Probably not - it only overheats when you use the air con and otherwise it is sitting in the middle of the temperature gauge?
No - I'm not using the aircon at all. It seems to be overheating after the engine warms up and if I push it a little. Otherwise, it seems like if I drive gingerly it's fine.
Have you checked that the air con fans are cutting in? You say they run continuously - that sounds like a short as they should be temperature dependent - they should also keep running when the motor is turned off for a while. Is the a/c compressor clutch cutting in and out? If it's running continuously it could load up the motor.
I will double-check this, it's been awhile since I've been looking at the fans, but from memory, the twin condenser fans run continuously, and the VC fan does seem to kick in with temp, but then it never seems to have the resistance that others have explained to me, whether hot or cold engine.
I would have thought that with a slipped liner/head gasket problem the cooling system would pressurise even if it was cold - I think the pressure you are describing is just from heating up.
Yes, that's pretty close to what it seems like.
One thing's for sure, if you keep boiling it you will end up with a slipped liner, so keep an eye on it and think about how much you need the aircon.
Good to know. I think I might just start on the front brakes (which I need to do anyway) since I have the parts. I've just finished the rears. After all are done that should tick off the dragging brakes possibility. But I don't think this is it – you'd think I'd have some smoke or something if that were the case. I don't want to damage an engine that's already tired, so I'll take my time with this diagnosis before driving much.
After I blew the upper rad hose I replaced it with a new one. When doing the TPS last night I noticed a few hoses that look really tired and are definitely due for replacement. I might just have a look at some hose sets for the coolant system...
I would go back around the basics:
Check hoses for blockages, crimps etc
Flush the radiator
Check the coolant level
check the fan/s operation
Check the thermostat
Check the fan belt
Check the water pump
Clean out the radiator fins
Dragging brakes
crook temperature gauge
Timing incorrect
- hose blockages & crimps: yes, worth checking. I'll add those to my list.
- coolant level: lost a bit when I replaced the thermostat recently, will double check & re-bleed.
- fan/s operation: will double check to confirm what's happening
- thermostat: just replaced with a new one a few days ago. Still overheating.
- fan belt: how do I check this?
- water pump: been on my list to look at. How do I check this?
- radiator: had compression check & flush and they told me it looked brand new, about 50 miles ago
- dragging brakes: maybe. Will remedy either way soon enough
- crook temp gauge: really?
- timing: yep. Will grab a timing gun. It's about time. (See what I did there?)
Thanks so much for all your help john & everyone. It's very much appreciated.