Ever since I got the truck here in the UAE I've been battling with high coolant temps. The first thing I did was install a lower temp thermostat (160F vs 200F OEM) which helped considerably. I would be able to maintain 165F to 185F at night depending on driving conditions.
Unfortunately, it would still eventually reach over 205F if driven in +95F weather and with the AC on it would reach close to 210F. Turns out I had too much freon in the AC system which created a lot of heat in the condenser. Lowered the freon and temps dropped to 200F at noon.
I almost had no high temps after that except when I went into boost or let the truck idle for over 15 minutes. If my coolant temp was 185F it would shoot to over 205F in a few seconds under boost. (See first video)
So what I did was remove the 2 16" spal fans and their shroud. They have served me well since 2012 but they simply restrict airflow at anything above 50mph.
I went with a Bosch fan out of a Mercedes that has an 850 watt or a little over 1hp motor. This single fan is able to flow over 5000 cfm. With much less of a shroud, I could see the engine through the grill now. I had much improved cooling above 50mph. Cruising at noon in 105F degree weather I had no problem maintaining coolant temps of around 185F.
At wide open throttle it has improved significantly, temps are cooler before going WOT resulting in cooler temps overall and as soon as I let off it would drop down to the initial temp in a matter of seconds. (See second video)
Now only one issue remains. I let the truck run for 45 minutes at noon (100F) with AC on. I came out and coolant temp was almost 205F. Which isn't overheating per say but still means my cooling system isn't capable of dropping temps at a stop. Taking it for a quick 5 minute drive dropped temps to 190F. This is not due to the smaller shroud as it was still doing the same with the spal fans setup.
I'm thinking with twin turbos both heating up the oil and with my oil cooler being separated from my radiator unlike stock with no fan or airflow, my guess is that the oil temp gets extremely hot at a stop. My next plan is to add a fan to my huge Setrab oil cooler. Probably one of the two spal fans I took off. I know I can do better because my friend with a single turbo is running the factory oil cooling system and is able to maintain sub 170 degrees in traffic with the same koyo radiator, electric fan and shroud. I will try to add an oil temp sensor as well if I have any room for additional sensors on the Haltech.
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