on the Durametric.

My temperature is normally slightly past the 180 mark, somtimes going to the 12 o'clock position. This morning I was driving mildly hard around town, and when I reached back home, I saw that my temperature guage was on the right side of the '0', which is higher than normal. I did not know if I should be concerned that my temperature was higher than normal.

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^^This^^ Wow...no question as to why that engine was running hot! The remaining question being, "did you/they find all the pieces of the impeller?

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A lot of cars do this. Mine included. Did you have the AC (snowflake) turned on? If not, the front fans might no turn on and your temps will climb. Mine will just climb and climb until the fans kick on. When it�s really hot outside, even the low speed fans aren�t enough to keep temps at bay. The high speed fans will, though, but it takes a few mins. In my opinion, these temps are pretty darn warm. Outside of the 0 on my car is about 107-109C.

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I did not have the AC on. What temperature does the fans come on? Where should my temp gauge be when the fans kick in?

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When you press the AC button, the two front fans come on at low speed and stay on at low speed. This is almost a required action for our car�s to stay cool, and I believe it even states that this is the preferred operation in the manual. �Engine Thermostat The OEM thermostat starts to open at 187 degrees and is fully open at 210 degrees. Between the 8 and 0 is 194F, Right in the middle of 0 is 100C. Right edge of 0 is 103-105C. Bruce Anderson's air-cooled temp chart (still applies to liquid cooled cars to some degree, because oil temp is related to overall temp, and oil can be responsible for nearly 1/2 of all cooling of an engine): 180-220 is normal 230 is warm 240 is hot 250 is too damn hot Electric fans There are two radiator modules installed in the front of the vehicle (on the left- and right-hand side). These radiators are each fitted with an electric fan. They can be operated at two speeds and are activated by the DME control unit whenever the following conditions apply: Electric fan, speed 1 (Ground to DME control unit, terminal 35) Coolant temperature higher than 96.75�C or air conditioning switched on. Electric fan, speed 2 (Ground to DME control unit, terminal 36) Coolant temperature > 102�C or air-conditioning fluid pressure switch closed (coolant pressure > 16 bar). Note: The electric fans for the radiators are only triggered when the engine is running! Engine bay fan: The engine compartment purge fan rarely comes on. This fan will not really cool the engine, but instead, keep the engine bay from getting too hot. From the service manual... "Switch-on conditions for engine compartment fan (this fan pulls air into the engine compartment) The engine compartment fan is switched on when the engine compartment temperature is > 176 degrees F or the coolant temperature is > 216 degrees F. After-running of engine compartment fan If the ignition is switched off and the engine compartment temperature is more than 140 degrees F, the DME control module remains in readiness for another 20 minutes. During this time, the engine compartment temperature is retrieved every 10 seconds. If the engine compartment temperature is > 185 degrees F , the engine compartment fan is switched on for 20 seconds. If the engine compartment temperature is still > 185 degrees F after this time, the fan remains on for a further 30 seconds." Here is the long explanation from the service manual on the flashing coolant light (on the dash): "Four functions of the coolant warning light: 1. Engine coolant level too low -- light flashes slowly (0.5 Hz) 2. Engine compartment temperature too high -- light flashes slowly (0.5 Hz) (engine compartment blower might be faulty) 3. Engine coolant temperature too high -- light is lit; pointer on the right 4. Temperature sensor at water outlet faulty -- light flashes rapidly (1 Hz) ; pointer on the right Note: The temperature warning in point three is indicated if the conditions "engine coolant temperature too high" and "engine coolant level too low" are present simultaneously."

This is excellent information. Yesterday i went on skne backroads driving, and after stopping, my friends always leave their BMWs on to cool down. Is this a good practice to leave the car on for a few minutes to cool down? How long would i leave it on? I have a C2 3.4.

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It depends. It makes sense to cool things down for a few mins after a hard run by slowing down to normal speed and allowing air to move through the brakes and heat exchangers (radiators, oil coolers, trans coolers, etc. This is best accomplished on the cool down lap after tracking the car, and if the engine and brakes are hot, you can watch the gauge actually drop a bit. If you have no time to do this, then the car should idle for a few mins, with the AC button on, but then should not idle any longer. Idling for more than a few mins actually doesn�t cool the engine down at all, unless the car is equipped with post-shutdown active cooling (such as the Dodge Demon). Our car�s don�t have active cooling aside from the engine bay fan, but that fan doesn�t actually cool the engine itself.

