My friend's 997TT is having issues with the coolant temp sensor and a very hard time starting when cold.

it almost flooded the engine when cold, i had to try so many times just to fire it up, but once it gets warmed up a bit, it starts up normal.

once started up, the temp gauge reads 0, and the cluster reads "Failture Indicator" with a water temp symbol next to it.

we switched a good sensor from another 997TT but it still does the same thing.

with the porsche diagnostic tool plugged in, the water temp reading is MINUS -48 degree Celsius.

We attempted to short the connector of the coolant temp sensor, now it reads 20 Celsius. when shorted, the car starts up normal. This means there the connectivity from the sensor to DME is normal, since it reacts to the short.


Has anyone experienced anything like this? Any thoughts on what might be causing the issue?

Even a faulty sensor should no way read minus 48 deg right? it's the same even after switched to another one.


We can't take it to the dealer because it has aftermarket turbo kit and DME ref lash.


Help please!

 

I'm responding to your post b/c I have had the same problem more than once on my 07 and my TT is bone stock. The dealer just (purportedly) replaces the sensor that indicates failure and that is it. The temp. gauge acts as if its cold and then the "failure" signal come on. Once the car warms up the failure light goes off. My TT has approx. 48K miles on her, but I really don't think the mileage is an issue. It may just be a problem with this engine (like my 03 X50 had synchro issues). Sorry I don't have an answer for you.

 

You didn't say what year model. Unless you're worried about a warranty issue why not take it to the dealer?

 

I hate to say it but rodent damage? I had a similar expierence but with oil pressure and temp. Good luck, oh yeah it wasn't cheap in my case.

 

I had the same experience as Tortesq1. Dealer replaced at no charge. Mine is a 2007.

 

Ironically, I just had the problem again (for the 3rd time since June, 2007) and brought the car to my dealer. They said they will just replace the temperature sensor, which isn't a big deal, but then again, my car is still within the 6 yr./100K warranty (Porsche certified her after my 4 yr. lease expired). I think most cars have repetitive product defect issues that only become well known (ie. public knowledge) after a slew of use publicly discuss same. Our TT's are not immune from these gremlins.

 

FYI If the cause of the failure is not due by aftermarket parts that's on your car Porsche CAN NOT void your warranty on this repair.

Sounds like you have a short somewhere or some type of elect. issue. If the problem haven't got resolve, I would love to take a look at it for you. One of my technician just left the Porsche dealer not too long ago and his a Porsche Premier Technician, 2011 Trained and certified from PCNA. I'm curious about your issue. No obligations if you bring the car in.

 

i wish i can bring the car in, but the cars are at China.......... i ordered new temp sensors i'll have them replace it and see what happens.

 

hi my friend ! i have the same problem with my 997tt 2007, put also with 2 guages and the oil temp! i order the water temp sensor for now and we see the result!

 

ok my friend! job done! i change the engine temperature sensor and the car now is perfect like a normal!

 

guys sorry for the late reply..... i've just visited the shop in China again, and we fixed the coolant temp issue. just simply get a new sensor from porsche.

 

Hello there , sorry to re open the thread ,

I have weird issue that , my car (997tt) have very very cold coolant , when I started the car in cold start , it took 15 mins to warm and oil temp reach 70c !
And if I go and run the car with stable speed , water temp gauge went down till then oil temp went down , the weather temp is 20c !!! So it's not that much cold , even am running CSF radiator (center) !!!! I do not think this is the reason !!!


So I replaced both ( coolant temp sensor and and thermostat just in case ) but still the same problem !!!!!!!!!!!

Do you think the CSF radiator effect that much ???? Car is 1000hp , even if I do hard run from 100 to 250 , when I took my feet from the throttle and drive normal , coolant temp go down to 70c !!!!!!!!!!! Then the oil temp went down to 60c or 70c !!!


What do you think ???

 

You may have a defective thermostat - basically the thermostat is sticking in the fully open position all the time which is effecting the temperatures. I know you stated you replaced the thermostat but definitely have a local shop in Kuwait visit this to ensure it's not faulty still.

It'd be wise to have that shop take a look at how the CSF radiator is affecting things also!

 

[QUOTE=HOUSE Motorsports;4249475]You may have a defective thermostat - basically the thermostat is sticking in the fully open position all the time which is effecting the temperatures. I know you stated you replaced the thermostat but definitely have a local shop in Kuwait visit this to ensure it's not faulty still.

It'd be wise to have that shop take a look at how the CSF radiator is affecting things also![/QUOTE


Thanks for your reply ,

You may be right , but the thing that make me do not believe it's the radiator is when I warm the engine .. It took 20 mins to make coolant / oil temp higher !!


So I said it may be the thromostat , but I just changed !!!! So it's make me mad lol

Weird :/

 

Anyone feel this problem ???

The weird thing , even when the weather temp 20c , and I go for normal drive in highway , the temp go down to 70c then 60c !! It never stay to normal coolant temp !!!!! Is 20c is too much cold ? Reaching 20 mins to warm the car and the weather is 15c !!

It's weird , I just changed the thermostat , not sure if it's !