I'm not dumb. Jeep Overheats / Belt problem

Tiny
JIMKAWA2001
  • MEMBER
  • JEEP CHEROKEE
Ok, I might have several unrelated problems or all of these things might be part of the same problem. About a month ago, my wife was driving her '90 Cherokee Sport (4L in-line 6 w/ 168K mi) when the power steering and A/C went out, it then began to over heat. When I got to her, I found that the serpentine belt had come off. Seemed a bit odd to just have it fall off but I thought that would explain everything. I sent her home in my car and went to an auto parts store to get a new belt (it was worn anyway). When trying to install it, I found that I had almost 2 1/2 inches too much slack, even after adjusting the tension as far as it would go @ the power steering pump. I am SURE that I had the right belt (compared # to the original that came off) and I'm also SURE that I had the belt on correctly. After consulting a professional mechanic friend, he said the quick fix was a smaller belt. I used a belt 3 sizes smaller (seems like way too much) and it seemed to do the trick. I did
check all the pulleys and they appear to be fine. The Jeep would still overheat though. I found that the coolant bottle was cracked and replaced it along with the thermostat (195) for good measure. Now, on the open road or in cool weather, it is fine, runs cool with no problems. In traffic (the stop and go 5pm kind) you have to have the heat on full blast to keep it out of the red zone (overheat). This is no way for the wife and kids to live. I know this is a closed system, can it be flushed? I was thinking new radiator but that is an expensive guess to not be very sure. Are these things related or am I just having a run of bad luck.

I have asked several mechanics and have been told that I don't know how to put the belt on. They say I must have it on wrong and that would account for all the problems. I have been told that this is the ONLY answer to my problem. I know how to follow a diagram, I'm not dumb. I've checked this over literally hundreds of times and have had other people look as well. The belt (all be it the smaller one) is on and routed properly. PLEASE help before this drives me INSANE!

Jim K
Orlando, FL
Do you
have the same problem?
Yes
No
Wednesday, July 11th, 2007 AT 5:21 PM

9 Replies

Tiny
LEB
  • MEMBER
I bet dollars to donuts that your problem is the harmonic balancer.

My son's 6L4.0 had a similar problem while he was on a trip. He bought the belt, and low and behold it was too big. He then pulled it into town and looked at it very closely. There he noticed that the harmonic balancer was *GONE*. Looking more closely, he found parts of it in the engine compartment. We don't know if the belt broke first, or the balancer.

Check that, and I think you'll find the problem.
Was this
answer
helpful?
Yes
No
Wednesday, July 11th, 2007 AT 5:57 PM
Tiny
JIMKAWA2001
  • MEMBER
Would that explain the over heating as well?
Was this
answer
helpful?
Yes
No
Wednesday, July 11th, 2007 AT 6:29 PM
Tiny
LEB
  • MEMBER
Doesn't sound logical, but you have start with something.
Was this
answer
helpful?
Yes
No
Wednesday, July 11th, 2007 AT 6:32 PM
Tiny
JIMKAWA2001
  • MEMBER
Wouldn't the lack of a harmonic balancer change the way the Jeep runs? Other than the smaller belt and the running hot in traffic, it runs the same as ever. There is no more or less vibration or anythign like that.
Was this
answer
helpful?
Yes
No
Wednesday, July 11th, 2007 AT 6:46 PM
Tiny
MERLIN2021
  • EXPERT
If the harmonic balance was missing the engine might jumop around a bit if it's out of balance.
If the jeep have a clutch fan the clutch part is bad! If it's electrical fan try a new temperature sensor.
Was this
answer
helpful?
Yes
No
Wednesday, July 11th, 2007 AT 7:05 PM
Tiny
JIMKAWA2001
  • MEMBER
It sounds like I have 2 issues. If the motor is not jumping, I guess the harmonic balancer (or lack there of) should be alright for now. I need to focus on the heat issue then.

It has electric fan and it runs as it should. Could the initial overheating have caused a blockage of crud in the radiator? If so, can this closed system be flushed or am I looking at a new radiator (might be the best answer anyway?)
Was this
answer
helpful?
Yes
No
Wednesday, July 11th, 2007 AT 7:17 PM
Tiny
LEB
  • MEMBER
Actually, as I think about it more, the over heating can be caused by the lack of the balancer. The balancer is ribbed, to match the belt. Without it, the belt can slip. If the belt slips, the water pump will not work properly, thereby reducing the flow of water.

This would explain the over heating in traffic. When you are driving at higher speed, there's enought water flow and air to keep the engine cool.

If I remember correctly the balancer is inexpensive - $20 or something, and is easy to mount.

Again, I would focus on the balancer.
Was this
answer
helpful?
Yes
No
Thursday, July 12th, 2007 AT 10:01 AM
Tiny
JIMKAWA2001
  • MEMBER
The belt does not squeal like it is slipping. I used a small enough belt and tightened it until the squealing stopped. Could it still be slipping?
Was this
answer
helpful?
Yes
No
Thursday, July 12th, 2007 AT 3:26 PM
Tiny
LEB
  • MEMBER
I'm not sure if it would necessarily make a noise or not.

Is there a problem putting the balancer back on? All you have to do is take the belt off, bolt on the new one (three bolts IIRC) and put the belt back on.

Then test it.
Was this
answer
helpful?
Yes
No
Thursday, July 12th, 2007 AT 4:41 PM

Please login or register to post a reply.

Recommended Guides