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Do your friends happen to have turbo BMWs? My guess is that they are leaving their engines running to help cool the turbos before shutting them off. The e90 335i has expensive turbos and there may be some value letting the engine run for a few minutes after a particularly hard workout. Although the n54 engine does use an electric coolant pump and will run the coolant through the turbos after the engine is shut off, so the value in letting the car idle is debatable.

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+!, nothing cools my 996 like cruising above 40mph. Stop & go or waiting around in idle keep temps elevated.

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Excellent information in this tread again. Yes, one friend has a 2018 M3, and the other has a 500+ hp 335i, single turbo conversion very much built. When we stop, I have my car off, and they have their cars cooling down. Good to know that I am not doing anything majorly bad to my car. Although my car had the least hp, mine was the most fun driving through the twisties. This was my first time really hitting the twisties hard, and going on a group drive.

Year 2000 had these issues. Shortly after Porsche put in switch rather than rheostat to show engine temp either Cold, Warm or Hot. No in between. Both of my 2000 996 have done this. Complete cooling system and third radiator ALL replaced. No change. Save your money!!!! It's normal! But as another lister posted picture of water pump impellers could be culprit...

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If anything, those BMW folks aren�t doing their engines any favors. I have a BMW friend that like to start his M46 in the cold and let it idle for 20 mins to warm up. Not the best idea. That same guy let his engine idle for 15 mins after leaving the track. Also not good. Then, he waits until the last minute to start his car before heading out to the track - not good either, as he starts whomping on it before it fully gets up to temp. It must be a BMW thing, lol. Glad to hear the 996 was the most fun. I�d agree with that when compared to a new M3 or a 335, but when compared to an older M3 or the 135, it might be a closer comparison.

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Yeah, I think the 99s are also like this.

I have a 2000 C2. In temps above 80ish it runs at or a little above the third white line (Not Red Line). I had a coolant flush and had the radiators cleaned (bumper off). Didn't change the running temp. I used the Durametric tool to evaluate the actual running temperature. Turns out it was running in the low to mid 220s depending on whether I was driving or sitting in traffic. Turns out, from what my indy said, that there isn't an issue...hmmmm

Newer 996 owner here. After a 30 minute commute: stop and go traffic warm up, 15 miles sustained 80-105 cruising, stop and go and then park. Temps between 212-224 and all fans running, including engine fan after-run. 75-80 degree ambient temp and the temp needle is pointing to the 0 in 180. I'm going to clean the radiators and replace the WP and t-stat for good measure, however it seems to be the normal operating temp for these cars. HOT.

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The best thing to do to cool things down is driving on the highway at easy steady speed, so low load on the engine and enough air going through the rads, and then keeping it revved higher around 3500-4000rpm. This makes the water pump spin fast and to pump a lot of coolant through the block. When doing so I see oil temperatures drop considerably fast as more and cooler coolant also flows through the oil/water heat exchanger. Idling after a hard drive is not so effective as the easy high rev cooling off drive. The coolant needs the air flowing trough the roads to cool. No fan can compensate for driving wind. Idling only makes the coolant and block heat up more, till the fans go on. My coolant is steady at 80-90 degC independent the driving conditions and ambient temperatures (Oil is 90-110 degC). Coolant reaches the higher eighties only when in stop and go traffic, or idling, guess what, when there is not enough driving wind. My fans are reprogrammed to kick in at a lower temperature and get their value from another sensor at a better location. My car is a 2002 996 C2 with Relocated LTT, GT3 waterpump

So,leaving the ac button on is actually better for cooling the temps? I have a new water pump, low stat and new coolant and I'm still running around what others have posted in their pictures...

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In city stop and go driving...yes. Having the AC on triggers the low speed fans on automatically. With the AC off, the fans only come on based on the engine temperature. At speeds above 40-45 MPH, probably not as important because there is enough air flow through the radiators to keep things cool.

