2008 JKU Sahara Overheating
 

This past Monday I was out with 4 other JK's. We were on a trail that isn't difficult, a few hills. There was some snow and ice. About 20 minutes in my Jeep began to run hot, water temp was 3/4 of the way up. I was in 4hi, esp off, OD on. I have since read that 4low and OD off would have been better for temperature issues. The outside temperature was about 2c, or 35f. Speeds no higher than 20km/h. As soon as I got off the trail and onto the highway (110 km/h) temp dropped back to normal. There is not anything on the bumper in front of the grill. Coolant levels look good. Also, when driving in the city, even on a dry day, I notice a large amount of steam coming from under the hood, but at normal temps. What could be causing this?
Thanks in advance.

Have you noticed if your fan is running when the engine is overheating?

Bad cooling at low speed, and good cooling at highway speed, suggests your fan is not coming on.

I also have a 2008 JK. Just before going on vacation, I took mine in for an inspection. They found the water pump was going bad. Since we have the LIFETIME powertrain warranty they did the repair for free. Check your water pump.

Yep, that'd be my guess too.

My 2008 JKU just had a water pump go bad. 44k miles. Replaced under warranty with the "lifetime bumper to bumper warranty" which jeep did in early 2008. Thank goodness I have that too because if not, the ownership of this vehicle would certainly put me in the poorhouse!

Lol:crazyeyes:

Drive around for a bit and park, carefully look if you can see any thing leaking near the water pump, radiator, or if your fans are on.
(Usually if you are leaking coolant, the tempts wouldn't just go down when on the highway creating radiator air flow)

My WP wasn't leaking/dripping... they discovered it when doing a mandatory inspection to keep the Lifetime warranty in tack.

I just replaced my water pump too. They really should last longer than they do..

I have roughly 44K on mine as well. Aside from the water pump and overfilling gas tank thing, my JK has been pretty much trouble free.

Full disclosure, my JK has been relatively problem free as well.

In the 5+ years of ownership I have only had:

Water pump - warranty
Rear carrier & gears - warranty
Wiggity-wack A-pillar rattle - warranty
Throwout Bearing - customer pay :gak:
Clutch, pressure plate & flywheel - customer pay - :gak:


Not too terribly bad. The only vehicle that we've owned that had a better track record was the wife's Toyota Camry


Dodge ram- D44 complete blowout, head cracked both at 55k miles, a really great truck but sold at 98,000 miles
Volvo wagon - holy crap, j u n k ! .? Miles
Toyota Camry - absolutely nothing. Perfect car IMHO 150,000 trouble free miles
VW gti - bought new - tons & tons of leaks, shorts & junky build 114,000 problem filled miles
Saturn LS Wagon - remarkably a very well built car. Never a single issue. Strong V6 24v DOHC. 100,000 miles
GMC Acadia - very well built & engineered. Two steering boxes, a new rack (both under warranty) 77k miles.

These are just the vehicles we have purchased new. I think it's unfair to judge the cars we purchased used in this group.

All things considered, the JK has been a pretty decent little rig. Too bad the TOB, rear diff & water pump all died right around 40k miles...

Mine was getting hot like that and it turned out to be the electric fan.