Over heating diesel
 

Hi ..diesel ...runs normal temp around town ..soon as i go up hill ..car overheats !.and starts rattling ! ..which stops as car cools down ...any ideas??
Fan works ok ...no bubbles in header tank ..tho bottom hose dosnt seem to get hot ..unlike top hose ...

Hi.

Over eating owner!
I also get hot going uphill.
Bottom hose also been known to get hot in certain circumstances. :}

It could be a faulty thermostat or other part of the cooling system preventing the correct coolant flow when hot, especially as the bottom hose is notably cooler


Does the noise sound more like a crackling sound than a rattle? you can get this noise when due to insufficient cooling, or sluggish coolant flow, when the coolant reaches the hottest parts of the head, which will be hotter than normal, it forms ' steam ' bubbles, this steam bubble quickly reverts back to water due to the bubble moving through the cooler coolant and the coolant being under pressure.


There will be no bubbles seen in the coolant when this happens.


When it's doing it you should also be able to feel the pulses in the top hose with engine off if you're quick.

certainly a rattle !..

yep sounds like me too ...tho bottom hose soft and limp !!

Does the heater work if set on full heat? last time i had one do this the impeller had fallen off the water pump

Yes heater works fine ..

It's almost certainly your thermostat stuck or not opening fully Chris. They're known to be unreliable on the diesel.

Simon

Hi Chris.
You say the fan is working have you done the demist test? also as above the original thermostats on the diesel tend to open slowly, so maybe it's not fully open when you go up hill, how far have you travelled to the said hill or is it all hills even if you have been driving for an hour or more?

Hello there ..thanks all for helpful replies ..Arctic ...demist test ????think i had done approx 10-15 miles ..its all hills around here !!! ..diesel tourer i had previously was exact opposite ..ran really cold til i did thermostat in top hose trick ...temp gauge rises to half way and stays there til i up a bl**dy hill !! i then have to put heater on full to help cool it ..fan comes on ok ..also starts rattling too ( water pump impeller ?)...its not losing or using coolant ..nearest 75 guy cant look at it til mid june ..