p38 overheat

1999 p38 2.5dse over heated in the matter of mins only to blow a big crack in top of rad!! any body have any ideas how this may have been cause! ive got the rad out and the thermostat seems to be opening! pump seems to be pumping! so im kinda stumped! help needed

James

Sounds very very familiar, EXACTLY the same thing happened to me, result was a cracked cylinder head.

Mine happened as I was driving along on a daul carriageway, came off at the junction, parked up in a village and as I got out saw lots of steam and smell of coolant coming from the engine bay, saw this below...




My specialist said to me after it happened, sometimes it can be a cracked cylinder head, sometimes it can just be an old/weak radiator. The choise is yours I guess, try replacing the rad and then keep your eye glued to the temp gauge and see what happens, you might be lucky. If you go this route make sure to get out regularly and check the pressure of the coolant pipes, if you cant squeeze them (and you properly bled the cooling system) then you probably have a cracked cylinder head with gases escaping into the cooling system pressurising everything and risking the split rad again.

A sniff test did NOT reveal a cracked cylinder head on my DSE because the crack would only open up at high engine temps, specifically for me, coming back along the M40 from Oxford to the M40/A43 junction, its a sort of long incline, this would cause the crack to open and things to overheat pretty rapidly.

-Wills

it happened just after start up so was cold! went bout 3/4 of mile across the farm and whoose up temp looked under bonnet to find big crack on to of rad!

james84 said:

it happened just after start up so was cold! went bout 3/4 of mile across the farm and whoose up temp looked under bonnet to find big crack on to of rad!

Click to expand...

I would try a new rad then, you will need one anyway and once that is fitted sniff test it. From what you say, if it failed that quick after start-up then it either pressurised really quickly meaning the head is cracked or the head gasket has failed - the test should show it.

Are you sure the rad didn't fail the last time you used it and you just didn't notice it??

-Wills

no the rad was fine! as i check all my oil and stuff etc..