A4 1.8 Overheating - Help please

[TomPetrilli]

It's a 1999 A4 1.8, 112k miles. The engine has started to run quite hot over the last 2 days, and even got an overheat light on today. Overheating only happens after sustained motorway speeds (I had been driving about 15 miles today when it happened). Slowing to 60mph stopped the overheating.

Upon investigation the coolant in the tank was boiling, the internal heater was working (extremely well), but the radiator was stone cold. Hence my questions:

1) Might this just be an air bubble? If so how do I bleed/drain/refill the radiator/coolant? (never done any DIY maintenance on the A4)

2) If bleeding the radiator doesn't fix it, what else may be the problem, and is there a cheap/easy way to find out?

Many thanks,
Tom.

[gaz A]

Hiya mate, I had the same problem with seat leon 1.8T turned out to be the coolant pump. the little propellor that pushes the coolant around had broken in half so it could only manage to keep it cool at slower speeds. hope that might help.

[nick_a4t]

hi, broken wp impellers are rare, change the thermostat first mate. nick

[ronmcintosh]

Hi easy and cheap one to check is thermostat, at the age and mileage it could well be locked solid. If the whole radiator is stone cold there is no water getting through and the main dam in the system is the thermos. seen it happen to a couple of my mates in the last few years
Ron

[TomPetrilli]

Many thanks for all the tips - did turn out to be the water pump (propellor), now replaced & working.

[gaz A]

Glad you got it sorted mate. How much did id cost? mine cost me £375 and i had a new cambelt put on.

[TomPetrilli]

Mine was £409 including new radiator (had a leak there as well) - from Nationwide Autocentre in Southampton.