What can I try doing next to cool this 4.7HO down?

WJIN4LO

New member
So I find when it gets hot outside and especially on a mountain pass it gets bloody hot, yesterday I measured temps using my ODB2 reader and found the following:

1. Outside in the 70s a nice cool 193 on the highway and will go up to around 203 with the air-conditioner on.
2. Outside in the high 70s/80s running around 205ish without air-conditioner and around 213 or so with it on.
3. Outside in the high 80s/90s running around 215 and was creeping to 220 with the air-conditioner running.
4. Outside in the 90s on a winding mountain road going uphill I was hitting 230+ (forget the air-conditioner at this point), but as soon as I start going down hill again temps drop fast.

So far I had my mechanics check the radiator flow and to check my thermostat wasn't sticking and everything was fine there according to them, I have a larger aluminium radiator and an electric fan, and in traffic it does not get hot.

Does anyone have any bright ideas as to where to look next? the engine is not that old (<25k miles and came from powertrain products).
 
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When mine did that a couple of years ago in the mountains, it was a bad fan clutch. Do you have any mechanical fan at all? Does your water pump have threads on the end where you could add one? I know some people have done that.
 
What coolant are you running? Could add water wetter or engine ice. I've seen guys setup an intercooler sprayer to help cool the radiator for when they're pushing it hard. What size fans do you have on it now? Can you get bigger ones? What about your trans cooler is it part of the radiator or have its own?


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When mine did that a couple of years ago in the mountains, it was a bad fan clutch. Do you have any mechanical fan at all? Does your water pump have threads on the end where you could add one? I know some people have done that.

I have only an electric fan, however when it gets hot I am moving at speed so I assume the fan would not even help, especially in my other case when sitting on 70 MPH on the highway and it gets to 220 that points to me that it would not be a fan issue at all as it is getting more than enough air flow, it seems to me as ambient goes up temps go up, and with load they go up even more.
 
What coolant are you running? Could add water wetter or engine ice. I've seen guys setup an intercooler sprayer to help cool the radiator for when they're pushing it hard. What size fans do you have on it now? Can you get bigger ones? What about your trans cooler is it part of the radiator or have its own?


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I am not sure what they ran in the coolant it was recently flushed though. I have one large electric fan (am going to have to go double check what size it is) and the trans cooler is separate.
 
Have you tried blowing high pressure air or water through the radiator from the back or engine side? May think it won't matter, but I had any overheating problem in a 379 peterbuilt. The truck was washed regularly by me, and I always pressure washed the radiator. A mechanic took a high pressure air hose and hit it from the engine side. It looked like a dust storm in the shop. After that no more overheating. Just a thought and cheap thing to try if you go through a lot of dusty areas. May not do any good, but can't hurt to try

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Have you tried blowing high pressure air or water through the radiator from the back or engine side? May think it won't matter, but I had any overheating problem in a 379 peterbuilt. The truck was washed regularly by me, and I always pressure washed the radiator. A mechanic took a high pressure air hose and hit it from the engine side. It looked like a dust storm in the shop. After that no more overheating. Just a thought and cheap thing to try if you go through a lot of dusty areas. May not do any good, but can't hurt to try

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I will give it a go thanks, it can't hurt!

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Automatic transmission? If so, does the transmission cooling line run through the radiator? My 99 XJ would overheat frequently when climbing trails or grades because the transmission fluid was getting hot and subsequently heating up the coolant. Since I dont live in a cold climate I decided to bypass the radiator all together and run a B&M transmission cooler. The only reason the transmission runs through the radiator is to warm up the fluid when it's cold, which is something I don't need where I live. Hope that helps...
 
What yr wj do u have? The reason i ask is as far as i know all 4.7HO came with a hyd fan that is run by the power steering pump
 
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