Sudden Overheating

I have a 1990 Jeep Cherokee Laredo.



Recently, I changed the belt in my car. It was working fine for a few days after, but I was out of town for a few days and I didn’t drive my car. When I got back it started squeaking!



Its almost constant, and it is really bad when it starts and when its stopped at a light.



Now, to the topic at hand.



I was driving home tonight and about half way home, I saw that the engine was overheating - badly.



I managed to get home but when I stopped the car you could hear boiling sounds from the engine and there was steam.



Hopefully, its just that I need to check the radiator fluid, and top it off, but I was wondering if it was something else.



Any advise?

If your Jeep has a serpentine belt-driven water pump, you might want to have that checked or replaced. If the pump seized or isn’t working right, it could cause the belt to start squealing, as well as not properly pumping the coolant, which would cause overheating.

Also, maybe just check or replace your drive belt(s). A loose drive belt could cause the water pump to not work properly, again leading to overheating.

Another possibility I can see would be if another belt-driven accessory (alternator, A/C, power steering, etc.) failed, it could damage the belt and cause the water pump to not work properly, causing overheating.

If your water pump is a timing belt driven one, again, maybe it’s not working properly. If this is the case, it might not be a bad idea to get the timing belt changed. Of course, if your Jeep doesn’t have a timing belt, ignore the above advice (not sure if Jeeps use timing belts or chains.)

Lastly, it could be two completely different, but coincidental things. Maybe your belt had some water on it, which has been known to cause some squealing, and your radiator is plugged. Or something else entirely.

Have a look at the radiator too. It may be corroded enough to change. The outside of the core could be green, white or both. Some of the fins between the tubes may be missing. Try to see it from the rear. If it looks OK, pull the shroud back and look again. Ten percent of the fins gone is a guarantee that a new radiator is needed. Anything near five percent could still be bad.

Either your water pump is going bad causing the belt to slip, or the water pump is dripping anti-freeze on the belt causing it to slip. Either way you need to replace that water pump ASAP!
~Michael (Dartman69 can’t log in)

Autozone has an on-line repair guide for 84 to 98 Jeep Cherokees. Here is a link to serpentine belt routing for the 84 to 98 Jeep Cherokee. In case your jeep uses a v-belt there is a link on the right side of the page.

http://www.autozone.com/az/cds/en_us/0900823d/80/15/16/b1/0900823d801516b1/repairInfoPages.htm

In the Engine section of the repair guide under waterpumps, the manual mentions that some water pumps are reverse drive and the case is stamped as such.

Ed B.

If your Jeep has a serpentine belt-driven water pump, you might want to have that checked or replaced. If the pump seized or isn’t working right, it could cause the belt to start squealing, as well as not properly pumping the coolant, which would cause overheating.

Also, maybe just check or replace your drive belt(s). A loose drive belt could cause the water pump to not work properly, again leading to overheating.

Another possibility I can see would be if another belt-driven accessory (alternator, A/C, power steering, etc.) failed, it could damage the belt and cause the water pump to not work properly, causing overheating.

If your water pump is a timing belt driven one, again, maybe it’s not working properly. If this is the case, it might not be a bad idea to get the timing belt changed. Of course, if your Jeep doesn’t have a timing belt, ignore the above advice (not sure if Jeeps use timing belts or chains.)

Lastly, it could be two completely different, but coincidental things. Maybe your belt had some water on it, which has been known to cause some squealing, and your radiator is plugged. Or something else entirely.

Thank you so much for replying so quickly! Jeeps have a chain. I just got the serpentine belt replaced. So, I am going back to the shop that “fixed” it. They said that they’d do something about it.

Not really enough information to make a diagnosis… It could be something simple like a sticking thermostat or low on coolant, it could be something a little worse like a slipping belt or failing water pump, or it could be a failing head gasket. You could start by letting it heat up and putting your hand on the radiator hoses–they both should be hot and pressurized. If not, your thermostat may be stuck closed or partially closed. Obviously you don’t want to drive it in this condition or run it very long hot. Good luck.

Okay, here’s an update. It was the Serpentine belt. They replaced it with a faulty one.

The overheating was caused because that belt didn’t have any traction, thus causing the radiator to not work properly. So I lost almost all of my coolant.

However, now they are saying that I have a leaky radiator and that I need to get it replaced! And they are gonna charge me 300-400. Lame. I think I’m getting jipped.

The belt has no direct effect on the radiator. What likely happened was the water pump wasn’t working properly (due to the faulty belt) and wasn’t pumping the coolant as it should. I can’t see how that would cause the radiator to leak.

But you can do a check yourself of your rad. I think someone else told you what to look for already, but I’m not sure, seeing as I can’t see the majority of the discussion, as it’s covered by this blasted reply box. Anyway, take a look at your rad from both the fron and back. Do you notice any vertical streaks of white or green? Are puddles of coolant under the radiator? Are there puddles of coolant on your driveway?

When I checked, I didn’t see any leaks. I’ve never noticed any liquids under my car unless it was raining. I honestly don’t think there’s a leak.

But yea, I get what you’re saying about the belt, though.

It is not uncommon for a new belt to stretch a bit as it is being broken in. I don’t think your Jeep has a spring loaded tensioner on it(correct me if I am wrong here). The tension is set with a manual adjustment. I can only speculate, but I would bet your shop did not tension it enough when they installed it. It streched enough in the first few days allowing it to slip over the water pump pulley and thus you over heated.

It is a lot easier to tell you the belt was faulty versus them admitting fault and causing you this grief. I hope they did not charge you for installing a new belt.

I suppose it is possible, but has anyone here ever seen a new, properly installed serpantine belt fail after a few days, because of a manufacturing defect?

When you added water to the radiator never use tap water. Always use distilled to avoid electrolasys corrosion.

Heh, mechanics are mean! But no, they didn’t charge me. I wouldn’t let them.

And I used distilled water. I knew about the tap water thing being a no-no. I’ve seen what it can do.