typical overheating issues

well, here it goes...i was coming home from Big Bear yesterday, hit san bernadino/riverside/temecula in the heat and it began to get REAL hot. Not a new issues btw. things that are new:

water pump
thermostat
fan clutch
fan shroud
all hoses
radiator
fluids

electric fan was turned on with my bypass switch. i have an additional sensor/switch to control the fan as well. that was on and set to 210. I have done a CO test with the motor running and radiator cap off. no water coming out of the exhaust, no water in oil or oil in water. motor runs fine, plenty of power. vacuum bypass switch for the heater is operating fine. i checked the radiator with an IR gun and my dash sensor is pretty close, only a few deg off

the rig is currently on stock gears (until i'm done with axle swap btw lol) with 35s on a 6" LA kit. no inner fender liners. a little weighed down, but not that bad. it shouldnt be doing what its doing anyways. it does it when its relatively cool out with no rack or crap in the back. i've been considering putting vents in the hood as i think there might be positive air pressure causing the radiator to not get any air flow across it. when i pop the hood its like a darn oven in there.

thoughts? i've searched and searched all over the internets and can't find anything but it seems to be a common issue with these things.

hood standoff or vents will always help but sounds like either an air flow or fluid flow. could be cloged heater core

35 inch tires with 3.55 gearing, I'm surprised your transmission didn't overheat too...
Actually maybe it did and the trans lines that run through the radiator heated the antifreeze.
sounds like everything is spot on except the tire size.
If you have smaller tires, try them first before any motor work.

it did the same with 31s when i got the thing. i know the tires are large, i'm swapping out to full width tons so i'm not messing with the gears. i p**sy foot around town and dont touch OD very often. transmission and top end are freshly rebuilt. i was thinking that about the trans fluid heating up the radiator coolant though...

i was thinking air/water flow but like i said, i replaced all those parts and still no go.

i'm not passing any fluid thru the heater core so not sure what issue that would cause? the valve is funtioning properly and has vacuum going to it.

just paid for this guy over the phone:

http://www.summitracing.com/parts/BMM-70268/

arrives on Weds. Fingers crossed that will get me by until i swap axles.

Looks like my AC condenser was plugged, badly. not passing much, if any air at all. I couldnt tell at a glance but put a drop light and some compressed air at it last night and hardly any light/air was getting thru. She's running much cooler now. wooooo!!

I don't see that you've flushed the system. Has that been done?

At what point did it start overheating? At random? After a particular mod?

Its fixed now, but it had done it since I got it. I flushed the system out.

I'd strongly recommend a trans temp gauge at some point. Until you have one, you can't really tell for sure whether the engine is warming up the trans fluid or vice versa, at least without stopping and opening the hood.

I know. It's also on it's own b&m cooler separate of the radiator. Check out my previous post, I wasn't getting air flow across the radiator. It's fixed now, no overheating issues. Thanks guys

Whoops!!

Shoulda read a little more. My bad

no worries! glad its finally fixed...

bad thermostat #2. replaced this weekend, bought a new one from the stealership....wish me luck. lol

I got my last 2 from O'Reily's, Murray brand, made in Israel, not China. So far so good. They even have the giggler valve built in.

Was it over heating at idle, or when up to speed? That's my issue. Idle is fine.

Giggler valve?

sandsgg said:

Giggler valve?

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JIGGLE PIN

What does a jiggle pin do? It helps bleed the cooling system of trapped air by allowing air to pass into the radiator and released from the system.

These are becoming rare on thermostats. You can duplicate the effect by drilling a small hole in the thermostat flange at a location that clears the gasket mating surface areas.

How's your cat?

mako my day said:

Was it over heating at idle, or when up to speed? That's my issue. Idle is fine.

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well, it was a combo of a stuck open thermostat (two now) and a wildy innacurate temp gauge. IE 230-240 on the gauge = 195 in real life. If i was coasting downhill the temp would drop down to 100 or so on the gauge (whatever that really is in real life..) then if i was going uphill or putting a load on the motor it would sore up to 230-240 (actually 195). then it would take forever to heatup, sometimes it wouldn't, sometimes it would heat up real fast...sometimes if i was at a stop light it would get to 230 (again, actually 195, but didnt know that at the time) and my electric fan controller was trying to compensate all the time. Anyways, i replaced the thermostat with a dealership one with the little valve in it and it heated up to 230 on the dash right away. i about smashed my beer in rage (lol) until the IR gun got fired up and read 195 on the housing. dead on accurate. so yea....all fixed now.

there was other things going on too like a plugged AC condenser that has now been removed, old as balls water pump (replaced), some vacuum lines not routed properly etc etc. those and a lot of other things were fixed a LONG time ago...its been the thermostat/gauge thing that has been driving me crazy. That and lack of time to work on it. Let's just say that the previous owner really neglected the Jeep and did half assed repairs on everything. glad its finally fixed. it was some good closure that i needed badly. Cant say i've ever had this many thermostat/cooling issues before in all my damn life and i've owned well in excess of 40+ cars lol

Ecomike said:

I got my last 2 from O'Reily's, Murray brand, made in Israel, not China. So far so good. They even have the giggler valve built in.

Click to expand...

Isreal thermostat FTMFW!

IslanderOffRoad said:

How's your cat?

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Not sure if you're asking me or not, but its fine.