strange overheating

sadlotus · Apr 7, 2010

Hi all,
I've had a 94 disco 200dti for a few months now - 190000 miles all seems ok - had a bit of welding done recently for the MOT.

Yesterday was on the M11 and temp guage went up to the stop and red light came on.
Let it cool for half hour then continued.

10 miles on at destination -
Top hose hot and small hoses from waterpump - hot.
Bottom hose, rad, expansion bottle - cold.
plenty of water, heater works
Smells hot.
I'm thinking it could be:
the waterpump?
or a stuck thermostat?
collapsed bottom hose?
fan mechanism?

suggestions please.

Paul

Ahaggar · Apr 7, 2010

my money is on the waterpump!

mjltigger · Apr 7, 2010

not sure if the heater would still be any good without a pump.. I'd test the stat first..

sadlotus · Apr 9, 2010

Well done the man who said thermostat.

I had a sleepless night thinking it was the pump but decided the easiest job was the thermostat. Picture below shows what I found - the rod thingy had punched through the 'bridge' thingy and popped the 'washer' thingy off the bottom. luckily I was able to fish that out of the bottom of the stat housing (hoped there wasn't a spring too!).
Never seen this happen before.
Did 200 miles today with no stat - read somewhere not to do that but not really much choice - car ran perfectly, new one goes in tomorrow.

Mate said the reason it happened is written on the side........FRANCE

jonathanp · Apr 9, 2010

What you have there with that broken thermostat is a situation where the coolant will bypass the radiator and mainly flow around the engine as when cold and when hot some coolant will still by pass the radiator , hence overheating . Regards Jonathan

sadlotus · Apr 9, 2010

Yes, thanks Jonathan, it also flows through the heater matrix so having the heater fan blow did help a bit.

jonathanp · Apr 9, 2010

Yes , when overheating one of the best things you can do is have the heater on full blast , I have discovered it makes a big difference to cooling as it takes heat directly from the engine block,in fact when the car is sat idling when hot and the heater on full I can tell the difference between the heater inlet and outlet pipes and you can watch the temp guage go down . Regards Jonathan

strange overheating

sadlotus

New Member

Ahaggar

Active Member

mjltigger

New Member

sadlotus

New Member

Attachments

jonathanp

Active Member

sadlotus

New Member

jonathanp

Active Member

Similar threads