tescolegs

Can anyone help me? I have recently bought an Audi 80 coupe 2.6 V6. 1996 The car looks absolutely stunning apart from the fact she has an overheating problem. It appears that the water is not fully circulating around the engine which could signal an air lock or blockage. We have changed the radiator, checked the water pump and thermostat, all ok, and we have flushed the system, but still nothing. when the engine is running the top hose pipe to the rad is hot but the bottom one is stone cold. There is also no water running in the hoses that run into the **** pit for the heater. We have been working on this car for a number of hours now and have had all the timing belts off twice. (Not a fun job as anyone else who has done it will know!) Apart from leaving the engine run and taking hose pipes off one by one everywhere to try and find the problem I don't know what else to do. How would this air lock have got into the system? Someone has mentioned about the pan at the bottom of the engine has water flowing thru it and the problem could be there, any ideas guys?

Lago Blue

Yet more burping of air from the system may be required even though it appears full.

There may be two (One on the hose leading to the heater, and one on the pipe across the back of the engine) bleed screws (or one on the cross-tube, and a covered bleed hole (instead of a bleed screw) on the heater pipe at the firewall) that each have their own issues that you should beware of before you touch them, do a search here first. (see illus.).

These engines are famous for being somewhat difficult to fill. Comparing volume removed to volume replaced can also help you diagnose it in case this is -not- your issue.

A search here will reveal many frustrated owners trying to re-fill their system. Pay attention to the particular reservoir fill instructions. I do remember that there is a slight yet important difference between the 12V and 20V owner handbooks here, so what your 2.6 Coupe might have I can only guess. Carry a can of mixed coolant with you and go "burping".

drwg. shown is from 12v.org.

tescolegs

Thanks very much, I guess I'll just percervere. Not aware of the bleed valves on the back, found the one by the back for the heaters, so this may well help.

Cheers

Luxus Panzer

don't touch those bleed valves on the hard pipe, they will snap.

you only need to bleed via the 1 bleed valve on the pipe near the firewall (soft pipe leading to/from the heater core)

Loosen the screw...fill up reservoir and then place lips on reservoir hole and blow!! (cold engine) once you stop getting bubbles via your blow job keep some pressure in the line and close the screw.

if you own a B4 and want to change your coolant, your car will thank you for a blow job.