Hi Guys. I am still having problems with an overheating TD5 Discovery. Things done so far Bled the system thoroughly, completely removed thermostat to allow freeflow of water, New expansion tank cap and finally today tried to check water pump but not to sure what I have found. \with bleed screw removed and expansion tank in its normal position all I got was a steady trickle of water but not sure what to expect help please
 
Why have you removed the thermostat? Its there for a reason. Put it back (make sure its working first)

With the cap off, engine cool (obviously!) start it up... any bubbles in the expansion bottle?
 
Why have you removed the thermostat? Its there for a reason. Put it back (make sure its working first)

With the cap off, engine cool (obviously!) start it up... any bubbles in the expansion bottle?
It has been a process of elimination so far. I had an idea the thermostat was sticking so removed it from the housing to take away that questionmark. with the cap off and engine cool I saw no noticeable bubbles in the expansion tank but I did get some small amount coming through the bleed hole. By the way I have a new thermostat ready to go on.
 
If your getting a stream of water coming out of the feed into the expansion tank id be happy with the water pump.

When is it over heating? Have you got a nanocom or something similar so you can monitor the actual temp rather than using the gauge? The gauge works in a weird way and doesnt really tell you wants going on.

Is the cap leaking? Have you pressure tested the system at all? Sniffed the expansion tank for exhaust gases? losing coolant? is it a properly mixed ratio of coolant. oil in the coolant at all?

Need more info to assist really.
 
My old cap was leaking hence the replacement no oil in coolant or vice versa no sign of "mayonnaise" at all and as far as I can tell no smell of exhaust gas. I take it the feed in to the expansion tank you refer to is the small return pipe from the radiator? I can not say I noticed any flow coming back in through there at all. I was losing coolant before changing the cap but that has stopped now. The only time it shows as getting hot is on uphill grades and then this causes the engine to de rate. If I sit and tick over for a few mins temp will drop to normal and full power returns. I have no way of measuring temp other than the temp gauge.
 
are you sure your not loosing coolant , ie a full system will overflow if bleed screw is removed with engine off,does rad get hot all over
 
Rad not feeling like it gets overly hot anywhere and engine does not have that red hot smell. And the only time anything comes out of the overflow is when I lift the expansion tank above the level of the overflow.
 
it is in the outlet on the head for the top hose ,its hard to be certain about our issue without actually seeing it ,but worth a try before head gasket or water pump change
 
It is easy to fit the thermostat the wrong way round on the V8, possible on the TD5 as well ?

Peter
 

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