Experience with the LN Low Temp Thermostat

Bringing my 02 Cab in for a proactive water pump and thermostat as its about to roll 60,000. Asked my Indy about the LN low temp thermostat, and they said they put them in every track car. But for a street only car they did not have alot of experience with them. They said they would install one for me if I wanted, but thought it was overkill for a street car. Reading the LN site it seems like a good idea, as my car is a TIP. And I do not see much downside. "Tiptronic cars further benefit from reduced ATF temperatures, resulting in crisper shifts and extended transmission life. All these benefits with no negative side effects like failed emissions testing, check engine lights, or poor cabin heating in cold climates." Is anyone else running these on there daily driver cars that see winter temps and driving? I trust LN with my IMS..... I do not see why I shouldn't trust them with this. LOL! I did some searches and most threads were fights between the OEM and low temp guys. That is not really what I am asking for here. Just looking for those with first hand experience running this thermostat in areas of the country that get a real winter. Thanks in advance!

I installed a low temp T-stat in Sept of last year. I'm in TX. I love it, no trouble in winter here. If the engine is allowed to warm normally in winter, it will run at its regulated temp setpoint. I can't see any downside, heat kills and also heat failures are cumulative. I think the car would be better with a 160F T-stat from the start, but it may be an emissions thing. Don't forget to clean the rads and condensers up front. Makes a world of diff with clean rads and the low temp T stat.

Every engine I have built since 2007 has used one.... Most every IMS/ preventative process we've done has used one... That's more than 1,200 used. Never a problem. We developed this in Chicago winters. Charles and I tested this on runs as far away as Edmonton AB Canada.

I have a tip, and OEM thermostat. Tracked the car and never an issue:

After installing the low temp thermostat, I found a rather consistent driving temp difference of a needle width lower on the gauge; call it 10 deg. F. I removed the front bumper & cleaned the car's lifetime of radiator debris accumulation with no temp reduction realized. Your heater will be fine in cold weather, the difference at the heater ducts is virtually imperceivable.

Quotes source post: 14227575

Thanks Jake! Sold.... Ordering tomorrow.

Thanks for the feedback for everyone else who posted. Gave my radiators a pretty good cleaning last week (was a mess with leaves). Noticed the needle is now holding slightly lower on highways (it never gets more than 1/4 way on the "0" in 180F. Just trying the hit the last of the proactive stuff I had planned for the car. Already did IMS, AOS, RMS, Coils, plugs, and cam tensioner. After I do the water pump, thermostat, and belt I think I hit most of the common "should do" maintenance items.

Quotes source post: 14227528

Can you comment on how the car behaves during summer in TX with the LTT? I am here in moderate climate but on the first warmer days (70F) I was surprised to see how quickly the temperature goes up (I got a Mk.1 so I can read the cooling water temperature on the airco screen) from 90C (190F) to 107 C (225F) when slowing down from highway traffic to city traffic. At 107C I hear the left fan kicking in but still I would not expect the engine heat up so quickly when doing moderate driving at reasonable outside temperatures. How does this then work when it gets really hot? I am now planning to replace the waterpump and install a LTT. Radiators have been cleaned in spring. I also understood there is a waterpump available with a higher capacity then original (with a smaller pulley)? Shawn, you got a Mk.1 or a Mk. 2 (with dashboard locker)? Volkert

LN's LTT works as designed in my experience. It is effective in a hot climate like mine. Suggest you also consider the free & simple hack of slightly re positioning the engine compartment temperature sensor to reduce heat soak a little.

Quotes source post: 14228497

Thread or post on this? Pictures? Sounds like a great hack.

I know Texas and South Carolina have similar hot temperatures in the Summer, and I definitely plan in installing the lower temperature thermostat when I drop the engine. Along the lines of the thermostat, is there any advantage to adding the third radiator? I know the 3.4 in my car is susceptible to cracked heads.

I just replaced mine with a LN low temp(160f) along with a new (Pierburg) water pump. I won't know the effect until I get the engine back in the car (doing a bunch of other work) - hopefully another two weeks or so...

Quotes source post: 14228307

I do have a locker / glovebox.

Quotes source post: 14228535

I added one because the cost was very reasonable. It took me about 4-5 hours to do and I fabbed my own mounting frame. I don't know anything about 3.4 being more prone to cracked heads. I think there is an advantage to having a larger cooling volume. Others have disagreed with me in previous threads. YMMV

Quotes source post: 14228506

Just locate the sensor from the Pelican DIY on sensor replacement or your Parts Manual or FSM. Just remove and reposition it, securely closer to the crankcase half on Bank 1. All you are doing is putting the heat sensor in a hotter location so the fan stays on longer.

