[alilredjeep]

My Jeep ran hot while on my way to work this moring. I assumed it was just a stuck thermostat but this afternoon when I got a chance to check it out, I could hear a rattle at the front of the engine.
Before I start throwing money at it I just wanted to ask if anyone has ever had a water pump to cause their Jeep to run hot, yet not leak any water.
My first suspicions was a stuck closed thermostat because when I turned on the heater I noticed there was no heat at all coming from it.
Maybe its the waterpump and the thermostat.
Anyway, I'm just curious, I've never had any engine to overheat due to a faulty waterpump unless it was leaking at the waterpump seal/bearing.
Also about what does a rebuilt waterpump cost for a 92 YJ with a 2.5 engine cost?

Thanx in advance,
Eddie
A.K.A alilredjeep

[CanukYJ]

As for the rattling make sure all the belts and pulleys are nice and tight, could just be a belt slipping a bit causing a decceleration of the pump resulting in less coolant flowing. Its a long shot cause belts normally squeel but you never know. As for no heat from the heater while the engine running hot, that is almost surely a stuck thermostat, only a 5$ part and a 1$ gasket might as well do that and see what happens.

[LoOpY]

if the thermostat were stuck closed (as it would need to be to cause overheating) you would have AWESOME heat.

it is within the realm of possibility that an impeller could be damaged without the bearings or seal going out... however unlikely.

it bothers me however that you say you were overheating, but your heat didnt work. Makes me wonder if you have a blockage somewhere, restricting coolant flow

[alilredjeep]

Originally Posted by LoOpY

if the thermostat were stuck closed (as it would need to be to cause overheating) you would have AWESOME heat.

it is within the realm of possibility that an impeller could be damaged without the bearings or seal going out... however unlikely.

it bothers me however that you say you were overheating, but your heat didnt work. Makes me wonder if you have a blockage somewhere, restricting coolant flow

Loopy,

I was about 7 or 8 miles from home when I switched on the heater and got cool air out of the heater ducts, thats when I noticed that my temp guage was pegged out at 260.
If I hadn't decided to turn my heater on, I would have surely fried the engine before I noticed anything was wrong.
There was no check engine lights on, steam or water loss or anything that would have let me know something wasn't right.
Maybe it is just a stuck thermostat and a water pump that is on its way out.

alilredjeep

[Mels95YJ]

Just a thought, but have ya checked your antifreeze level? After I changed my thermostat, I didn't fill it up all the way, and my temp pegged out. After filling the radiator up fully, it ran normal. Just a thought.

Mel

[BamaJeeper]

You may have a clogged radiator. Open the cap and if there is alot of corrosion then it's probbly clogged.

[alilredjeep]

Just a note to let ya'll know what I found out and ask a question about it too.
I have removed the thermostat and tested it in a pot of boiling water. It opened up all the way from what I saw so I assume that it is in working order.
Next, I removed the water pump. and saw what I beleive is an obvious failure on its behalf.
As I bumped the pump to unseat it from the block, the impeller fell out of it and landed on the ground.
I cant see anyway as to how the impeller was ever attached to the pump shaft.
Was it supposed to be a press fit, tack welded or what? The pump looks to be fairly new but I'm not sure because I've only owned this Jeep since the first of March, 03.
Has anyone else seen this happen before? Is it common?

TIA,
alilredjeep / Eddie

[LoOpY]

very uncommon from what i understand, as i said earlier. according to my instructor last year (hes been in the feild a good 50 years) hes only seen one failed impeller where the weep hole was not leaking.

glad to hear you got the problem isolated. congrats