Since you work at a dealer, have them plug in their VAG machine and see if the codes are there. Your fan should kick on and off, NOT run all the time....why your reservoir leaks is because somewhere there is something blocking flow, it's a high pressure system. I'd say its a sensor somewhere, since the fan won't shut off at all, and possible radiator, but after that, I'd have to look at it ;-) Sorry....

 

ok, so i think i discovered a leak from one of the hoses goin into my heater core. it will hiss for a while after i turn the car off. Could this be causing me to lose enough pressure for my car to be doing what its doing?

 

Not trying to change the subject, but if a car were to theoretically be missing just ONE fan blade... would that really have such an impact that it causes the car to run hot?

 

it seems like ever since i replaced the thermo, now it just runs hot at idle, and occasionally when u accelerate slowly from a high gear< also, i can crack the cap on my reservoir even if the motor is hot and running, so would this not suggest that im not building pressure?

 

If you can 'crack' or take your cap off of your reservoir when it's hot, and you DON"T hear a hiss, or get burned, your system is not cooling correctly...I'm assuming the hiss is from one of the two hoses that go to the heater core....on the firewall, right behind engine, in middle of car? the left one (when you're looking at it from front of car) is the IN to the heater core, and the right one is the return back to motor....

Missing one fan blade generally wouldn't, but I've seen weird things with 2-3 fan blades missing....it happens...

Thanks.

 

im thinkin thats where the hiss is coming from. and i can smell coolant ever so slightly while im driving. Im gonna try and track down the leak and hopefully that will solve my problem. What are the odds that my water pump is bad?

 

see if it's leaking from the water pump, look straight down behind radiator with a light, and you should see if it's leaking or hear it hissing....depends on the hiss though... how many miles are on it? if your heater core were blocked, you wouldn't have heat....but if you hear a HISS then air is escaping from your system, so that would put a bubble back into the system....an air pocket....

What you need to do, is find that HISS..... I know, sounds ez but isn't....

I'd put a pan under it, and OUT hose on the heater core (the right), careful, it's hot, and see if the flow is good first....or look for the leak....best you can....

 

So i just went to hunt the hiss, and its not there anymore... Its about 72 degrees outside, which is the coolest its been in months and i could not make it run hot while idling, unless i turned the ac on. I also did not smell coolant, nor could i find any leaks. I could still pop the cap off the reservoir without relieving any pressure tho. Both the upper and lower radiator hoses are hot, but i can squeeze them fairly easily so im assuming its not building pressure. When i drove to work this morning, it ran hot every time i would idle, and when i made it to work and parked, it started dripping coolant out the botttom of the reservoir again, even tho the car was at normal operatiing temp when i turned it off. I am completely stumped here as to what the problem is. I thought when a water pump went out, it would cause the vehicle to overheat all the time. Could the pump maybe just be working like halfway? Also, i have about 158k miles

 

welcome to audis....

now we are back to, maybe the system isn't bled correctly.....but like I said earlier, I want you to get it warmed up, put a pan underneath the back of the engine (to catch coolant), when the hood is up, look straight back in the middle of the engine on the firewall, you should SEE two small hoses on the heater core with clamps.....pull the right one off (careful, IT"S HOT), AND just see how much coolant comes out, alot? a little? a trickle?

Let me know...it could be something difficult, or simply just not bled right...but you said you heard a hiss etc and smelled coolant...watch it tomorrow, if the WP is leaking you should be able to see/smell it between the radiator down below....

I will pull some diagrams for the bleeding proceedure for you as well if I have time tonight....

AS I stated way earlier in this post, my thermostat went bad, but since you have to tear the whole thing down ANYWAY, I replaced the Water Pump and the Timing Belt at the same time, and my radiator cores looked fkd so I replaced the radiator as well.....you can buy a whole timing belt kit, from some vendors online, like blauparts or worldpac that are pretty damn good parts and not too spendy...

OR did you get an OEM thermostat, or buy one from an auto parts store??

Did you boil your old one in a pan on the stove and see if it opened?

 

i bought a thermostat from the dealer and spent way too much on it. The old one appeared to be stuck open somewhat and took a long time to react when i held a lighter under it and dropped it in cold water. So i hooked up my car to a computer today, and it ran btw 210 and 212 degrees, no matter if the gauge read right in the center, or at the three quarter mark where it does when it gets "hot". This kinda leads me to believe its a bad sensor. but that doesnt really explain why the coolant drips out of the bottom of my reservoir when i park it sometimes. Is 210 to 212 normal operating temp?