Jhollin

Hopefully someone can help me. I have a 2002 Grand Cherokee Limited 4.0 V6 79,000 miles. I have had the jeep for about a month and on the way to work last week I noticed the low coolant light come on. When I got to work I noticed the coolant was below the add line. I took it to a shop I was told was good and they ran a pressure check and block test both came back good. They didn't see a leak anywhere but I'm afraid something is leaking somewhere. where would that much coolant go in a month? Any help would be great thanks.

dave1123

Welcome to CF! BTW, that's an I6, not a V6.

The water pump has a weep hole on the bottom of the shaft that has a little chamber under it the holds about a tablespoon of coolant that may seep out of the seal. It's held in the chamber and allowed to evaporate. If the seepage gets too much, it will overflow into the back side of the pulley and get thrown off on startup.

That little bit of coolant loss is nothing to worry about. If it gets to be 2 weeks, then it's worth addressing.

There is one other place it might be leaking. If the cylinder head has been replaced, there's one head bolt that needs sealer on it or it will leak coolant into the #1 exhaust port. You can see deposits on the first exhaust manifold stud nut if that's the case.

Jhollin

Thanks, When I look at that weep hole will I be able to see some sort of bubble? If it where the cylinder head was replaced how would I go about fixing that?

dave1123

In order to actually see that chamber, you have to remove the belt pulley. If it's leaking badly, you can watch underneath the front of the engine on cold startup. I noticed it when we had my WJ up on the lift for some brake work. When a mechanic started it up to bleed the brakes, coolant poured down the front of the engine, then stopped! We looked thru an A/C Delco parts book and they explained that chamber. I had him replace the water pump while it was still in the shop.

If that head bolt IS leaking, you can take it out after draining the coolant, clean it up, and put sealer on the threads. Standing in front of the engine, it's the front, right bolt. It's the only head bolt that's tapped into the water jacket and is only supposed to be torqued to 100 lb/ft. When my mechanic and I replaced the head, neither one of us thought about it, although we didn't read the instructions either! LOL! You should pour some clean water down the hole and let it dry from residual heat before replacing the bolt so the sealer will bond properly.

The way it gets into the exhaust is the coolant wicks up thru the headbolt threads and into the exhaust manifold stud threads, then around the stud nut and evaporates, leaving deposits on the nut. If you don't see those deposits, it's not leaking.

Hunter_

I had the same problem a bout a year and a half ago right before a move.
Had to hop in another car and run to an auto zone about a mile away, and spend a few hours in the garage. wWhen removing the clutch fan be careful that you done band it on the radiator, infact any other part you have to remove to get to the water pump.