V8growler

Hi everyone. sorry I only seem to get in contact when I have a problem... must write a thread about my A8 trip down through France to the wine country earlier in the year....

Just found this thread via search, has it been resolved? Swede Pete's "Coolant disappears"

Last week I noticed my temp was a little high, not very hot just not as it usually is at 90 degrees. When I got home I checked the level and found the expansion tank empty. Not sure how long it had been low/empty. Topped it up (a kettle and a half did it, whatever measurement that equates to) and everything is back to normal. I've checked the oil for water, sat underneath the car whilst it is at temperature with the under-tray removed, waiting to get wet.... Nothing. The water level appears to be holding steady since, but where did the coolant go? I'll watch it carefully over the next weeks to see what happens.

Is your problem found/fixed yet Swede Pete?

Rob Ad

Water pump?

V8growler

Possibly, although I've never had one leak then not (that I can see). Can't see any dripping or weeping whatsoever. If it is the pump, I'm sure it will get worst, until it poors out all the time.... I'll notice it for sure then.

tonypai

Is the expansion tank or a hose cracked and the coolant is evaporating?

TimD

Probably the oil cooler pipe problem..

V8growler

Oil cooler pipe problem? Ummmmm

PaulW

I have a similar problem, just fill it once every three months or so until I find it

airbil

Check the link below.
This goofy leak seems to only happen when the car is parked after a drive. Could leave coolant under the passenger side or just evaporate I think.
I've had this issue for a while now and the repair parts sit on my shelf waiting for warmer weather. And; while there's an occaison puddle under the car coolant level seems to always be adequate. (Immaculate coolant regeneration?)
OTOH it could be a worn out head gasket which would leave a brownish gunk type residue on the inside of the oil filler cap.
HTH<ul><li><a href="http://www.audipages.com/Tech_Articles/enginemechanical/oilcoolerremovalreinstall.html">oil cooler repair</a></li></ul>

Swede Pete

Yes found the leak. It was the famous plastic pipe between the engine block and the oilcooler.
Used the instructions from Pauls Audipages, worked like a charm.
On my car there was no sign of the leak at all, not a dripp on the bellypan or nothing. So when i started to do the job it was with mixed feelings.
I did a thourly search before i started tough. I took a sample from the oil in the tranny to se if it was leaking in coolant to the tranny. I let about 3dl out and poured it in to a bootle. Then it has to rest for a couple of days to se if there is coolant in there. The water will seperate from the oil and end up at the bottom of the bootle. If there is coolant there it will look like a grey/brown area. Clearly not the same colour as the tranny oil.
Also i took a sample of the coolant from the expansion tank. Did the same thing and checked for oil, if there is oil it will show up on the surface of the coolant, you will se few oily spots on the surface. Also these will show up in a dark brown/grey colour. Can be hard to see. The easiest way to see oil is to slighty tilt the bottle slowly and then tilt it back checking for a thin surface of oil on the wall of the bootle.
Next thing that i did was to bring it to a shop and they did a emmission test in the expansion tank. They put the messuring unit inside the tank (above the surface) and then coverd the hole. If there is a leek in one of the cylinder heads it will most definitly show up on the emission meter. Mine had no leaks.
After those tests i went ahead and did the oilcooler thing....

Peter

V8growler

Thanks everyone for your responses, I'll keep an eye on it and investigate everything before embarking on the oil cooler pipe...