Firebird1

I have a 1.8L petrol Mondeo 2002 which has done 80K miles. The problem which has just started, is that after a run, there is a small patch of coolant on the drive. This coolant is coming from the overflow channel in the expansion tank. The amount of coolant loss is so far not high.
There have been several suggestions that 1. the head gasket maybe starting to break down, 2. the water pump maybe faulty, 3. the expansion tank maybe faulty, 4. the expansion tank's pressurised cap maybe faulty. The running temperature is normal.
I have replaced the cap which seems to have reduced but not eliminated the coolant overflow. I am thinking about changing the tank next, although I can't see anything wrong with it but maybe the cap is not making a good seal. Do you think that it could be either the head gasket or water pump, or something else?

JonathanJ

replace the cap first , cheap and could well be the cause

tabetha

Check your de-gas pipe is clear, as these block easy, esp the restrictor in the tank stub.
tabetha

Firebird1

Thanks tabetha--I am not sure what you mean, can you plse explain further. What's the de-gas pipe?

martysmartie

iTrader: (1)

The de-gas pipe is the thin hose that comes from the expansion tank.

Martin

Firebird1

Thanks Martin. The expansion tank has 3 pipes connected to it. One larger one from the tank bottom which will be the main feed to the engine, & 2 smaller pipes at the top of the tank, From memory, I think that one goes to the radiator, the other I'm not sure. Are you suggesting that one of these smaller pipes might be blocked?