When doing the wp and thermostat you might think about also going with Evans waterless coolant . It reduces hot spots that can contribute to bore scoring and it reduces corrosion in the cooling circuit , preserving the water pump and tstat etc.

Quotes source post: 14228739

Just asking because I read somewhere that on Mk.2's Porsche, being fed up with drivers complaining about temperature swings, dampened the temperature readout on the dash so effectively you'd never see it beyond the 0 of the 180, unless it goes really out. Anyway, could be a monkey sandwich story but so I understood. Volkert

Quotes source post: 14229285

Ha its very possible. The only time I have seen it go to even half way on the "0" was when I had the AC maxxed, 93F day in stopped traffic.

Wahler also makes one complete with a housing and gasket. Not sure where LN sources the thermostat.

Quotes source post: 14230054

Not Wahler. These are custom made, then further modified at LN. The Wahler units are a knock off, and they do not start to open at the point where we designed the LN unit to open. They are also are not fully open at the same point. I have used the Wahler and noted zero differences in running temperatures over stock.

Interesting, good info. How are you testing them for the onset of opening and fully open? What temp does yours begin to open?

Quotes source post: 14228559

i did the same recently, car has been performing beautifully and it takes a lot of effort for me to get it up to temp.

Quotes source post: 14230210

thanks Jake. Can you provide further info on when the wahler begins to open and when its fully opened as compared to yours. exact numbers are not necessary if you don't want, a simple (xx degrees hotter to open, XX degrees hotter to be fully open) would do.

Quotes source post: 14229125

Is there a "mount" located there for the relocation?

Got my thermostat delivered today. Goes in on Monday with a new OEM water pump and belt. Going to have my shop pull front bumper and give the rad's a good cleaning too. Also ordered the LN oil filter adapter and spin on filter for the next oil change. Will report back after I get the car back next week.

Good plan. If you add the 3rd rad, it'll be perfect!

Well I am a believer! Water pump proactively swapped, LN low temp thermostat installed, and coolant replaced. Car is running noticeably cooler while stuck in an hour of traffic @ 90F... then it was before doing 70mph on the highway with air temps in the 40s! And it is definitely much more consistent, needle really does not move and this on the hottest day of the year. I am very impressed!! Thanks Jake and LN for a great product! This is highest it seemed to get after rolling in half hour of bumper to bumper traffic with AC on max. Used to go a bit further then the halfway mark of the "0". 2002 3.6L Tiptronic, no other cooling mods. I think Tips already have 3 Rads?

Awesome!

Here's the best explanation I've seen so far on the value of additional cooling and a LTT (specifically with regard to cylinder scoring and cracking): http://www.911uk.com/viewtopic.php?t...er=asc&start=0

Quotes source post: 14230054

My understanding is the LN unit is a modified Motorad thermostat.

So to get this correct. Motorad and other thermostat manufacturers claim a 60 Degree low thermostat for the M96 engine but these are not the same as the LN engineering low temp thermostat since the LN engineering version has aditional modifications that make it open earlier?

Quotes source post: 14383744

As I understand it there are 3 types of thermostat we're discussing in the thread: original, low temp, & LNE Original: Begins to open at 187F. Unsure who the manufacturer is for OEM products Low temp: Begins to open at 160F. A number of manufacturers produce these (Motorad, Whaler, etc.) LNE: Begins to open at 160F. Assuming they either i) purchase a low temp thermostat from one of the German manufacturers and repackage it or ii) purchase a standard thermostat from one of the German manufacturers and modify it to be low temp. Per their website: "Our 160F low temperature thermostat is not available from any other vendor and features a calibrated, German-made 160F thermostat". I've had a good experience with LNE products, but would be interested to hear how their low temp thermostat differs from the others on the market. Not sure what else you can do to a thermostat once it's already calibrated for 160.

Quotes source post: 14384496

This is correct. how does a Low temp thermostat that opens at 160F different from an LNE Low temp thermostat? I want to know if there is a real difference and if there is what it is.

2month update. Got a OBD scanner to play around with and have been watching coolant temps. 90F day, hellish 12mile roll and go commute, coolant tops out around 201F. Typically stays around 195F, and at speed in the upper 180's. On the dash, the needle gets to 150ish fast, but takes alot longer to reach 180, which I presume is a good thing (slower warm up). So I have to wait a few more minutes to get up to temp where I feel comfortable revving it out. Huge difference in the average needle position on the dash vs OE therm, makes me wonder what temps were at before! Few weeks ago took the car up to a buddies house and we switched off some spirited passes on real nice twisty hilly roads, very hot +90F day. Temps stayed perfect, although the rear fan did kick on twice after shutting car off (first time car ever did that since I have owned it). Very positive experience with the LN thermostat so far.

