HG is the common one and can have odd and sneaky symptoms in early stages.
You want rule out basics of water flow from things like thermostat, rad core, water pump rotor etc, cooling system wants pressure testing and chemical test during a hot run .
check plug colour, check bottom join of head to block for any signs of leak issue gunge along the join.
We get quite a few that pass gas sniff test and chemical test but it the HG and time proves it if nothing else can .
I'm considering starting an independent Subaru garage, I've had too many questionable experiences with main dealers. I'm sure with a Haynes manual and a set of spanners I could be as competent. After my wiring harness I was hearing a strange intake noise when over half throttle. Opened the bonnet and went digging around to find the clamp on the intake to the intercooler completely undone! Lucky it's been so snowy here I've hardly needed to put my foot down.
Im hoping someone can maybe shed some light on my situation that ive lived with for months.
Ive a 2.5 Hawkeye 2007. My car overheats badly, it forces me to pullover wherever i am, switch the engine off and once cooled, top up with water. Ive discovered a pattern, it seems that the car will over heat when I'm pushing it, driving hard, OR, driving at a constant speed of 80mph ish..
I had someone say that it was my head gasket but ive checked for hydrocarbons and I'm confident its not that. Im now struggling to figure out the issue.. is it radiator related? Thermostat?
When Its overheating, ill switch the engine off, but keep ignition on, I can hear the fans kick in until it reaches usual temp.
Any info on this would be greatly appreciated.
thank you !!