Common Operating Levels

I am somewhat newer to the 996 scene, being that I only have a couple thousand miles under the belt. What are the common operating levels for oil pressure, temp, coolant temp, etc. Maybe it is just do to the extreme Vegas heat, but the last couple days, the car doesn't seem to be running as it should. Last 2 days, especially on the way home (5pm and 110-113º outside), the coolant temp seemed to be rising. The oil pressure seems a bit low. Battery voltage looks ok, but the meter I have on my phone plugged in is showing 12.5V, which would be low. Idle is sitting at 750 RPM. Here is a where everything is sitting as I got to work this morning. Again, coolant temps look high, oil pressure looks low. 2000 911 C2 Cab w/ manual transmission. As you can see, just shy of 97k miles. Things I know have been done recently: New battery - 3 weeks ago Oil/Filter Change - Mobile1 0W-40 Syntheic - last night - this was rather dirty, but I didn't see any metal or foreign pieces in the filter Transmission oil drained and filled - last night What would cause the low voltage? Only accessories plugged in are Valentine 1 and my cell phone What to look for with the cooling system? Level looks fine. I plan on flushing this over the weekend as I don't know when it was done last. Oil pressure - I see the sending units are a common failure, along with the pressure relief valve. Could something with the low voltage and higher temps be causing this too? Ideas to look into tonight, this weekend, etc... Thanks!

I really don't see anything wrong here expect the engine temps. It's getting too high. I'm in the south where outdoor temps are hitting the 100F mark and both of my Carreras stayed at 180F or less. Question, how long were you driving before you got these readings?

Quotes source post: 4729557

Quote: What would cause the low voltage? If the car is idling and you check the terminals and the voltage is not near 13.8VDC, then more than likely the alternator and/or voltage regulator is going out. When the voltage exceeds threshold (14.4V High side or 9.9VDC on the low side) you should get a battery voltage warning. What to look for with the cooling system? The most common failure on the engine cooling system is the water pump. Of course, if the water pump impellers have broken off, then you may have a blockage which would result in higher temps. Also, it's also a good idea to swap out the thermostat with a 160F low temp version from LN RE: Oil Pressure The oil pressure should read around 2-2.5 at idle. It should read above 4 bar at 3000+ rpm. It's a good idea the next time you change oil, to drop the pan and inspect the oil pump for blockages

On my '99, I have a new water pump, JUST cleaned the radiators [ a real pain what with the bumper cover & all] and my temp gauge needle now normally sits at high noon w/o the AC, just to the right with the AC on. 82,500 miles.

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Quote: Hey Kevin, Have you thought about removing the front bumper? I believe that probably the only way to get the job done right. On my last Carrera, I regularly vacuumed the air ducts out with the bumper one thinking it was completely clean. But decided to remove the bumper. You wouldn't believe how much crap was crammed between the two rads. Cheers!

That's actually what I meant: I took off the whole cover and took the opportunity to install some screens thereon. [I guess I meant that the actual bumper does not come off the car - just the cover - semantics ] I took some photos, but they look like all the others. Loads of crud between the radiators and condensers - everything from dried weeds to feathers. I used a still brush first, then a shop vac, then I washed them out with a good stream of water. I could not bring myself to use the power washer on those units. Even with all that, the temp still climbs up there. I should have had a lower temp thermo installed when we did the engine -out for the IMS, main seal, chain quides, tensioners, AOS, water pump....etc, but my guy still says this temp is still acceptable. When it hits 200 or the little red light starts flashing, time to take action.

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Quote: Wow man! You've been busy! How did you learn to remove the bumper skin safely? YouTube??? Share links?

I have to confess that I did use a YouTube vid to remove the front flappy bumper cover. I watched it a lot. I kept it on my tablet in the garage whilst removing it, just in case I forgot something. Took my time. The car was rolled outside for the serious cleaning, then back in to put the cover back on...which takes a LOT longer than removal. You have to finesse it back on there. I also took the time to replace the missing screws and spacers that a previous owner/mechanic/fool left off when they put it back on last. I hate corners getting cut, especially since this thing is held on by a complicated series of screws and fasteners. Removal: <iframe width="560" height="315" src="https://www.youtube.com/embed/Um-h2aUJHY4" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe> Cleaning: <iframe width="560" height="315" src="https://www.youtube.com/embed/3xhw_hWpisY" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

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Quote: Amen! I'm the same way. When I do a job, I replace all the parts that the previous owner forgot to reinstall or broke. And, I'm must admit I'm a little OCD too. Last time I was repairing a trim piece on the seat belt panel and dropped one of the metal retaining clips down deep in the panel. Took me two hours to find it with a magnetic probe. That little thing had fallen down into the rocker panel. Some people would have just ignored it, but I couldn't go to sleep at night knowing I left that behind. Plus... it would be my luck that it would start bouncing around creating a new rattling noise that would drive me bonkers. hahaha

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Quote: This was after a 23 mile trip to work, maybe 30-35 mins. So stop and go, some freeway speeds.

