Cooling Issues

[scrimple101]

Well i've tried everything. Radiator professionally flushed and cleaned, new thermostat, water pump impellor perfect, changed fan over. And still the engine is overheating. The strange thing is that the fluid in the radiator is cool. Could there be a blockage somewhere in the water jacket?

Regards, Rob.

[Wacky Dee]

once the car warms up .. is the top radiator hose hot ? It should be .. Is the bottom radiator hose only warm (not hot like the top one) ?? The bottom hose should only be warm if it's hot then your radiator is not doing its job

The factory water temperature sensor is at the top radiator hose (water exiting the engine) so if it's reporting the engine is overheating the top hose should be HOT which is normal ..

You could also have air stuck in the cooling system so bleed it ... best way to do it, 2l coke bottle shove it into the radiator cap seal the joint so coolant doesnt leak and then poor coolant into bottle (obviously cut the bottom of the bottle off) let it run for about 30 mins ..all the air will come out the radiator cap and you will see big ass bubbles in the bottle with the coolant

[mad082]

you have said that the water pump impellor is perfect, but how is the housing? if the housing is a bit worn and the impellor isn't making a tight seal then it won't pump any (or enough) to cool the system properly (had this problem with my outboard. the impellor was new but it wasn't pumping water at idle and only a little bit at full speed because of the housing being worn). if you don't know how old the water pump is then i would replace it to be safe.

also, when the radiator was professionally fluched/cleaned, did they actually open it up and clean it, or just flush it?

for the fluid in the radiator to be cool while the car overheats means that there is a flow issue, whether it be the thermostat not opening properly (you didn't install it the wrong way did you?), the water pump or a blockage or air leak.

as wacky dee said, the top hose should be hot. if it isn't and you are still getting overheating issues then there are a few things to do. first (this only applies if you have a stock ecu and are going off the temp gauge in the dash saying the car is overheating) is to get a hold of a consult cable so you can see what the ecu is reading the temp as. it reads from a different temp sender to the dash, so if it is reading ok then you just have a faulty temp sender. however if it is reading hot as well as the dash but the coolant/hose is still cool, then i'd say the thermostat is a probable suspect as it will be letting out a very small amount of coolant (enough to alter the temp sensor reading) but not enough to actually heat up the radiator

[Jmaac]

Is it overheating or is it just the gauge? Check the sensor and associated circuit

[Moodles2]

Times like this you really need a consult cable to check what the ECU reports the water temp as.