OK here it goes, 90 TT Auto (bog standard), drives fine, does not overheat but stop the car, turn it off and low and behold it will leak coolant!

 

Tried flushing the system for air locks. Compression is OK on all six. If the car runs off boost it will run all day quite happy - BUT give it full boost and it will start to dump coolant. Help I'm getting depressed.

This is not totally unknown, although I've not heard of it on a Zed. Basically, the cooling system is working when you are moving and when you stop the latent heat within the engine causes the system to increase in temp and pressure then boil over. So you could have a little split which opens up under pressure or the rad cap could be the wrong pressure or have a weak spring.

 

Does the electric fan work ? If the temp sensor is working then I think this should run on when you stop the engine. Do you have access to a Consult or Techtom for checking the water temp, it is normally around 80-84 deg C when running.

 

[This message has been edited by AndyP (edited 27-11-2001).]

Makes sense, yes the fan does continue to run if its really hot but it normally dumps coolant even thought the engine is not hot enough for the fan to kick in. I guess I must have a leak under pressure or could it be a faulty water pump?

Thanx Andy,

 

Yep the fan does run on, but it dumps coolant even if its not that hot, like you say I must have a leak under pressure somewhere, I presume as it runs ok without overheating it couldn't be the water pump?

could just be the radiater cap. Mine does it every now and then if i release the pressure ont he cap it seems to stop doing it for a long time,

maby also a leaking coolant filler.

Sounds similar to my symptoms. Got the water pump replaced and it seems OK now (touch wood).

 

Where (under the car) does the leak appear to be coming from. If it's towards the back of the engine (drivers side) it could well be the pump.

Uh ? Water pump is at the front of the engine.

Oops - sorry, meant front.

No wonder mine was knackered (joke!)

 

I'll now leave any technical replies to the experts! (LOL)

Thanxs guys,

 

I'll try the pump first, 70 quids better than 300+ for the rad.

 

Hears hoping

 

Roy