2.5V6 coolant and fan woes

Lord of Hog · 17th August 2016, 06:34

I assume your engine really was totally cold when you removed the filler cap? They retain heat for a ridiculous length of time. Remember that you've got an expansion tank rather than just a simple header so, assuming your cap seals correctly, any warmth in the coolant circuit is going to produce enough pressure to give a little hiss when you unscrew the top. I agree with Kaiser about the fan though: as long as it's spinning it shouldn't contribute to any overheat.

Air locks are very common on the KV6 if it hasn't been re-filled exactly as per the approved MG method, and even when it has it often takes another few days of checking and topping up to get it absolutely right. Otherwise, as I discovered on mine, one or two very small leaks (particularly in difficult-to-see places close to warm items) can give the impression of one big one.

17th August 2016, 06:34	#11
Lord of Hog Gets stuck in Rover 75 2.5 V6 in Wedgwood Blue Join Date: Dec 2015 Location: Felbridge, East Grinstead Posts: 982 Thanks: 250 Thanked 294 Times in 206 Posts	I assume your engine really was totally cold when you removed the filler cap? They retain heat for a ridiculous length of time. Remember that you've got an expansion tank rather than just a simple header so, assuming your cap seals correctly, any warmth in the coolant circuit is going to produce enough pressure to give a little hiss when you unscrew the top. I agree with Kaiser about the fan though: as long as it's spinning it shouldn't contribute to any overheat. Air locks are very common on the KV6 if it hasn't been re-filled exactly as per the approved MG method, and even when it has it often takes another few days of checking and topping up to get it absolutely right. Otherwise, as I discovered on mine, one or two very small leaks (particularly in difficult-to-see places close to warm items) can give the impression of one big one. __________________ Conformity is not morality. Consensus is not truth.