dayday

I have a 2004 jeep grand cherokee that's been overheating while on idle or stop and go. Has 85,000 miles. My thermostat was recently replaced for the same problem but now it's reoccuring.

Any help? Thanks!

trucker

Could be the thermostat again, clogged radiator, bad water pump or could be your radiator cap. The cap have valve on spring. Gently pull the valve with fingernail and relise. If the spring work then look for other problems. I saw many bad radiator caps. Buying new one does not mean that the valve works. I would recommend getting manual temp. gauge as the electric do not show correct temperature. If goes too high, at most cases, it is too late and the head gasket will be damage. Check the oil.

ol"blue

The 4.7L V8 has an air bleed near the top rad hose that needs to be opened when re-filling the system to get rid of any air pockets behind the thermostat. This may/may not be your problem.
Dan

Justin93

Water pump is screwed. mine broke and over heated when idleing

1ATony

The water pumps in these things go like candy. can you see antifreeze dripping from the pump at all?

Also is the fluid runnin low in the radiator at all?

ol"blue

I've never had an overheating or water pump issue with the 4.7L V8 in my '04 WJ. Granted, it's only got 88,000 miles but still. We've towed a trailer from Tenn. to Mich. and had no issues since new. Maybe we just got lucky?
Dan

dayday

I figured out it was my radiator. I replaced it and now my jeep isn't overheating! Thanks for all your help!!!

ol"blue

Well I'm glad you got it figured out and fixed.
Dan

TheCoroner

My jeep is a 99 4.7l v8. I replaced the thermostat 2 times new rad 2 times the stock one lost the drain plug and the second one was cracked on the radiator filler neck. The heat has never worked the car has over 110,000 miles on it. I started work right before it started to get REAL cold november early december, and i was running straight water so before it was cold enough to freese i drained it all and removed the radiator, how ever while i was doing other work i noticed that the thermostat was frozen in a block on ice inside the housing. I thought nothing of it and refilled the system and let it warm up, it got to operating temperature and stabilized about 20 degreese over 210 then if you take it out and drive or leave it idle too long it overheats. Ive had people tell me its the heatercore thats clogged and causing restriction in the system, i just dont think that would be an issue if it has never worked before. So i replaced the thermostat again and it did the same exact thing so i bled it, and bled it and bled it and still noting, so its sat since early december. I realy need my truck back for work and this snow so any sugestions i am eager to hear. The only things on the cooling system i havent changed for new parts are the upper and lower hoses because they are still good and the water pump other than that everything is new. A little side note as well i noticed that when i was bleeding the system after i had the bleeder screw opened and closed many many times it started to seep out of the threaded bore between the bleeder screw housing and the bleeder screw.

Again any help is useful! thank you.

grenade252

mine does it too. could be a number of things. i wired the fan straight to the battery and found it doesn't work.

ol"blue

First, Welcome to CF.
As for the heat not working read/try this:>http://www.wjjeeps.com/hvac_sub_assembly.htm
Since you had ice around the t-stat you might want to check the water pump also. It might have been damaged by freezing water in the block.
As for the seeping around the bleed plug, try using some thread sealer on the plug. It should stop the seepage.
Good luck, and keep us posted.
Dan

Matty13198

My 2004 Grand Cherokee SE 4.7 is acting up. It's been a great vehicle that my wife and I have had for 8 years now and (since its paid off) we want to keep it for another 8.

Just recently the check engine light came on and my mechanic hooked it up to the computer and two codes popped up: oil switch and #4 cylinder misfiring. He reset the computer and said if I'm not feeling any bucking or anything, don't worry about it. Well, I'm not worried abou that (but advice is welcomed). My big problem seems to be with the engine fan. Its making a lot of noise while at idle (and when I hit the gas). The engine heats up while sitting still but once I start driving it cools right back down in to "normal" temps. Then I slow down and the temp climbs again.

Thoughts? Advice? Ideas?

Thanks!

Matt
91 Wrangler - Sold
97 Grand Cherokee Ltd - Sold
04 Grand Cherokee 5.7
Looking for a wood paneled wagoneer...

ol"blue

Welcome to CF. I'm assuming yours has the engine driven fan, as does my '04. The issue with your cooling fan could be engine mount related. A bad/broken mount can let the engine sag enough to let the fan make contact with the shroud. To check this, open the hood w/the engine running. Set e. brake, put it in drive. Hold the brake with left foot and briefly give it some gas to see if the engine lifts excessively, and if the fan makes more noise.. That would indicate a bad mount.
The fan hitting the shroud could be slowing it down enough to cause it to decrease cooling air flow through the radiator. It cools down while driving because more air is being forced through the radiator. As you slow down, the air flow decreases, and the temp increases.