I am confused as to why and what could be wrong with my 97 a4 2.8. I just had a coolant fan installed because it was not working. Then I got a check engine light and noticed that my temperature was running 2-3 spaces above the halfway mark. My mechanic noticed the fan clutch was bad. So we replaced the fan clutch. Even after replacing it the temp still read over the halfway mark. It maintain at 2-3 spaces above the halfway mark. We also replaced the coolant temp sensor and now we get a consistent temperature reading of around 217 degrees still reading the same. I just bought this car a month ago and am not sure if the temp is supposed to read above the halfway mark or if there is something else wrong with my car. I also flushed the radiator in case there was some kind of trash keeping the water from cooling effectivley. I really would appreciate some help and advice on if this is normal or what else it could be causing it to run a little warmer.
Thanks,
Desparately Seeking Advice

 

Did you change the oil? I've found that if my oil is coming up on the 3000 mark, my engine tends to run a little over the 1/2 way mark. Once it's changed it moves down about a mark below the 1/2.

 

what do you mean by 'flush'? did you replace the coolant with G12, or did you mix red and green coolant? what is the ambient temp (air temp)? it could just be your thermostat not opening all the way, or it could be a warm day out. i forget exactly how many spaces are on the temp gauge but 217* is no where near dangerous. and you didnt say that the car was overheating, so i dont see the problem here.

 

I willl change my oil and see if that helps. I flushed it and put g12 back into it. The mechanic hooked his machine and took a temp reading and it read 217. I just thought it was not normal for it to run past the halfway mark. The mechanic told me that temp was not too hot. I am not getting a engine hot light. I am hoping since I changed the temp sensor that the CEL will not come back on too.

 

my temp runs a hair over half all the time
i just got my oil changed and a brand new thermistat put in
so if that helps theres my two sense

 

your thermostat could be stuck closed. if that's the case, the coolant would never go to your radiator, just circulate through the engine, staying hot. i would try that since it's cheap. just make sure you get an OEM one, not a cheap aftermarket one cause 90% of the time they suck or have a different temp.

 

Try burping the radiator just to be sure you don't have air pockets in there. This is easy to do. Jack up the vehicle so that the thermostat is angled upward. Start the car and let it idle until it's 3/4 of the way to overheating, then shut it off and allow it to cool down somewhat. Then pop the cap, let the coolant drain down, and refill it. Restart the vehicle and repeat the process, until the coolant level doesn't drop anymore.

What you're doing is this - anytime the cooling system is opened up, especially when the fluid is drained and parts are replaced, air gets into the system. When you reassemble and refill with coolant, you trap air bubbles in the system. Since the system is sealed, it operates under pressure. As the car runs, the coolant and the air bubbles are circulated. The bubbles get caught behind the thermostat (if you have it angled upward) and keep it from opening. This causes the engine to heat up to the point of overheating. You want to allow it to get about 3/4 of the way to an overheat so that you know the air bubbles are blocking the thermostat. Shutting down the car stops it from heating up to the point of damage, and allows the system time to cool off so that when you pop the cap, you don't get an explosion of coolant in your face. Once it's cool enough to open the system, you open it and release the pressure. This allows the thermostat to open and bleed the bubbles upward to the open cap, where they "burp" into the air. The space they took up fills with coolant, which is why your coolant level drains down. You top it off and repeat to make sure that all the bubbles are out. You'll know you're in good shape when you let it run and it gets to operating temperature and doesn't overheat anymore. Let it cool that final time, open the cap, and since you have no air pockets left in the system, nothing will burp out and your coolant level won't decrease. Then you should be good to go - put the cap back on and drive away happy.

 

Upstate, Should I jack it up from the front in order to burp the radiator and when I am letting the engine cool off and opening the fill cap should I let the jack back down. Thanks for all the help on here. This site is a lifesaver.

 

That's right - either jack up the front or put it on ramps so the front is facing upward (the thermostat faces forward). You can leave it in the air the whole time you're burping it. When we did a t-belt this weekend, we did three fill-and-burp cycles to be sure all the air was out and the coolant/water level was correct. I'm betting this will solve the issue. I'm surprised the shop didn't know to do it though - it's standard procedure anytime you remove and refill coolant.

 

Running hot causes coolant to massively break down and damage to occur.

1. Flush again, but like HARD CORE this time. There is professional radiator cleaning that can be done to.
2. change thermostat
3. pray to god it's not a head gasket or water pump.