Signs and syptoms for a head gasket leaking

Hi all

My new purchase (2002 Fiat Doblo 1.9 diesel van) is losing water from the header tank and possibly the rad (can't get to view it as yet) - not too much but annoying. It starts fine and runs sweetly. Left it ticking over and as the temperature built there seemed to be excessive pressure within the header tank causing the loss of water.

I also have the problem of hardly any heat in the cab. (suspect the thermostat has been removed).

If there is a leak on the head gasket am I correct in thinking that it would put pressure into the cooling system causing the blowing out at the header tank?

The oil ways inside the engine (viewed through the filler) are clear of gunge and the oil came out (on changing it)dirty but no sign of any water contamination.

A head gasket leak can cause pressurisation of the water system as you describe. You don't always get contaminated oil. A garage should be able to diagnose the fault with a pressure test.

The head gasket is always the first point of call when there are no obvious signs of leakage.
What exactly do you mean by excessive pressure? As the system warms up it pressurizes normally.
There could be an air lock in the system that's preventing the water from circulating properly or the thermostat could be jammed shut but that wouldn't cause water loss unless it was blowing out the header. Is that what you mean by excessive pressure? Check all the easily fixable things before blaming the Head Gasket. I've seen too many head gaskets replaced and the original problem still being there.
What engine do they use in that wagon? Is it a Citroen/Peugeot or one of their own?

ratm said:

The head gasket is always the first point of call when there are no obvious signs of leakage.
What exactly do you mean by excessive pressure? As the system warms up it pressurizes normally.
There could be an air lock in the system that's preventing the water from circulating properly or the thermostat could be jammed shut but that wouldn't cause water loss unless it was blowing out the header. Is that what you mean by excessive pressure? Check all the easily fixable things before blaming the Head Gasket. I've seen too many head gaskets replaced and the original problem still being there.
What engine do they use in that wagon? Is it a Citroen/Peugeot or one of their own?

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Thanks everyone for the input so far.

When I ran the temperature up to the fan cutting in the return pipe to the header tank was putting so much pressure in to the header that it was lifting the cap and spilling fluid at the cap as well as the return connection. At a guess I suspect that the thermostat has been removed by the previous owner to help mask the head gasket problem - (would appreciate any thoughts on that one). Not sure whose engine it is - not overly powerful at 63 bhp but it seems to be enough for what I want it for. Certainly a cracking seat position for my back with more adjustment than any seat I have sat on before!

So the water is obviously getting hot throughout the system so that rules out a jammed thermostat. How long does it take to heat up? If the thermostat was out it should take a while if the engine was just ticking over. If indeed the thermostat is out and the engine gets very hot quickly it's more than likely a gasket problem. Make sure it's the correct cap that's fitted to the header tank though. If it's rated for a lower pressure system the seal would lift before your system was pressurized. Try running the engine with the header tank cap off and see if you can make out if the water is circulating cold. It should only start circulating fully after the temp gets high enough to open the thermostat. How easy is it to check if the thermostat's in? Some can be a right pig but it would be best to rule that out first.
It's fairly easy for a garage to check using a cooling system pressure testing kit. If in doubt get the mechanic out.