Good to hear your good experiences! On the LTT, it seems both Wahler and LN will open at 160F and are fully opened at 180F, so then the only difference would be the curve when transistioning from 160 to 180. Like at 170 the Wahler is open 50% and the LN at 80%. Or something like that. Only way to find out is to put both in water side by side and measure degree of opening while increasing the temperature. Anyway, I am happy with my Wahler, what I see is very similar to described above, only it seems the LN moves quicker to a more open position compared to Wahler.

Quotes source post: 14387798

Some folks who track consider 100F (oil temp) "warmed up." If you are at 150F, and you've been running the engine for 10 mins, I would think it would be considered warmed up enough to start the flogging.

Quotes source post: 14388342

o bought a Motorad LT stat and it works like described above. I tested it in a pot of water that I brought to a boil. Observed it started opening at 160F and was fully open at 180F. In the car, under normal freeway driving, it stays right at 180. In town with ac on, it stays just a tick over 180. With ac of, it will go to just past the 8 then the fans come on. I have not cleaned my radiators yet and suspect suspect they never have been. I will ill stick with it. No on to an effective oil cooler.

Slight revive of an old thread, but wanted to share an interesting observation. Installed a new water pump and LN low temp thermostat. Operating temps more stable, staying between the 8 and 0 on the gauge. While cruising on the highway, did a 4th gear pull to 7,000 rpm (professional driver closed course) and saw the temp gauge plunge to 160. As soon as I dumped back into 6th and reduced speed to 70mph, the gauge went back to its normal position. 45 degree ambient day. My observation is this is a function of: (1) higher RPM speeding up the water pump and therefore coolant flow; (2) more cold air over the rads at high speed; and (3) the thermostat having a bit of delay as it adjusts (closes) to handle the sudden new high flow rate of colder temperature coolant. Not a complaint, just a cool (pun intended) observation of the improved function of the LN thermostat.

I have the LN low temp thermo also. But I don't commute or site in traffic, where I think it benefits the most. Yes, it opens earlier, but if you're driving the car hard, it's not going to stop it from getting hot. If you're cruising under no load, I guess it helps keep things cooler. In SoCal summer, its hot one way or another I would recon if you were around 125mph, then 45F air at 125mph is your answer.

Quotes source post: 19985866

My guess is the water pump is moving more water volume. I�ve seen this on other cars - different makes and models - too.

Quotes source post: 19985866

Wow, 160 is really low! Do you have a center radiator? Have you upgraded your rads to CSF performance units, or are they stock-styled plastic ones?

Quotes source post: 19987028

It�s a 40th Anniversary, so it has the larger turbo sized front radiators. Plan was to add a third radiator, but according to some other posts here the parts don�t fit on the AE cars due to unique plumbing compared to the normal and turbo cars. New plan is to delete one of the AC condensers (like the GT3) and upgrade that radiator to CSF. At the end of the day, thermostats don�t shed heat, so on track on a hot day I will likely need more radiator, but curious to see how the AE�s turbo sized radiators handle the heat load. May be sufficient as is.

When the water pump was wearing out on my boat it would over heat in no wake zones and come back down when I got the revs back up. 7k rpm will move a lot of coolant.

Quotes source post: 19987261

Cool. It actually does sound sufficient, but it�s probably better to err on the side of caution with these engines. I think your plan to delete the condenser and upgrade the radiator is an excellent idea!

Quotes source post: 19987261

Just keep in mind that, without a fan to move the air, your temps won�t come down in road speeds below 30-40mph. For track cars, no fan is needed because of the airflow due to speed.

Quotes source post: 19987261

GT3's have 2 condensers. The PET is confusing, the drawing is wrong, but trust me they have 2 condensers. There was a thread about center radiator in a 40AE a year or 2 ago. I can't remember the outcome. I think you will be fine with only the outer radiators as far as water temps. I never see water over 185F no matter how hard I flog it on track (though I have a center radiator). Oil temp might keep an eye on, the M96 oil cooler is marginal. CSF don't cool any better than new stock radiators; they look pretty though.

