Running too cold

[BlknBlue2G]

My car never wants to hit normal temperature. It will stay a little below even when idling for a long period of time. While driving it gets really cold. I dont have a logger but I have an A/F gauge that still seems to cycle like its in closed loop but my gas mileage sucks and my heat is not working well either.

My fans are not always on so I am guessing my thermostat is stuck open. My coolant is clean, just replaced it when I had a hole in the hardline behind the turbo to the oil filter housing. Am I hurting anything other than my pocket by not fixing it right away?

 

[Slipstream]

Agreed, sounds like a bad tstat, iirc they're all of $10-$15 for a new one...replace it and make sure that's the problem. Your a/f gauge is of little to no use on the dsm 02 sensor.

 

[DiabloRT]

Definitely ssounds like the thermo.


I replaced mine thermo on the 92 Tsi 2 years ago as routine maintence. It worked fine, but I figured a 12 year old thermo is probably at the end of its life. So I got an OEM one from the dealer.

4 weeks ago when it started to get cold, I had the same symptoms as you. Long Idle it warms up. On the highway its overcooled, temp gauge drops, and the heat is cold.

So I got another OEM thermo from the dealer. When I removed the problem one, I was shocked to see that the U braket that holds the spring and other parts had broken off on one side. So the thermo wasn't stuck open, it just could not close enough because of the structural failure.

I would be interested in seeing if yours did the same thing.


In any event get a new one and let us know.

 

[BlknBlue2G]

I'm debating on whether I need an OEM Mitsu thermostat. They have two at Pep Boys:
One is a 195F for 11.99, other is a 180F for 12.99, plus I get a discount. They look really different though so I guess that I will have to wait til I pull it out. How much is a mitsu thermo.

Don't I want the engine running cooler? Anyone know what the OEM one begins to open at?

Ill take a picture of what it looks like when I take it out.

 

[Defiant]

I'm debating on whether I need an OEM Mitsu thermostat.

You do.

They have two at Pep Boys:
One is a 195F for 11.99, other is a 180F for 12.99, plus I get a discount. They look really different though so I guess that I will have to wait til I pull it out. How much is a mitsu thermo.

If it's fifty bucks -and it's not- it's still not too much to pay for one of the most crucial parts in the entire engine. Don't cut corners here.

Don't I want the engine running cooler?

NO. The ECU and everything else expects what the factory built it for.

Anyone know what the OEM one begins to open at?

Are you intimating that you own a DSM but don't own the shop manual? Stock is 180°F for the turbo.

Ill take a picture of what it looks like when I take it out.

We're on the edge of our seats.

 

[TimG]

We're on the edge of our seats.

Cute.

As said, go with OEM. Fuel trims also do not cycle unless you are above 190 degrees F. You will save more on gas, headaches, O2 sensors, etc in the long run if you go OEM.

 

[BlknBlue2G]

Do you think that at mitsu's factory they have a little section where they manufacture thermostats for every model car they make? Highly unlikely, they outsource and buy from the company selling them at part stores for 12 bucks but they put OEM on them and sell them for 4 times the amount.

Im pretty sure Stant knows what they are doing and have less faulty products on the shlef than mitsubishi.

 

[damentor]

Sounds like that's the explination as to why my fuel trims aren't changing from FTRL- 118.7% FTRM- 108.9% FTRH-117.5% . My temps never really reach 190* . I think I'm going to try this 192* thermostat I have sitting around from Autozone

Quick question, shouldn't I beable to see my o2 values constantly changing no matter if the car reaches that 190* operating temperature or not? I forget how that works. I only get an o2 reading occasionally if I give it full throttle or periodically while accelerating . (brand new o2 sensor btw)

Cute.

As said, go with OEM. Fuel trims also do not cycle unless you are above 190 degrees F. You will save more on gas, headaches, O2 sensors, etc in the long run if you go OEM.