Club 80-90 Forums

Hi everyone,

I have a 1.9 DG wbx engine in my van. today all of a sudden it overheated. the guage moved quickly over to the right despite my going 60 down a dual carriageway!

when i pulled over and looked at the engine the cap on the header tank was leaking water out of the sides and after further investigation it looks as if the bottle is distorted so the caps not sealing. lots of bubbling too. only one half of the rad was hot!

My question is, could the loss of pressure in the system and leaking cap put air into the system causing an air blockage? could my overheating issue be down to this?

Cheers Rob

loss of pressure would cause the coolant to "boil" and without enough coolant to propel the water pump would struggle to circulate the coolant.

wrobstar21 wrote:only one half of the rad was hot!

That certainly won't have helped - sounds like your rad's blocked. Has it been evenly warm in the recent past? When was the coolant last changed? Is the area of the rad around the fan switch part of the hot or cold bit?

If the fan switch area's cold, and the rad's half-blocked, then your cooling system's going to be struggling to dissipate the heat, and there's no way that the fan can help it. So the temperature's going to rise. If the tank's nearing the end of it's days, then raising the temperature will hasten the tank's demise. As soon as that tank starts to distort, it will, as Kev says, allow the pressure to be released. Basic physics says that the boiling point of any liquid is raised as pressure increases, so once that let go, the boil-over would be almost guaranteed.

Hi, thanks for the replies.

Ive just ordered a new header tank, new coolant fan switch (after testing it works at both speeds), a new temp gauge sensor and a new pressure cap. Ill flush the rad and hopefully if its blocked it might shift it. I did notice alot of sediment looking stuff in the expansion tank after it had all cooled so ill flush the system too.

Hopefully it will sort it!

Tip = whilst you have drained out the coolant, look around the top lip of the engine bay for the thin metal or plastic coolant "bleed ring" pipe. Undo any/all pipes that connect to it and test that thin pipe is not blocked any where along it's length, especially at the "T" pieces, by simply blowing down the pipes.

Reason = that pipe and the associated other thin pipes that connect to it can get bunged up with crud (you mentioned crud ). This can cause a lack of flow around the heads (assuming WBX engine) especially the left one. This causes the coolant to boil, raising the pressure faster than the "dalek" coolant cap can cope with. This causes coolant to be ejected, can distort the header thank and cause burst coolant pipes. Obviously air then gets in and can cause big air locks. Also the lack of flow around that left hand head can cause severe overheating and major damage. Ask me how I know all this Thankfully that was a few years ago now, but I have seen it recently on another van, and read about it more than once on here !

Of course I am not saying that is your problem, could be a blocked rad, but it is defo worth checking those thin pipes while you are "in there"