200tdi overheating - Part 2 (I think!)

dodgy sender switch?

Your water pump theory sounds plausible. If the bearings fail then you would expect to see water dribbling out of the little hole in the underside of housing, but it has been reported that the impeller can become corroded/fall off such that no water gets pumped.

Richard

How can I check the water pump? Presumably it is just a case of taking the top hose off the radiator (giving it to someone else to hold) while I turn the engine over! - If it throws water out then its good I presume??

I suspect these things either work or they dont, with no in-between?

Thanks jon

Feeling for pressure in the top hose after the thermostat has opened also tells you that water is on the move (It warms up quite quickly once the thermostat opens and pressurises noticably).

Thats difficult to say - if the corroded impellor story is true (I've not seen one) then they can half-work!

Richard

Ok, so I suspect I should replace the top and bottom hoses and possibly sender unit first.

Whilst the top hose is off, take out thermostat and check to see if the pump is pumping.

Then, fail in all that do the Head Gasket.

Does this sound like a sensible approach??

Thanks Jon

If you have a local garage that can test emissions for a blown head gasket that would perhaps be a better bet, at least to start with.

Richard

I didnt know this was possisble. Good idea. I will investigate local garages. Jon

Ok, I had another better look last night and I fel a bit of a fool...

After my adventures at Driffield the other weekend I pressure washed the front of the radiator (after remoiving the grill). I assumed that the pressure washer would remove ALL the crud from between the cooing fins from front to back - BIG mistake!

Whilst the front of my radiator looks like new the rear looks like a mud wall and I suspect my immediate problem!

Tonight I will remove the cowling, intercooler (cos thats crudded up too) and top hose and get the pressure washer around the back.

This should then revert my temperature back to running hot rather than too hot. Then at the weekend its off to the local garage to get a gas and pressure test done of the head because I would like to see it running at 1/2 temperature rather than 3/4.

I'll let you all know how it goes.

Thanks Jon