put the cel light out 3 times. everything works as it is suppose to. engine temp in the center, oil temp in center, coolant is right level, fans are working properly. cell comes on randomly. now what. dealer wants me to change themostat and housing. they will not say if it will cure issue. now what. what do you think. thanks.

 

That's a fault code you get when the engine temp hasn't warmed up as expected. Literally - the code is for a blocked thermostat. It's not a sensor reporting the problem, it's an ECU trending problem.

So, either your temp sensor is faulty and it's sending the wrong readings to the ECU, or you have a thermostat partially or completely stuck open. That could mean that the thermostat just isn't closing all the way, but it will open all the way, which may indicate why you have normal operating temps. The car knows given the load you're driving at, outside temp, and mass of air traveling through the MAF - about how long the engine should take to warm up.

So, you can either replace the temp sensor, or the thermostat, or both. You'd have to pull the sensor to actually test it to see if it's bad, but the sensor is cheap enough that you might as well just replace it rather than running through all the multi-meter tests. I would have them do the thermostat and temp sensor. The sensor is like 40 bucks, or something. Thermostat is also dirt cheap. But, the labor to get at it will be substantial.

 

This is very typical of a thermostat that has failed in the open position. Very common on the 957 models. The computer looks for a certain volume of air to pass through the engine as the temp rises to operating temp. If the temp rises too slowly, then it throws a code.

If you have a Durametric, you can reset the CEL and see how long it stays away. I did this for a year before replacing the t-stat on my '08GTS

If you do plan to do the t-stat, plan on a water pump as Porsche sees these as wear/service items.

 

Had that code on my 957 and replacement of the thermostat (and housing) solved it.

 

dealer wants to change the water distributor housing too?
be interesting to find out there is a tsb updating the housing to the current threaded version vs the old glued in version.

same code on my gts. I figured not a big deal, how hard can a thermostat be to change?
hah! I can barely get a look at the thermostat with a boroscope.
what was porsche thinking?

 

I`m 99.9% sure there was but I`ve just been on Renntech and it seems a lot or maybe even all the TSBs have been removed and theres some message about copyright or something along those lines

I also had a look on another resource I use and while theres still TSBs available I can't find the one regarding the glued in barb so I`m guessing its had a clean out too with some TSBs removed

I smell a rat here.....

 

I miss read the op, he was referring to the thermostat, I had the temp sensor on my mind.
now I need to figure out why the dealership wants to change the op's thermostat housing.
housing is 230 bucks, maybe they change to the updated aluminum pipe in the v of the engine
and the only way to do that is to change the housing.
if all of that is part of a tsb and covered it would make sense to let a dealer do the work.
dealership quoted me $650 to change the $60 thermostat, but would not tell me if that included
updating to the aluminum lower pipe and checking the glued in connection at the water manifold.

 

Got the P2181 code, assuming after all the reading it is 90% chance of faulty thermostat. Based on everything I read, the thermostat is stuck in the open position. I will reset the code and see if it comes back.

The labor to replace the thermostat is significant as it is a big job.

So if that is the scenario, should I be replacing water pump? Probably good idea as my car has about 84K miles on the odometer.

I see this updated coolant pipe for GTS.
https://www.suncoastparts.com/product/94810606910.html
Is that this only pipe to upgrade?

Anything else I am missing?

Any input is appreciated.

 

Same here. 09 Turbo S. CEL light comes on every 2-3k miles, I clear it, and it comes back in another 2-3k miles. Had it in the shop last week, a new thermostat would fix it as others have mentioned. I let it go for now until I schedule my next round of service/upgrades in the winter.

The only thing I would suggest is while you are in there, replace the water pump depending on how many miles/if its been replaced before. I replaced my water pump at 70k miles because I was doing the serp belt anyways, so if you go in for the thermostat you may as well do a new water pump since the pump itself is around $150. I was quoted $650 for the thermostat at my local Porsche guy. Seems fair to me because in doing my water pump it would take my around 3-4 hours to do the thermostat. I'm slow.

 

interesting that an updated pipe is available, my 08gts has a composite pipe.
when I replaced the thermostat and temp sensor that pipe looked like it would be difficult to replace. if you do the work post some pics, I'd like to see how the composite pipe can be removed.

I did the thermostat/temp sensor at 41k miles so did not replace the water pump, but at 84k and having it out anyway might as well replace it.
with the water pump out of the way might as well replace the drive belt too.
I also replaced the 'intake socket' 948-106-101-03 because the instructions said to, but others have reused or switched to an aluminum part.

couple links
https://rennlist.com/forums/porsche-...yenne-gts.html

http://www.pelicanparts.com/techarti...eplacement.htm

https://www.6speedonline.com/forums/...-pump-diy.html

 

^^^^^ Thank you

My indy flushed the system as it was due, he mentioned that coolant did not look good and it was difficult to drain it. So I am hoping the CEL was related to that. They ran the engine for two hours then I drove 200 miles yesterday, the engine light did not re-appear. Fingers crossed.

Just in case, anyone with the part number for the temp sensor?
It seems good idea to address if we ever there.

Thanks!!

 

the temp sensor is 997-606-420-00
I found out after replacing that there is a separate fault code for the temp sensor.
the pelican instructions indicate removing the intake as the starting point for thermostat, at that point its not too difficult to access the temp sensor.

 

Have the same code on my new to me 08. It was a pending code and I cleared it 400 miles ago. It is yet to come back on but I'm sure it's only a matter of time before it does. Let me know if your replacement fixes the issue and what it ended up costing you. Thanks!

 

70k ish thermostat stuck....replaced.
110k ish thermostat stuck again. replaced thermostat and WP.
I believe labor is around 3/4 hours for replacement.

 

Yes, replace the water pump. Porsche considers this a wear item. Also, while you are in there, replace the vent tube as well.

Check the coolant tube as well. I think it is plastic and the replacement is metal.