Coolant leak

[gazzy]

Can anyone offer any advice? My 2000 C4 appears to have a coolant leak which drips from behind the nearside silencer,this only occurs after really driving hard and doesn't usually happen during normal runs.I have run my hand around the plastic header tank and this appears to be dry,are there any other leak points in that area? I've tried looking but everything is so packed in I can't see the source.

 

[Bus Boy]

Is there steam coming form the front of the car after a run? Sometimes the radiators perish at the front where leaves get in and rot and corrode the rads. This happened mine. There was no leak in the header tank and the cap on the coolant tank was also fine. I just got the warning light on the dash. I hope it's you don't have to replace the rads, just food for thought Gazzy. HTH. Baz.

 

[Pepi1677]

I had the same on mine, it turned out to be a hairline crack in the header tank. Its a know issue that the plastic gets brittle as it goes through many heat cycles and it sits over the exhaust. When the coolant system is warm and under pressure it opens the hairline crack up, however when cold there is no leak.

 

[Richard_Hamilton]

As David says, it might well be a hairline crack or pinhole in the tank. They seem to do this on the back face, which makes it impossible to see. However, if it is dripping from the drain tube, it might be that the tank cap is leaking (common problem). This then collects in the tray on the top of the tank, and drains down the tube.

 

[gazzy]

Thanks for the replies,I haven't noticed any steam from the front and they looked ok when I cleaned them but I will keep an eye on it.I take the point about the header tank sealing as it cools down,by the time I've managed to run my hand round it it has cooled a bit.I'll probably start with the cap and then change the tank,looks like an a**e of a job,anyone done it?Again thanks for the replies,always nice to know if somebody else has had the same problem.