Hi All,
Having a very inconsistent overheating issue with my '95 turbo 1hz. My experience so far is overheating after a while (hour+) of driving when slowing back down to city speeds from highway driving. The temps will shoot up when stopped or crawling but will suddenly drop all the way below operating temp almost at random. Once it begins the overheating process the temps won't stop spiking unless I keep the revs high when driving, same goes for once I'm back up to highway speeds in keeping higher rpm keeps the engine cool.
So far I've replaced the thermostat which was faulty and sticking. This has helped noticeably but the problem is still there. I've ordered a new fan clutch which I suspect is the reason for the engine stays cool at high rpms so fingers crossed that's the only issue.
My question is what are the chances that it's a head/gasket issue. Coolant is dumping into the overflow but only to a point but I'm not sure if that's to do with overheating, the radiator cap or that I've been mostly using distilled water until I'm confident it's fixed. No other obvious head issue symptoms, EGTs never really get above 400c, running a factory 1hd ct26 at 17psi.
My thoughts are that if it were a head/gasket issue it would be worse by now as it's done a few, unfortunately mandatory, highway runs and a significant amount of kms since the issues started. Haven't felt any performance drops either, still rips around town.
Having a very inconsistent overheating issue with my '95 turbo 1hz. My experience so far is overheating after a while (hour+) of driving when slowing back down to city speeds from highway driving. The temps will shoot up when stopped or crawling but will suddenly drop all the way below operating temp almost at random. Once it begins the overheating process the temps won't stop spiking unless I keep the revs high when driving, same goes for once I'm back up to highway speeds in keeping higher rpm keeps the engine cool.
So far I've replaced the thermostat which was faulty and sticking. This has helped noticeably but the problem is still there. I've ordered a new fan clutch which I suspect is the reason for the engine stays cool at high rpms so fingers crossed that's the only issue.
My question is what are the chances that it's a head/gasket issue. Coolant is dumping into the overflow but only to a point but I'm not sure if that's to do with overheating, the radiator cap or that I've been mostly using distilled water until I'm confident it's fixed. No other obvious head issue symptoms, EGTs never really get above 400c, running a factory 1hd ct26 at 17psi.
My thoughts are that if it were a head/gasket issue it would be worse by now as it's done a few, unfortunately mandatory, highway runs and a significant amount of kms since the issues started. Haven't felt any performance drops either, still rips around town.