Hi guys,

I have done a good amount of searching, but I would like some opinions on my exact issue. On the street, my car sees ~200F, but once I get on the freeway, after 5-10 minutes of driving, my water temps drop to 160, sometimes even to 155. I don't have any cooling mods save an AST.

On a side note, I recently installed the belly pan, and saw a temperature drop of about 20 on the freeway, but pretty much none on the street.

SO my question is: are my symptoms indicative of a bad water pump or t-stat housing? Or can there be some other issue?

Thanks,
-Daniel

 

What was ambient?

 

Where are you measuring?

 

I'm measuring in the TB line.

 

Double post

 

What he said

 

You may have a T-stat stuck open. It would run open in high demand scenarios like sitting in traffic, but once you've got airflow on the highway, it can't close down to keep the car up to temp. Does it take a long time to warm up?

 

I have similar temps. Are there "risks" to running too cool other than the time to warm up?

Highway will cool to 160 and pretty much hang there as long as you're moving at highway speeds.

 

By ambient, do you mean what is the temp outside the car? It was about 60 degrees F and very cold wind. I'm not sure how long a "while" means, but it takes about 10 minutes for me to reach 180 on the street.

 

Bad thermostat. When I drilled a hole in mine it did the same.

Don't do drive long term at temps that low. Ecu will restrict timing and I believe limit boost on secondary turbo. Not to mention if the car isn't warm enough it will not run efficiently with afr.

 

The thing that makes me think its not the t stat is that my heater works fine. Or is that possible with a stuck open t stat? Is there a way to test the one I have without damaging it while pulling it out incase it's fine so I can re use it?

 

The problem is your sender location. I had a TB coolant line sender. It consistently showed much lower readings than my t-stat housing sender, and it was always on the freeway.

There is nothing wrong with your car, and you dont need to do anything ....... except maybe relocate your sender.

 

edit

 

Thanks for all the insight guys. Adam, Before I put the belly pan on, my temps were between 180-200 highway - city. Now its 160 - 200 Highway city. I don't think its the sender, because I'm having 0 secondary boost on the freeway, and from what I've read that indicated that the car isn't warm enough yet (I have no boost leaks).

However the stock needle doesn't move at all, but IIRC the middle range is 150-230, so I don't know if I can use the stock one to judge. Is there a way to test the thermostat and re use it?