Not sure I have a problem, but my engine coolant have been running about 10* - 15* F higher than usual, over the last 6 months (May - October). The car DOES NOT OVERHEAT and has maintained normal coolant levels. The car normally runs 186 -192*F, but I am now seeing 200*F for the past months during normal driving. The maximum temp I have seen in logs while driving is 212* I have made no changes the car over at all except I switched my brand of oil from Castrol to Total Lubricants, and it has been running in it current form for about 4 years. My car is single turbo 500+RWHP occasionally driven on weekends and has all the necessary cooling mods such as KOYO Rad and heat shields. I have checked the usual culprits such as operation of the fans, water pump fins, replaced thermostat, replaced coolant thermo-sensor.

Could it be related to higher ambient temps (GLOBAL WARMING)? Logs for last year summer were checked and the normal operating temps never got quite this high.
Any Ideas guys on what could be causing higher coolant Temps?

 

Do a cooling system pressure test. Could be that one of your hose clamps loosened up somewhere. Also, hose down the fins of the rad and oil coolers in case gunk accumulated there.
Beyond that, I got nothing but higher ambients do usually result in higher cooling temps given that the heat exchangers rely on air to cool the liquids running through them.

 

Thanks for the reply Gracer7. I'll try to do another inspection on my heat exchangers to be certain, but I doubt that that's the cause. The engine compartment is well kept and always clean.

I'm hoping Its related to higher Ambient Temps.

 

If it makes you feel better, when I switched from conventional to synthetic oil my normal water temp actually dropped 2 degrees. So 100% the 2 are related. When was the last time you did a coolant flush? Its possible that it's just the high ambient.

 

I think it's more a cooling system issue. Have you checked your T-stat? When did you last change your coolant. Have you tested your pressure cap? Are you using a different weight engine oil? Have you checked your oil temps?

If you really believe it's related to the incoming air temps, drive around when the ambient temps are the same as when you were reading 186-192. If it's still reading 200+, you have your answer

 

If the AC condenser is in place I've been surprised before at how much crap can accumulate between that and the face of the radiator...just sayin’.

 

Yes, Its the only thing that has changed before the higher temps. Only thing I still use the same weight just a new brand. Didn't think it was a biggie in relation to engine temperature.

 

Thanks for the reply, coolant was changed 1yr ago, same weight oil but different brand. Oil temps also seem higher but I will continue to monitor them.

 

In regards to relationship between the weight of the oil being used and engine temps, does a thicker oil generally yield higher engine temps, or is it the other way around?

 

I would check for obstruction in the air flow path - a bag sucked into the front of the car. Next thing would be a lazy thermostat or a bad cooling fan.

Could also just be the fact that it's been a REALLY damn hot summer.

Dale

 

I'm kinda leaning towards this one. Perhaps in conjunction with the change I made in engine oil brand.

 

Yes, a heavier oil weight will will increase engine temps. Brand shouldn't matter that much (probably more differences with manufactures of synthetic oil)

 

moving or sitting?"

If its higher while sitting, 10/10 its the fans/voltage etc wearing down

if its both sitting and moving, most likely its ambient temps, gunk on the radiator, but could potentially be the tune/timing as well. Are you sure the tune isn't changed at all?

 

Ive noticed when the T-stat wears my temps raise a bit. Possibly it gets gunked up and not opening all the way. Consider changing it and see how it changes.

 

Update: I appears that my higher than usual coolant temperature's were related to the ambient temperature. Now that the ambient temperature is much lower. The coolant temps are now back to the normal levels.
Also, I was recently informed the July 2019 was the hottest on record.
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