Coolant

[Doyt W. Echelberger]

Hello Max,

My 87 5ktq just displayed similar behavior, and this time it was a failing 
heater valve.... the valve was new about 4 years ago.  The dripping coolant 
ran down onto the catalytic converter and boiled on the hot surface, 
creating the cloud of steam. So...............check out that valve on your 
car.  The valve already failed and got replaced on most of the 
remaining  5ktq's, so yours would be in good company.

The heater valve is a round thing about the size of a silver dollar, in a 
heater core line between the engine and the firewall, about a foot and a 
half above the catalytic converter. The originals were plastic and tended 
to develop cracks with age, so I put on a metal one in 2002, and it 
lasted  4 years. Go figure.

In June 2002 I got the metal replacement from an Autozone store in Ohio. It 
was in a box with titled  "Factory Air Part # 74671,  Heater Valve. 
All-metal."  $18.99 plus tax.  They are a little more than that now.

That is probably more information than you want.....but the steam cloud may 
be from a failing heater valve.

And here is more information.......My other difficult-to-find coolant leak 
was the small/short/tiny coolant line from the cylinder head water entry to 
the pipe passing round the front of the engine to the turbo. Nasty spot to 
get at with any kind of tool or clamp. Many 200's failed at the same place. 
....people ended up replacing heads. You don't want this to happen to your 
car unexpectedly.  My 87 leaked from a short rubberized fabric section 
where it exits the engine. Your 86 may be different and even more 
vulnerable if it has a water-cooled turbo.
    This is what Fred Munro says to 86 owners:
            "Ouch! '86 owners, watch the pipe as well - it is galvanized 
steel and rusts
            out. In '87, the metal pipe was changed to stainless.     Fred 
Munro  '94 S4"


Doyt Echelberger

 >>>>>>>>>>>>>>>>>>>>>>>>>
At 03:22 PM 12/8/2006, you wrote:
>Hello all,
>
>I have a 1986 Audi Quattro, type 44, every 3 months/2,000 km. I have to 
>fill in about 500 ml. of antifreeze into reservoir, the red warning light 
>with thermometer symbol blinks and makes a noise at first, then just 
>blinks and disappears. When the car is idling I notice some steam rising 
>from front left of car. Notice nothing conspicuous under hood. The car 
>performs well.
>
>Max