rkellstrom

So, I have lurked for a while reading all the horrific bore score threads, IMS failures, pictures of wheels I can never rationalize affording and countless posts on how to change your oil while wearing loafers and golf shirts.

I figured I would attempt to make my first post here somewhat informational. I ordered the 160 deg thermostat a couple weeks ago. I ordered it with the tool which at the time I thought was stupid. Turns out you should use it because it is kind of a pain in the *** if you do not have it to get the new T-Stat in. The job which "should" take 15 minutes took me four hours. This job is not hard to do really, if you feel like taking off the solid coolant lines which run under the car.

I being a moron said F that, I can get around it and access the top E10 bolt. After welding up a ground down socket to a wrench handle I was able to complete the job rather then spend the extra time pulling the hard coolant lines off. Now I know to not be an idiot.

Bleeding the system was easy, I did not have much trouble. I opened the bleeder left it on a hill all night, drove around for a while the next day and it was done.

The results

So before I did this project my car would take around 10-12 minutes to heat up the oil to the fun mark which is just past the 200 deg mark. Now the car takes about 20 minutes to get to the mark but it hovers just below the line where as beofre normal driving was around 210-215 deg.

This tells me that the car is running quite a bit cooler. The oil actually takes a bit of work to get over 200 deg and when you stop driving like an phyco it cools right down to below the 200 deg line. I would assume that if I could accurately compare the before and after coolant temps it would be much cooler than previously on average.

So if you are wondering if it is worth doing, I would say yes. The car runs cooler and the fans take a lot more traffic sitting to switch on than before. This may have all been for nothing since I probably have borescoring (997 AIDS) and will have to rebuild anyways but in the meantime I may have held it off for a bit.





Here is before in red and normal driving now with new T-stat

ADias

A lower temp stat will not prevent an engine from reaching high temps - that is solely a function of the required effort. Stop borescoping your engine and drive it with the engine at the proper op temp.

rkellstrom

Yes true, once the T-Stat is open, its open and flowing. What is a fact is that the oil temps are lower. So there is more to it than I would have expected. That is why I posted this. I have read all the threads about it not making a difference. Well, it did. Maybe its magic, maybe the factory Tstat does not open/respond as well. Who the hell knows.

As far as borescoping, this does not seem to be a myth for a growing number of owners. My car does consume oil but within the BS tolerances allowed by Porsche. Tailpipes sooty? Sure. Does it tick? No more than any other engine you hear. Nothing of concern. I just drive the car. I do however run DT-40 Oil and will continue to do the small things which "could" help. The car does not get driven in winter so changing the T-stat was not a concern. If its helps prevent or hold off a potential rebuild than great.

docdrs

All a 160 over a 180 tstat does is open sooner. But it will be wide open sooner and at a lower temp which if that is your goal then you have achieved it. Will it runcooler at wot track days?????? Maybe a little, will it run cooler during DD ......yes.......will it make a difference?????? Let the games begin

motopix

My car with the central/third rad installed, stock thermostat, oil temp seldom goes above 200 (indicated) on the street. It will go to about 210 for a while then down to 200 again shortly after.

I really don't understand the hoopla about a 160 degree thermostat. Open is open.

Mike Murphy

I can totally believe that the lower t-stat could have a noticeable improvement on lower temps. The thing is, it can take a long time for a 996-997 to shed built-up heat. For a car sitting in traffic that gets going again, the lower t-stat has the cabability to remove more heat than a regular one if it's exposed to more air over time. So it will then take longer to reach high temps than a standard t-stat would after recovery.

But it's still not really going to fix issues that a 3rd radiator could fix, which is to say, you still need to remove the heat one way or another.

German888

Recently dropped in a 160 during routine maintenance. Did a test with the new 160 and OE 180 in a pan of water over a burner. Much to my horror the 180 did not begin to open til closer to 195 and never fully opened even at 225. The 160 on the other hand was spot on with movement at 158 and fully open by 175-180.

I suspect more people out there experience the difference when switching because the old 180 is not doing it's job.

Moral of the story is: your pissing up a rope unless you test both Tstats in this way before installing.

My results were very similar to the OP's in oil running temps after using OBDII real time temp monitor.

semicycler

Agreed. I also suspect a properly functioning 180 tstat is not fully open at daily driving temps, whereas a 160 is. This means less restrictions for the 160 and the observed better cooling. Whereas at track temps I bet you wouldn't notice a difference since both would be fully open.

Anyone concerned with moisture buildup in the oil if they are seeing sub-200 deg oil temps with a low temp thermostat?

kisik

In my opinion, only if you are doing track events then you need to add all possible things: 3d radiator, small bumper mods to increase air flow, low temp thermostat, extra oil, putting ice, turning heat on... different oil...upshifting sooner to keep around 5500-6300 rpm to prevent going above 250F.

For the road enthusiasts or traffic driver, I wouldn't bother especially with short trips like 10-20 min at the time preventing the oil and engine going to the right operating temperature point with 160F thermostat.

Own Goal

Two things:
Seems like we had a very long and very technical discussion on here about this by Jake Rabe and Baz from Hartech in regards to doing this to add another prevention of the nasty #6 bore scoring on 9A1's. Pretty serious players.
I've noticing the locations of everyone in this thread. No one from Texas or other super hot WX states.
I'll probably have this done next oil change. About to hit 50k and use zero oil. Sounds like reasonable insurance.

Petza914

OK, here's someone from a hotter area of the country - SC, but it was 97 degrees on the highway in Atlanta today according to the temperature gauge in my 997. My car is supercharged, but also has a 3rd radiator, low temp thermostat, and 2L deep sump. Running about 90 MPH I was seeing temps at 225 or just a hair above - this is why I run DT40, which is good to 300 degrees for short periods and has no issues at all with sustained 250 degree temps. My oil pressure was 4.5-5 bar off idle and 3 bar at idle at these temperatures. Fake coolant temp gauge said 175 all day.

The low temperature thermostat will not make your car run cooler unless your trips are so short that the 180/185 degree thermostat never really opens or only partly opens. What the LTT does contribute is a more gradual warm up of the engine, which is why it takes a longer time interval to see the same temperatures after installing it, and this more gradual warm-up is what can prevent bore scoring by preventing the #6 and #3 cylinders from getting too hot before the thermostat is opening and helping to regulate that heat.

ADias

To keep things in perspective. 911 G-series Carrera oil gauge:



Those engines routinely run at 240F and those heads are not water cooled and they hum around quite nicely. 997s running at 225-240F are just fine. On the other hand... cold engines can be an issue.

Lvt19672

I don't understand why you would want your oil temperaure below 200F like in the OP's first post.

Mike Murphy

While I cannot argue against your point, because oil should be at the ideal 100C, I can say that my cars runs between 89-93C in the winter and on the expressway according to Coolant temps, so if oil temps are generally 15 degrees higher, than even the 160F thermostats should still keep the oil in the right range.

Petza914

unless you're measuring coolant temp with an OBD2 type reader, you don't know your actual coolant temp. The gauge built into the dash for coolant temp is heavily buffered and not a real gauge - it's an idiot light disguised as a gauge.

You need oil temps to be around 220 degrees as this is the temp at which water boils and what you need to evaporate start-up condensation out of the oil. Short trips will just keep adding condensation, not only falsifying your true oil level readings, but also never evaporating away, causing your oil to foam or become milky and less protective.