Hood Vents - do they work??
 

i take the family out on occasion and they like the air conditioning, which can overheat the jeep on long climbs or when slow moving. To quantify what i mean by overheating it does not get real hot just goes slightly above 210 and maybe will climb a hair more but since the needle is moving in the wrong direction it makes me uncomfortable so i shut down the air. i have been thinking about installing some hood vents to keep the motor cool so i can continue running the air for the family. do they make a difference in reducing engine temps or should i focus in another area?

I would flush the coolant system to make sure its clean,If that don't fix it try adding some water wetter that stuff can drop your temp about 20 degrees.

Did you ever make any decision? I like the idea of the vents, and it cant possibly hurt anything. If you're on Instagram check out @daddy_fox1 He recently installed some VOLVO Semi Truck Hood Vents on his ZJ, and they turned out SICK. And their on AMAZON for only $75

I have not installed the vents. I had read that the vents dont do anything significant to reduce temps after posting the question. I thought about vents+oil cooler with fan (plumbed into the oil filter) but at that point the system becomes too complicated and invites failure.

i did add some water wetter but could not tell the difference. My thoughts at this point are to install a larger radiator but i think it will have to be custom made as i dont see any larger ones for sale on ebay or Amazon.

I wouldn't imagine that hood vents really ever make a major difference, but in a high load condition, at low speeds (crawling), it should do something to allow more heat to dissipate.

There is a little bit of a science to venting hoods besides just punching holes in them. If you want maximum cooling on the highway, you need to vent the hood where there is a vacuum so engine compartment air is pulled out. Where most people vent hoods is a neutral place or a place if high pressure, which will not help you on the highway. The place of vacuum is where the air breaks over the hood. Back by the windshield is a high pressure area which is why muscle cars used to draw air for a carbureted engine there. They could get a little more air at speed and a few extra ponies. These are the only pics I can find of mine today for some reason. But this is the position to use. Do they work, oh yes. Sprung a coolant leak one time and watched the air/coolant flow up out of the vent. Sucked it about six inches up before splattering my windshield really quick so bad I couldn't see.

Was about to do this on my JK, never thought about the WJ. Subbed...

So did you eventually do the vents or how did you fix your issue?
I already bought the vents on amazon. I am planing on putting a scoop over the vents as it rains heavily 8 months a year where I live, so I do not want water to go in the engine bay.

I never did install hood vents. Since this post my radiator plastic blew and I replaced the radiator with an aftermarket alum radiator. that radiator along with the electric Taurus fan that I have on there seems to keep it cool enough. There's maybe only one or two occasions since when I had to turn off the AC due to the temps starting to climb.

Well i do not have any issues with overheating when the AC is off, it actually hardly goes over 200 but when I turn on the AC it can climb up to 230 which is not that bat after all, but my main concern is all the plastic inside that is going to wear out because of the heat.
I will be putting a Flow Kooler water pump and installing the hood vents next week, so the vents should help to extract the heat out of the engine bay as well as keeping the engine temp a bit lower.

I would be really interested to hear how the flow kooler water pump works for you. Seems like it will help while at lower rpms.

Yes, I will try first the pump without the vents to see if it improves or what and then i will do the vents and will keep you posted.

I used AC floor registers on my last XJ. Looked alright, the faded hood paint distracted from the vents haha. I ran them further torwards the rear but it was more for low speed venting than high speed venting. If I went back to do it again I'd turn them 90 degrees and mount them further to the front where the lower pressure area is at as stated above.

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