The other day it overheated at higher speeds and/or uphill. I have just replaced the Coolant Temperature Sensor thinking that was my trouble. It wasn't. Still overheated. There is steam coming from near the heater core just before the windshield in front of the drivers side, hopefully that's a good description. The hoses are hot going into and from the radiator. The fans do not come on at all. Hoping it's just the fan switch and not the whole thing, will be testing to see if that's it later. The fans do move easily when moved by hand. Perhaps I will change the thermostat while I am at it. The temperate gauge on the dash doesn't go over the midway point and doesn't change. It's a V6 2.8L Quattro.

Anyway, I am looking for ideas as to what may be the ultimate trouble. The water pump does seem fine, no leakage or anything. Just has the belt replaced. Heater comes on fine. There is clearly pressure in the coolant system with the steam coming out. Everything else appears fine.

Any help is always useful. I'm in Park City, UT for another few weeks if anyone is around that could help.

Update: Spoke to a mechanic I know and he said it may be a leak in the hose for the heater. Which is where the steam seems to be coming from. Hoping that's it, but still up for suggestions.

 

Are you saying you "think" it overheated? How do you know it overheated if the gauge has never gone past the midway point?

The coolant system gets extremely hot and is under severe pressure. a pinhole leak could produce the "steam" you are talking about. Might not notice any loss of coolant for a while.

 

It's overheating because it's not cooling down. So, kind of. It would make sense to say you're right. I am thinking it is a minor hole somehow in the hose as I am hearing the hissing sound before I see steam. The coolant definitely is lost in the same area as it's wet and I have to fill it up again.

Thank you for the reply. Does help reinforce that it's the hose that has a hole in it or loose or something. Potentially easy fix, I hope.

 

There should not be any steam coming out of those hoses going to the heater core. Sure sounds like a leak to me.

But you say that the temp gauge does not go above half-way point. So if the gauge and the sensor are working then the car has not overheated. Half-way point is normal operating temp.

 

There is certainly a leak where the steam is. Saw it today, spurting fluid and steaming up. Tightened the hose clamps to no avail. Looks like new ones are in store. Hopefully, that will end the issue.


Thanks for the help.