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Quote: I will check the true voltage when I get home with a multimeter. My phone was reading 12.5V idling when I got to work, based on the 12V/cigarette socket. Is there a way to test the water pump? If I recall, this is a project to replace? Was contemplating pulling the bumper and making sure the radiators are clean. Looks to be a process as well. How involved is the thermostat swap, have not looked into that yet. When the engine was cold this morning, I was definitely seeing the 2 bars at idle and 4+ at 3000+. I was thinking the 4 bars seemed a bit high. How much of a pain is dropping the oil pan? I'm pretty mechanically inclined, but not sure about things requiring dropping the engine. Don't know if I want to get involved with that or not.

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Quote: Have you had this show on your display? If not, count your blessings. hahaha j/k

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Quote: Not hard coming off, but a little more involved going back on because you have to reseal the pan. Make sure you follow the correct procedure and not over seal it.

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Quote: haha, thankfully no. I was told the IMS was replaced in Nov 2017 with the clutch. I haven't looked through the records yet to confirm. Maybe I will go grab them from the car and take a look....and what else may have been done.

Got home and idle voltage was 13.1 and when the fans both kicked to high it dropped to 13. Had it tested and the voltage regulator is bad

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Quote: Shazaam.... glad you located the culprit to the problem. That's not too terribly a hard fix. Are you going to DIY or take it to a indy?

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Quote: I will do it. Not 100% convinced this would affect the warmer coolant temps still

so the voltage regulator. Which is correct? only item I found on sunset porsche in terms of voltage regulator And this on pelican parts.

That's a good question. I looked up the number for the first item (99661030800) with Porsche Parts of Atlanta and it shows a complete "distributor repair kit" and so I'm assuming it includes a few known wear parts in addition to the regulator? The other two, IMHO, are the basically the same part with Porsche rebranding it as OEM. That's my opinion. But I wouldn't know if there is something unique between the two parts.

#16 is the kit (99661030800).

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Quote: it also looks like one is at the battery (sunset) and the other at the alternator (pelican).

Installed the new voltage regulator. So far, the voltage is back up. Will see tomorrow how the oil pressure and coolant temps respond.

Did you do the install yourself? If so, any pics? Just planning ahead. My '99 has 84K.

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Quote: I didn't take any pics. Rather easy and straightforward. You can use the tech article from pelicanparts.com alternator replacement. When you pull the alternator out, there are 2 nuts (13mm and 15mm) and a screw to take off. Under that 3 Phillips screws. Pop of the regulator, screw in the new one, nuts and screw back in, alternator back in. be careful of the vacuum lines that are on the electric switch over. Has a couple lines attached and are brittle. One runs directly above the alternator toward front of car. Can take a pic later and point it out.

Thanks much

Quotes source post: 4729557

Quote: I purchased my 2001 Carrera Cabriolet back in Feb 2018 and have been chatting back and forth with befreak and others on my cooling system issues, somewhat similar to yours. Not charging issues, just coolant loss and excess coolant temp readings (probably above 220 degrees), unusual up here in Connecticut. Keeping the engine revs about 3,000 in stop and go traffic seems to keep the engine temp in between the 8 and 0 in the 180 digits, but that is very impractical driving into NYC. Our temps usually don't get much higher than mid-90s on a day we call sweltering. Until recently, I saw no physical evidence of coolant loss in the form of dripping, just disappearing at the rate of 1/2 oz per mile. However my expansion tank may have some cracks now. What I noticed in your dash pix was the red box just northeast of the zero in the 250 digits on the water temp gauge. Mine comes on when I am low on coolant, although the owners manual may state that it goes on for other reasons. I am planning to replace the pump, thermostat and expansion tank in a week or so.

I've heard, read, and experienced that coolant temps over 200, up to about 215 in high heat are normal for these cars. The issue is that in most cars the coolant gauge is a glorified dummy light so folks don't get alarmed when it moves. It reads closer to true temp in the Porsche. Mine always sits right on the "0" in 180 when it's warmed up and I'm not driving too hard. I've seen it get past the 0 and up to the next tick mark (which i think is 215) with no issues when in stop and go traffic in the heat with the AC or during spirited driving. I'd definitely start with removing the bumper to clean the radiators, and also manually raising the rear wing when in hot situations.

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Quote: Good advice! Here's a video to help if the OP hasn't done it before. https://www.youtube.com/watch?v=rqlXQqjy45E&t=192s and, for cleaning the rads... You Tube All the best!!!

