NEED HELP with overheating BAD.

[dvs_dsm]

Well let me explain what I have tried and know. First off its a 91 Talon Tsi AWD. My radiator fan doesn't come on. I'm going to try and fix that bu swapping out relay and fuse. I can't drive more than 3 miles (without a hood) without the car overheating. I replaced the Thermastat, still overheating. I did a compression check and 120 something across the board. No water in with the oil. It gets hot when it sits and idles, but doesn't overheat. I have to add water afterwards, but not sure if its from leaking or from boiling over. Does anyone have any ideas? I need to try and get this up and running good by Tues morning or Weds night at the absolute latest. Thats when I have to return the rental car from the accident. Thanks ahead of time.

[Paul]

Maybe more than one problem?

Check for leaks and make sure the cap is good.

Paul

[Zeppelin]

Like Paul said, check the cap. I had a similar problem with and old car and it was a faulty rad cap.

[dvs_dsm]

I will check the cap, but if it was the cap, I would think it would come out from there, as of right now its just coming out from the overflow bottle and not the cap. It may be leaking else where but I can't see where.

[yokotabrat]

Usually, when a radiator cap is bad, it doesn't necessarily leak from there, it just doesn't allow for as high of a pressure increase in the system. An increase in pressure means a higher boilover temperature.

[dvs_dsm]

I'll definately try the radiator cap. If there is Just water in the system, do you think that would cause it? I don't know if theres just water or if there is w/af mix. There was a hose that just got fixed and if they put just water in it, I'm going to try and flush it before I put a mixture in it.

[Zeppelin]

You won't have to flush the system to get it all out, just drain from the rediator plug. I'd definitely put some coolant in with the water.

[dvs_dsm]

I'm figuring that flushing won't hurt it, it might only make it better

[ErikW]

Ok. I may be able to help here. I just had my DSM Link show a coolant of -42 deg.! then it went erratic on me. I checked my CTS and the harness looked solid. But I unplugged it and then plugged it back in. Afterwards the readings were solid again.
http://www.geocities.com/MotorCity/Downs/7678/dsmtests.html
During this problem however I realized the fans were not coming on and the check engine light was on. Fortunately I wired my 2nd fan to come on when I push the A/C button on. Wired it just like stock. And Iturned it on before I made it home. The A/C system is pulled from the car. So the use for this is now for both fans to turn on when I need it. Good thing too. I didn't want to over heat. I came close, I'm sure.
The link above is a cool quick chart for sensor diagnose.
But the sensor that controls the fans (only?) should only be the one at the bottom of the radiator for 1g cars. For the 2g guys, you will have to post where that one is for the control.
And if the CTS is something that is relevant for fan control or not. I don't know. I haven't done the research even for that because this just happened to me.
ew