Acceptable Coolant Temperatures - help required
Submitted: Sunday, Jan 17, 2010 at 16:58
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Hi all.
I am looking for a bit of advise regarding acceptable coolant temperatures.
Situation:
I am running a 98 Hilux 3 litre 5L diesel with an aftermarket axt water cooled turbo charger. I have a digital temperature sensor that has a coolant temperature sensor in the top radiator hose.
Problem:
On a hot day (30+ degrees) , and travelling at high speed (100 - 110 km/h) with the air conditioninng on my coolant in the top radiator hose sits between 95 and 100 degrees celcius. With the air con off 93 - 95 degrees celcius. This only occurs during high speed driving. Normal city driving or idling the car sits on 88 - 89 degrees celcius (the rating of the thermostat). If my car is overheating and I pull over on the highway the car will cool to this temperature very quickly. Driving at 110km/h the turbo boost sits on approx 5.5 psi.
What I have tried to bring down my coolant temps:
The viscous fan appears to be working fine.
I got it Dyno tuned and the boost turned down to 9 and the fueling tuned last week.
I have tried a new 88 degree thermostat just to be safe
I have added redline water wetter.
The previous owner put in a new radiator which looks to be in very good condition - it is now about 18 months and 10 000 kms old.
I have a thermo fan the helps cool the car at idle speed.
I have taken
the spot lights off the car to increase airflow
How you can help me:
1) What is an acceptable temperature for coolant running through my top radiator hose? (am I being too picky - can i run hotter temps)
2) What can I do to achieve a satisfactory coolant temperature.
Thanks for any help you can give me.
Dan
Reply By: Ozhumvee - Sunday, Jan 17, 2010 at 17:34
Sunday, Jan 17, 2010 at 17:34
Make sure the coolant mix is at the MINIMUM ratio as specified by Toyota for your ambient temperature.
Too much coolant WILL make it run hotter than it should as coolant doesn't conduct heat as
well as straight water.
The water wetter will make a few degrees difference but will not compensate for problems.
Do you have an external oil cooler? Fitting one will increase oil capacity slightly and also cool the oil which will remove heat from the engine. If you do fit one don't put it in front of the radiator/a/c condenser as it will cause airflow restrictions and pump heat back into them negating any advantages, try to mount it either below or beside the radiator, if necessary with its own fan.
Basically your problem is that the engine through turbocharging is creating more heat, more power = more heat so to get it to run at the non turbo temps you have to either increase the cooling capacity or its efficiency, or lift the right foot!
Your temps don't sound excessive but different engines run at different temps.
For example the Chev V8 diesel in my Humvee has a thermostat that opens at 90 C the engine is quite happy in the 90- 110 C range and any hotter than that is cause for concern with my engine.
My troopy with 2H a/c on and 35 c day would struggle to stay cool in 5th on the highway at 100kph, drop back to 4th and back to 95k and it would run all day with no problems due to the fact that in 4th the engine was spinning faster, oil and coolant is being circulated faster and removing heat from the engine better.
It may be that you may ahve to get used to travelling slower in hot weather ;-))
AnswerID:
399886
Reply By: JAZZY - Monday, Jan 18, 2010 at 09:35
Monday, Jan 18, 2010 at 09:35
I work for a radiator/air conditioning
shop. Why don't you take it to a local radiator
shop and have it all checked out? Why risk cooking your engine?
They will completely
check out your cooling system, including thermostat, radiator & water pump as
well as the fans and give you a diagonisis for FREE.
A lot of radiators look "new" but I have seen a lot that have blockages and need to be replaced. They are manufactured in China these days so don't last as long as they used to.
AnswerID:
399972