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Yes, Its basically all I do. Without it, 107C easily. With AC on, I�m 3-6C cooler. Try it and report back. Note: I don�t wait until my temps are high, because it can take a long time to start cooling down. I turn on the AC before the car gets hot.

That's good info. the car has been getting some transformation recently and yesterday was my 1st decent ride and temps were up. I'll try this out and report back... thanks

I was also having the car running a bit hot (~95c cruising at 100kmh and ~98/102c in traffic with external temp of 24c and a/c off) - (measurement done with durametric) I decided to replace the water pump with a GT3 one, this one has a different size pully wich will make it spin faster than the stock at same engine rpm, so ideally the water should circulate faster in the system. (had to replace the drive belt as well as the stock would not fit anymore) I also replaced the thermostat with a low temp one (71C/161F). I am pretty happy with the result, now the car is running between 78c and 82c when cruising and around 88c in heavy traffic!!!!

Spins faster means smaller pulley ...

[Image-only post; no author-written text. Original image references:] https://rennlist.com/forums/images/smilies/biggrin.gif

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Interesting, do you have a part number for that water pump and belt? (or the length) I might consider that mod in the future. EDIT: its this one right? metal impeller too https://www.pelicanparts.com/More_In...BoCev0QAvD_BwE

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Water Pump https://www.pelicanparts.com/More_Info/99610601177.htm?pn=996-106-011-77-M52&SVSVSI=905 Thermostat https://www.pelicanparts.com/More_Info/99610601359.htm?pn=996-106-013-59-M902&SVSVSI=905 For the belt I don't have a part number as this issue came out during the fitting by the garage, I'll try to came back to you for this.

This is perfectly normal. I've taken my car to my mechanic for this same issue and he's reassured me there's nothing wrong at all (and my mechanic is definitely the best you can find in my area of the country). My 996 is also a daily driver, and I took it on a 3600 mile road trip early this year. It runs, drives, performs, and sounds like it should. My 996 is a 2001 C2. Save Save

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Cool, I believe the belt should have printed on it the length in mm if nothing else.

^^ Well, it can be normal, but only usually in stop and go traffic and shouldn�t really happen on the highway with all that air flowing into the radiators. I should also mention that leaving the AC button on has another advantage (over just the fact that the low speed fans are on: If the AC pressure reaches a certain threshold, the high speed fans will kick on regardless of the engine temp. Both of these reasons contribute to an overall lower engine temperature and might just be the reason the owners manual tells folks to use the �automatic climate� feature (which keeps the AC button always activated).

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Any update?

So I hooked up a Durametric and found that the temps on the dash/HVAC are off by as much as 9-12 degrees! Temps way past the zero and we�ll over 110C are still just fine (96C). The low and high speed fans don�t kick on because they don�t need to.

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I totally forgot to check with my ac on. I haven't seen much change otherwise with it off. Gets to the end of the zero and creeps towards the line but that's as far as she went. I will test it out with the ac on or even automatic climate control as some suggested.

As a previous poster suggested, be sure to pull your bumper cover and clean the radiators out. When people install a low temp thermostat and don't see a gain, typically it is because the radiators are all plugged up. The factory thermostat doesn't start to open until 186F and isn't fully open until about 210F, so that's why it's easy to see temperatures in the 210-220F with a factory thermostat. Highway speeds where there is sufficient airflow will bring those temperatures down. A low temp thermostat starts to open at 160F and is open fully at 185F, so it's likely not going to cycle open and closed like a factory thermostat will during normal operation.

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What is a good brand low temperature thermostat?

Quotes source post: 15114979

We make our own - we take a 160F Motorad thermostat from another application and modify them - both the M96/M97 and then the later 9A1 low temp thermostats.

This is what mine was showing today.

Prepping for an HPDE and catching up deferred maintenance. Fresh coolant, WP, low temp tstat, no apparent issues. These were my rads yesterday...bottom 2-3" was submersed in soil/sand/compost.

I had cleaned mine last year. When i installed 3rd rad last month, I already had a not insignificant amount of debris starting to collect. That was less than 4k mi. Clean your rads peeps, cheap easy love for your Carrera!