​​​​​I have replaced the water pump and thermostat with a LN llow temp thermostat on both my 2001 and 2003 996 c2s. It is not a difficult job and there are numerous you tube videos and the pelican parts tech attic less to provide info. I also installed the center radiator kits in both vehicles. If you drain the coolant for the water pump replacement it is the perfect time to install the additional radiator (the turbos,tiptronics and 4wd cars all have the 3rd radiator as standard). I have found the cars do not get above the 8 in 180 with the extra radiators even driving up a mountain in the summer. I am in SE TN and usual temp in the summer is mid 90s.

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Quote: Can I ask why you changed the regulator for a low temp unit? What are you trying to achieve? This doesn't improve cooling, no matter what you might have read. See here for an explanation.

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Quote: I'm a advocate for low temp thermostats. The purpose of a low temperature thermostat is NOT to bring down the highest temps, but to operator more efficiently on the lowest threshold. JFP says it the best on this thread. http://forums.pelicanparts.com/porsc...hermostat.html

Yikes. Now my head REALLY hurts Thanks for the information. The discussion in that forum/thread is a lot more in-depth than the first article. I had not heard about the potential for 'hot spots' with these engines. Now I'm leaning back towards a lower temp unit.

That was an interesting read and at least I have seen a reasoned explanation, even if I may not fully agree with it.

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Quote: JAN2019 Update!! Finally tackled the cracked tank on my 01 Carrera Cab, which was diagnosed by the local Porsche dealer who did the limited PPI. Quite a job: 3 hours to get tank out; 1 hour to slide new one back in; 2 more to button it up. A couple key learnings: Fuel rail is in the way! Even dropping the engine only gave 95% of clearance needed. Recommend needle nose locking vise grips to deal with the Porsche spring hose clamps, if you don't have proper pliers. Also used cord to tie back disconnected hoses to give more room. Syphoned the antifreeze out using small tube to reach bottom of old tank, so it was nice and emply. Fingers crossed this is the needed fix.

Latest update: all those coolant loss and overheating issues in my '01 Carrera Cab were masking the underlying root cause of the overall problem ... excessive bore scoring and d-chunk failure. Interesting that none of the 'pros' (dealers and independent shops) could diagnose this correctly; they just wanted to throw more parts in to again be over-stressed and break. No mention of coolant loss, rapid temperature rise and combustion gases in the coolant seemed to ring a bell with them. Problem reached the tipping point last December, leading to the need to replace the motor. I'm now patiently waiting for the shop to certify the replacement as healthy and install. Their goal is a Porsche that can drive from East Coast to West Coast and back without failure. That's a far cry from my not being able to drive more than ten miles without having coolant loss.

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Quote: Ouch! Sorry to hear that. Shame that dealership techs couldn't properly diagnose this problem that has been well documented on the forums for so long. What are your next steps? Rebuild the engine? Sell it off as-is?

Replacement motor was sourced from the West Coast ... also from a 2001 with slightly less mileage and a really clean service record. Not doing the LN sleeves but will do the IMS and AOS. Some of the new parts I just installed in the old motor before it failed (water pump, low-temp thermostat, coils, drive belt, 3-part hose) will be transferred over, as well as other parts that are better than the donor motor (alternator, idler pulleys, etc.). Will likely use the clutch and flywheel from my car, since they are quite new. All in, this will increase my cost of ownership by $15K, but hey, I will be able to drive it like I had hoped.

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Quote: Have you bore scoped this donor motor?

Yes scoped, compression tested.

Yes scoped, compression tested.

My best advice is to replace anything that your budget will allow while the engine is out. Harder and more expensive the second time around. If you decide to rebuild the engine, Jake Raby just release a 20-part series on engine assembly of the Porsche M9X engines. Always good to learn from the best.

I do follow Jake's postings, being a gear-head and structural engineer myself. However. I don't have the budget for a 100% rebuild @ $20K+, on top of what I spent to buy the car. Best option was the vetted donor motor. Maybe if I were 40 years younger ...

Picked up my 01 Carrera Cab on Feb 18 from Butzi Gear after a motor transplant that took nearly 3 months. It's going to take me a year to unlearn watching my coolant loss and engine temp and not feeling like the engine was going to blow up at any moment. Like driving a normal car ...

"Problem reached the tipping point last December, leading to the need to replace the motor. I'm now patiently waiting for the shop to certify the replacement as healthy and install. Their goal is a Porsche that can drive from East Coast to West Coast and back without failure. That's a far cry from my not being able to drive more than ten miles without having coolant loss." I hope you used a different shop than the one that failed to identify the problems the first time around... Good luck with the new motor - I hope you get way more than $15k of enjoyment out of it

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Quote: yes it was adifferent shop recommended by a fellow PCA member who couldn't say enough positive things about the shop. The Porsche dealer and the other local, well-respected independent shop both missed diagnosing the root cause big time. Very sad that people pay them big bucks for expertise that just isn't there.