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View Full Version : WTF why the overheating?!?



x1n54n3x
06-23-2009, 04:35 PM
on the way to work this morning, the coolant temp shot up for some reason...
i had figured maybe the level was a bit low so after work i stopped by a friends shop and he topped me off. after that on the drive home, same thing happened along with the oil temp which peaked at about 250*. when i rolled into my driveway, i popped the hood and i could see the coolant bubbling inside the reservoir, and it looked like it was trying to get through the thin hose on the left. almost like there was a vacuum or a blockage that was preventing the coolant from circulating. anyone have any ideas? it was running fine yesterday, in fact i made a 60 mile round trip without a single problem, the coolant temp didnt even hit the center marker on the gauge. unfortunately i have to go back to work at 5, but its only a couple minutes from home. ill have access to the forums from there. I have a vagcom i can use, would i be able to check anything with it? help![headbang]

this is honestly one more thing to add to the shitlist my car has offered in the past couple months. (bad coil in #1, battery took a shit, AC mysteriously ceased to work, headlight went out) FML

audimike18t
06-23-2009, 06:48 PM
thermostat?

dcampana
06-23-2009, 06:58 PM
coolant temp sensor?

Jibberific
06-23-2009, 06:59 PM
I think you have the wrong coolant in there. You are only supposed to use the audi brand G12 coolant, if you use the other shit it will cause problems. Pretty sure it starts to solidify after a while...

That's why if you look on the reservoir it says "G12! --->" with the arrow pointing to the cap

Dynamite
06-23-2009, 07:46 PM
thermostat or maybe water pump.
change the coolant with the correct coolant but flush through with water 1st. when you are doing this take your thermostat out and check if it is working, at the same time if water is not coming out of the whole where the thermostat was then a line is clogged.
if the line is fine and the thermostat is fine then it is probably your pump.

x1n54n3x
06-23-2009, 08:19 PM
A) come on, do you really think i would put the wrong coolant?? thanks for the suggestion though.
b) the water pump and thermostat were replaced less than a thousand miles ago (TB replacement)
c) i thought it could just be a sensor, except for the fact the coolant is physically gargling in the reservoir, it hasnt done this before today, which is why im thinking something could be clogging a hose. anyone had any issues with a clogged coolant hose? how the fuck does a coolant hose get clogged? it only has 94K, so its not like the rubber is deteriorating (shit, i hope not.)

spyder101
06-23-2009, 08:47 PM
Is the lower radiator hose hot at operating temperature? If it is is the viscous fan engaging?

x1n54n3x
06-23-2009, 08:56 PM
i'll have to check after i got off, i know the upper hose was hot as shit though.

njm23
06-23-2009, 09:02 PM
You keep driving ti like that (overheating coolant and oil) and your going to have more problems than you could imagine. I would still question the thermostat regardless. And the upper hose is always hot as shit, anything with coolant in it after the car was run to operating temp will be hot as shit.

If you think there is something clogged in one of the jackets or lines, try doing a flush on the system, should clean anything out.

hernandez3011
06-23-2009, 09:30 PM
My car started overheating 1 month ago and it turned out to be a jacked up water pump...the plastic impeller was literally split in half. It's Strange that it would overheat and considering you just replaced the water pump and t-stat. I have never heard of a bad CTS showing high temps on the gauge.....in all cases I personally have experience with, the gauge/needle shows cold or fluctuating.

Be careful though; when my water pump messed up, my t-stat was only 2 months old. The extreme hot temps can ruin your t-stat and cause it to stick shut. Keep an eye on that.....squeeze the lower hose going from the rad to your engine. It should not be hard to squeeze if the car is warm.

bassed
06-24-2009, 08:20 AM
Check Water Pump
Check all coolant lines
Flush Radiator and start with new coolant. 50/50 G12 and Distilled, not 100% G12!!
T-Stat - replace
Coolant Temp Sensor - replace

Don Supreme
06-24-2009, 08:29 AM
Check Water Pump
Check all coolant lines
Flush Radiator and start with new coolant. 50/50 G12 and Distilled, not 100% G12!!
T-Stat - replace
Coolant Temp Sensor - replace

can't stay away huh?

dcampana
06-24-2009, 10:28 AM
^^^lol.. glad to see he's still helping out

markcm
06-24-2009, 12:07 PM
Is the lower radiator hose hot at operating temperature? If it is is the viscous fan engaging?

Good points here, my A6 had about 50k on the full TB service with pump and thermostat... when it overheated (boiled over). Fan wasn't comming on either. I wasn't sure if the pump and t-stat got done at this last service so I figured it was one of them. Turned out the pump was good as new (metal impeller and all), bad thermostat. Stupid how all the water systems are behind the TB, I ended up doing it all including cam tensioner seals since I was in there and had 50k since the last service....all for a t-stat. with a buddy deal on the labor this turned out to be a $700 t-stat replacemet; least i'm good to go for a while (and the cam seals were leaking pretty bad)

spyder101
06-24-2009, 06:34 PM
funny that this topic came up. My Audi over heated this past saturday and I was'nt too thrilled about it, to say the least. I checked the upper hose, it was hot...lower was'nt. Viscous fan was not engaging because, the coolant was not hot enough inside the radiator to make it work. I then pulled the thermostate out, stuck it in a pot of boiling water and it opened up, so I last checked the impeller through the thermostat housing and found that it had came apart as well as spinning freely on the the shaft. New water pump fixed the issue. fucking plastic impellers...

x1n54n3x
06-24-2009, 08:34 PM
thanks everyone, as of now its sitting in the warehouse i work at. schedules stacked until tomorrow so it's just going to chill for a bit. tomorrow after work i'll have a chance to see whats up.

bassed
06-25-2009, 12:45 PM
can't stay away huh?
[>_<] It'll be hard to walk away all together...

^^^lol.. glad to see he's still helping out
Grassyass

thenofjboy
06-25-2009, 02:45 PM
Check Water Pump
Check all coolant lines
Flush Radiator and start with new coolant. 50/50 G12 and Distilled, not 100% G12!!
T-Stat - replace
Coolant Temp Sensor - replace

damn - ive been toping mine off with mine off with straight G12, i guess that ok.

but ill be flushing my system next week & replacing some odds & ends. I thought G12 came mixed but i was wrong!!

what "would" happen if somone was to use 100% G12??

somebody5788
06-25-2009, 03:40 PM
I would find out if you got another plastic impellar water pump or if you upgraded to a metal one. If it's the crappy plastic one then I would def suspect it.

B5A4Kevin
06-26-2009, 06:42 AM
what "would" happen if somone was to use 100% G12??

less efficient heat transfer.

InTTruder
06-26-2009, 07:18 AM
Impeller is the most likely cause. Diesel Geek kit FTW. Mixed coolanbt will gel, not materially affect heat removal capacity in and off itself, unless the gel clogs passages.