yvk_99

Today after driving around for an hour...I getout of the car and smell hot coolant.

I peak underneath and I can see fluid dripping near the transmission pan. Maybe near the metallic pipes.

This means the plastic belly pan is dry all the time.

I have been telling the mechanic that I have been losing coolant...but he kept saying pan is dry. He can't see any leak.

Also the coolant smell and leaks are only after driving the car around.

Any input ???

DaveInSaltLake

Pinhole leak that only allows fluid to pass after pressure builds up in the cooling system. Use the fluorescent dye and a black light to find it.

yvk_99

whenever the coolant level is topped between MIN and MAX
and the car is driven around...I can smell coolant outside the car and see it drip next to the transmission fluid pan....after the coolant level has lowered...the leak slows down...

Same with smell,when coolant level has lowered...smell is also less frequent....

DaveInSaltLake

My working assumption is that with the extra air space in the cooling system the pressure does not increase enough to push the coolant out of a pinhole leak or poor hose connection.

In my case, I can see the coolant leaking from the radiator for awhile when it's up to normal operating temp, as you describe, after I top off the coolant reservoir.

Stop leak would likely work for awhile, but I'm hesitant to use that junk in a good Audi motor and cooling system. I'm planning on replacing the radiator soon.

yvk_99

Re: Thnks for replies..no visible coolant drip today only slight smell and level reduction by 1/2 cm