Team, I live in SoCal, and probably drive my 996 cab only a few thousand miles a year. It's a 2nd car, and I will never track it. 72k miles, going in to replace my coil packs and fuel injectors (and plugs) just to be preventative for bore score and generally. For my situation - maybe in the summer if it's 90+ degrees I'm driving the car in moderate traffic or on the freeway for 20mns to an hour... Will my application at all benefit from the Low Temp thermostat? Mechanic who was super reasonable on the Coils/Injector labor quoted me over 450 for install including the part (not LNE) which seemed high, too. Thx

Quotes source post: 20031686

Do you need a LTT if you are just occaisonally driving the 996 around town in S. Cal? Not necessarily. But it does provide benefits for a cheap price as described in this thread. The perfect time to upgrade to a LTT is when you plan on replacing your water pump, which is a smart move every 5-7 years. Besides running a relatively new water pump, the most important thing you can do for cooling is to make sure your radiators are clean and your fans are functioning properly. For sure, it helps to keep your car moving when possible for air flow Plenty of other things you can do that we can discuss, but it all costs money and is track related. But can certainly help on the street.

Quotes source post: 20031686

i'm in socal too. I did the water pump and thermostat myself. It's not hard. Biggest issue of only doing thermostat is having to flush and refill coolant. Perhaps he's also including Porsche coolant in price? I wouldn't bother personally unless your are doing pump at same time. As noted above make sure you pull your bumper off and clean radiators out, you'd be amazed how much builds up in there that you can't see. What did he quote for coils/injectors? Is he doing the sleeves as well?

Not all Tips have a 3rd Radiator. A C4S Tip has larger radiators like Turbo, I don't remember the percentage, so no 3rd radiator. Looking at all of the "Clean Rads from Leaves, etc." I can see that C4S rads are bigger and mounted in a different way than non-4S cars. It is difficult to get the AC condenser-rad away from the radiators, but doable. Perhaps the 40AE has same radiators? Don't know. LTT just make sense, heat kills. The most difficult part of job is doing vac-refill with special tool for this, sort of PITA tool use once in every 5-6 years... YMMV

My opinion is that the low temp thermostat is always worth doing, but I'd never do it unless I was also doing the water pump (w/ plastic impeller) and fresh coolant at the same time.

Forgot to mention that LN Engineering has a 996 water pump kit for what I consider to be a pretty great price. $399 gets you a Pierburg water pump, an LN low temp thermostat (which appears to be made by Motorad), a Continental serpentine belt, gaskets, new bolts for the pump and tstat, and a bottle of Driven Cooling System Protector. I recently bought it and installed in my car.

Quotes source post: 20031686

Somewhere on this forum is a whitepaper advancing the theory that bore scoring is actually a result of localized overheating within the engine. So while overall coolant temps may be within design limits, this localized area gets extremely hot and may be a contributing factor to bore scoring. By lowering the overall coolant temps with the thermostat, you also reduce the hotspot temperatures, potentially avoiding bore scoring. Or so the theory goes. Seemed reasonable enough for me, considering the minimal cost of the thermostat install compared to the high cost for other engine reliability upgrades for the 996 (IMS, UAOS).

Thanks, everybody! Water pump was done in mid 2021 by prior owner. Only 5k miles on the car since then, so it seems like it's not worth touching. At that time they did spark plugs, IMS, RMS, drive belts, new Reinz thermostat, "cam plugs" or they're labeled on the parts sheed as "cyclinder head plugs), re-time engine. Since I'm not doing the pump, seems not worth doing the Low Temp Thermostat, then... at least from a labor POV. When I bought the car I scoped for bore score and it was clean. I just want to be preventative as hell, and have read up on the "LTT prevents engine hot spots" theory. In LA, was quoted 300 to replace the coils, 900 to replace the injectors. Felt reasonable vs other quotes. LMk if you feel different. This is just for labor, not parts. When asked about "Sleeves" - are you referring to - i think - spark plug tubes? Mine is a 996.2 so it doesnt have spark plug tubes? I assume you didnt mean cylinder sleeves, meaning an engine rebuild. I've had a ton of other work done to the car, and had front bumper removed and debris cleared. I also installed screens in the front. My temp hovers just above 180 in normal operation.

Quotes source post: 20032299

Sounds like your 996.2 is in great shape with refreshed parts. You know the routine, run great oil such as DT or DI amd change it a couple of times a year and your bores will thank you. If you want to add some clarity to your temps, get @Coopduc digital oil temp gauge. Very reasonable in price. It will cost you a couple of bucks to get it installed by an indy if you cant diy. It is one of my favorite parts since I can monitor both water and oil temps around town and on the track. No guesswork.

Thank you. Since I'm just driving around town/freeways I don't think I'll need that extra temp gauge but it looks nice. I change the oil annually (I'm only 2500mi/yr), have have been using Motul X-cess (spelling?) since that seems to be one of the good ones. Using 1/2 can of Driven injector defender per fill up Wondering if i should bother doing a bottle of techron before the oil change