Hi all,
Having some recent issues with an occassional over temp problem. After casual cruising at highway speeds followed by stop/start city driving, I find the temp gauge occassionally almost in the red zone. It happens very quickly and then after driving again at 60 kph all things come back to normal. Day can be hot as (40 degs) or raining (18 degs) makes almost no difference.
Took the car into STI@Docklands and they ran it on a dyno under load, found some air pockets in the cooling system, bled them out and then all seemed ok. Within a week, I noticed it starting to happen again on a mild wet day (last Friday in Melbourne).
Back to STI again today and they did manage to see the same symptoms I described (that it happens quickly, then goes away). The mechanics indicated they should just change the thermostat and flush the radiator, but the technical guru at STI (Steve) discarded that solution because of the characteristics underwhich the over temp occurs.
I tend to agree with him. If the thermostat was crook, then I should see longer lasting over temperature situations. If it was a radiator blockage, then similarly, the over temp would not be fast and intermittent.
STI indicated it would most likely be a head gasket Hard to say precisely which bank, but given that the 3.0R utilises a metal head gasket, a crack between exhaust and compression chamber may expand enough to open up after some high thermal load and then close up again after the vehicle get back in motion with the more efficent cooling.
So, not being a mechanical engineer (other than many weekends spent with my dad in my formative years pulling down engines and gearboxes and helping with re-builds), I am open to suggestions or experiences pertaining to the sources of overheating on the 3.0R.
Also, any recommendations for head work if they do need to come off. STI maybe on the expensive side and I know there are some good specialists in Melbourne, just not sure if they have experience with the 3.0R.
Mark.