Expansion tank

Looked through past threads and none seem to cover my particular problem. Its a 300TDI and over last few years the temp guage has gone up on the odd long steep hill or heavy sand driving - about 10 times over 30000 miles of thrashing it around. I have always had to put 1/4 litre or a bit more of water in each day to keep level an inch below half way mark. Today I find there is no water in the expansion tank - it is dry. It was last used on a return 30 mile trip for a service. Before that it was driven non stop from southern France a few weeks before. Now the garage says he topped it up. If he did I have a problem. If he did not then it is not as serious. Given that he topped it up and can see no leaks after a trip round the block after refilling has anyone any idea what the problem might be given I leave for Morocco in a few days.

I'd check your P gasket isn't leaking
Its behind the water pump and is the gasket that is between the waterpump housing and the engine block

Here: http://www.landyzone.co.uk/lz/f49/p-gasket-renewal-how-91258.html

plastic tanks also split and leak around the centre seam...

Have the garage pressure test your cooling system to 17psi, and check the condition of the filler cap.

If the spring is on it's way out you will lose coolant.

Hope this helps.

Thanks all. Can't see a leak around the P ring and the plastic tank has recently been replaced - as it split around the joint. Filler cap just screws on and its plastic. Taking it back to the garage tomorrow - 30 mile trip so will see if it loses its water again. If it doesn't it suggests the garage did not top up!. Though still wonder about the gradual loss.

Try warming it up then carefully remove the filler cap to test if it is pressurised. If not then start looking for the leak.

bluehaze said:

Try warming it up then carefully remove the filler cap to test if it is pressurised. If not then start looking for the leak.

Click to expand...

i did that with mine and got champagne out the filler hole lol...

Been to garage - no loss of water - no leaks - drove back round trip of 60 miles - no loss of water - garage insisted water level was topped up!. Looks like will be doing my trip with fingers crossed and a little extra supply of water.

Another place to check is the thermostat housing. Also it may only loose pressure when it gets hot if as said above the cap may be faulty and spring opens too soon. Also check fins on rad as these corrode and slow cooling down especially when under load.

Ok so the latest is that it has been left unused for a few days and checked the level again today. And it has gone down!. Where is the logic in that. Has anyone any more ideas. No leaks can be seen. Setting off tomorrow on a two day 1300 mile drive.

What condition are the pipes in?

As bluehaze said, I would check all of the pipes. It's also worth checking that the jubilee clips are done up tight - I had a tiny water leak which was only noticeable after a couple of weeks...turned out the bottom hose just needed tightening :doh:

We have had a very good look at all pipes, all of which look virtually new. There is absolutely no coroding of the rubber and all the fixing are shiny new looking. Could anythink be leaking internally into the engine although the oil is clean with no foaming.