overheating, hood vent, airflow...........

Ok I’m still worried about my overheating issue, so I’ve been searching and reading all I can on hood vents. It seems that there is still a lot of debate as to whether this helps or not and where they should be placed. The one thing there seems to be a consensus on is that it will certainly help the under hood temp, and that sure can’t hurt. The one thing that dawned on me was a lot of the people who are having OH problems had after market bumpers on (at least those that had photo’s) the obvious thing is that some including myself have winches or light bars or whatever that might hinder air flow, but the thing I’m noticing is that most of us removed the bottom air diverter for ground clearance. So I’m going to try something tell me if my logic is wrong, (I’m sure someone will whether I ask them to or not ). I’m going to install some sort of air deflector on the bottom something that can be put on and taken off quickly and raise the back off the hood an inch. This seems at least in my farm boy brain that it would really help the air flow through the engine camber. I should mention the only time I’m getting hot is on long highway hills while towing, I’ve replaced everything in the coolant system and just replaced the fan clutch.

I’m running 4:56’s with 33’s and I’m sick of watching old stock xj’s fly by me while towing what looks to be more then I am while I’m on the side of the road watching coolant blow past my radiator cap

If you want air to escape the engine bay, put the vents in the hood more towards the front and facing rearward. Check out the hood of an 03/04 Mustang Cobra. Air comes in the grille, goes through the radiator, then escapes through the hood to keep the underhood temps down.

If you want cooler air to go in the engine bay other than through the radiator, put the vents towards the back of the hood facing the rear. This creates a cowl intake effect when at speed, but will also let hot air vent out when at low speed or sitting still.

I'll eventually be putting my vents at the back of the hood.

Thanks guys, I read the go jeep stuff which is why I'm going to do the hood lift because it will work like a cowl and if I don't like it or it doesn't work I can remove it.

I guess my question is: If I can get air coming up from the bottom and do the hood lift which if I understand correctly will also suck air in at speed, will they cancel each other out and just leave me with a silly looking jeep on the side of the road watching coolent blow pass my rad cap?

Have you ever had any tranny problems? When I broke my tranny bellhousing out in Moab (in 01), I egged out the torque converter gear that engages the pump. I never knew that it happened, but my Jeep always ran hotter after the bellhousing was replaced. It turned out that this egged out gear was creating too much heat in the tranny and tranny fluid. The tranny fluid runs through the radiator, and this made the radiator hotter. I didn't find this out until my front pump seal blew on the way to PAP (in 03). I replaced the pump seal, put in a different torque converter and the Jeep has run at the correct temps ever since.

I had replaced pretty much everything in my cooling system too, then found out it wasn't the engine cooling system creating all the heat.

A.

Andy in Pa. said:

Have you ever had any tranny problems? When I broke my tranny bellhousing out in Moab (in 01), I egged out the torque converter gear that engages the pump. I never knew that it happened, but my Jeep always ran hotter after the bellhousing was replaced. It turned out that this egged out gear was creating too much heat in the tranny and tranny fluid. The tranny fluid runs through the radiator, and this made the radiator hotter. I didn't find this out until my front pump seal blew on the way to PAP (in 03). I replaced the pump seal, put in a different torque converter and the Jeep has run at the correct temps ever since.

I had replaced pretty much everything in my cooling system too, then found out it wasn't the engine cooling system creating all the heat.

A.

Click to expand...

thx Andy,

I don't think I've had any tranny trouble but I didn't rule it out so I installed a tranny cooler. It doesn't seem to sliping and the fluid looks ok, but what would be the best way to check this.

gabe4 said:

thx Andy,

I don't think I've had any tranny trouble but I didn't rule it out so I installed a tranny cooler. It doesn't seem to sliping and the fluid looks ok, but what would be the best way to check this.

Click to expand...

Put a tranny temp gauge in and see how hot the fluid is getting.

A.

any know what is standard operating temps for the aw4?

Don't quote me, but I think a trans is supposed to run somewhere between 150-180*. I've got a trans cooler and temp gauge and the highest I've seen since the cooler install was 170, which was in traffic on the highway when it was 80+ degrees out. Even towing a wave runner with 32's on stock gears, it only goes up to 150*.

sunburned said:

Don't quote me, but I think a trans is supposed to run somewhere between 150-180*. I've got a trans cooler and temp gauge and the highest I've seen since the cooler install was 170, which was in traffic on the highway when it was 80+ degrees out. Even towing a wave runner with 32's on stock gears, it only goes up to 150*.

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thanks

I've always had issues with my jeep overheating. It's never gotten into the red, but it's been close... I've replaced everything that there is. Radiator (twice), Water pump, thermostat, thermostat housing, hoses, etc. Added a B&M Transmission Cooler, and raised the hood (cheap test to see if it reduced temps (not enough to really tell).

I have not replaced the senor or the gauges, so I have always wondered how accurate they even are? So I am right now considering buying a new Transmission & Water temp gauge.

So have you replaced your water temp gauge? Or do you at least know it's some-what accurate?

I used to have major issues overheating, but with a new radiatior a few years ago and hood vents i have ever only been in the upper half of my gauge twice! thats in two years! when the engine gets warm (closed loop) you can watch the heat flow up out of the vents whenever you are stopped.

IMO vents look 10x better than hinge spacers, but somtimes you just got to do whats free

Tenny said:

So have you replaced your water temp gauge? Or do you at least know it's some-what accurate?

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I haven't and don't, but it really seems to come on quick, which could be the gage just not giving me the right reading. I'll be running along at 210-220 then bam the gauge is pegged and by the time I get the hood open coolent is blowing past the cap.

Don't think its a temp sensor issue if you have coolant erupting out of the radiator. I'd definitely try to find some cheap vents and get them in the hood somewhere, plus replace the thermostat, t-stat housing and whatever else you can.

oh wow, i must have totally missed the fact it it was coming from the radiator cap...

out of ideas on my side then

funny thing ,, i replaced my bumper a couple of months ago and imediatley noticed a differance.. the floor on the passenger side was almost hot enough to melt shoes.. yes i need a new cat .. i knew that already but removing the factory bumper and air dam completly changes the flow of air under the vehicle .. i have also read it in several places about removing the splash gard or not and there is somthing to be said about how that affects the flow of air as well.. im gonna try to build a new slpash gard from aluminium and am leaning towards a cowl hood.. oh yeah a new exhaust and headers and... and.. and....i need more money

have you thought about looking into coolant flow restrictors?The idea is that the restrictor slows down the coolant flow therefore keeping it in the radiator longer.....making the coolant cooler as it goes back into the engine.
Just a thought.....

Manual aux. fan engagement.
Does aux. fan come on?

How's your coolant mix? 50/50%
Which t-stat temp are you running?
You say everything replaced, even radiator? 1,2, or 3 row?
Undo sensor drop it in some HOT water and use a digital thermometer to cross check accuracy of sensor and guage.

Harlee&Tahoe said:

Manual aux. fan engagement.
Does aux. fan come on?

How's your coolant mix? 50/50%
Which t-stat temp are you running?
You say everything replaced, even radiator? 1,2, or 3 row?
Undo sensor drop it in some HOT water and use a digital thermometer to cross check accuracy of sensor and guage.

Click to expand...

Yep I replaced everything with new stock parts
The aux fan works and I just replaced the fan clutch, I haven't had a chance to test whether or not the new fan clutch has helped since I just did that a couple weeks back and haven't yet towed with it yet.