1998 audi a4 1.9tdi murky coolant.

[carlover]

hi all, im not new on her ive just forgot my old username and password ! doh.
any way i have bought the said car and have noticed the coolant has slight black water in the expansion tank, there doesnt seem to be any sludge just black murky water.
the engine oil is good with no sign of water in whatsoever.
does anyone know what the problem might be ?
im going to give it a engine oil and filter change and coolant flush in the morning.
is there a guide anywhere do completely drain all the coolant out of this engine ?
ive bought a haynes manual on ebay but it has not arrived yet.

[BrandonA4]

Hi there draining the coolant is pretty strait forward remove the front right lower vent on the bumper and you can push on a hose to direct the coolant into a catch container and there should be a RED drain tap just unscrew that to drain your system. Also unscrew the expansion tank cap and pull back the heater hose so the bleed hole is exposed, not sure what engine you have but on my 2.6 V6 ABC motor there is also another bleed hole on the line under the expansion tank going back to the motor, an Allen key screw if i remember.

[carlover]

thanks very much, to refill should i just pour the coolant/water into the expansion tank or is there a bleed technique ?

[BrandonA4]

Yes there is a procedure make sure the bleed hole near the heater core is open when filling the expansion tank and when coolant starts coming out of the hole push the hose back on and then repeat with the second bleed hole under the expansion tank going to the back of the motor.

[Big Skinny]

Hi I have an Audi 2.6 V6 cabriolet which is in pretty good shape however i noticed that there is a black substance in the header tank and its starting to over heat , i have changed the oil cooler and coolant (G12+) and after 500 miles its appeared again any ideas ?????

[Big Skinny]

ps it does'nt look or feel like oil more like soot !!!!!