Do I really need a water pump?

I know I NEED one. But here's the deal. I was driving my Jeep to work one day and when I got out, there was coolant pouring out of the engine. It wasn't the radiator, and the lower hose looks okay. For the amount of water that was pouring out I would think the hose would have to break in half. I pulled the water pump off and it looks okay, but I don't really know what to look for. While everything was still together I tried looking for the weep hole, but couldn't see it, and the water just seemed to be dripping down the oil pan. Should I get another pump? I don't want to shell out $40 for a new pump when its not the problem. Is there anything else that could have gone bad?

If the water pump has more than 100k miles on it, and you already have it out, I just replace it with a good quality replacement. I don't know if that the problem, but at least you eliminated the water pump and replaced something that will wear out eventually anyway.

If your determined to fix it as cheap as possible, then you have to inspect everything else and try to find the leak. Can't find it, and your not willing to replace or can't afford to replace the water pump, just on a hunch, then you'll have to put all back together and run the car and try to find where its leaking.

Clean the motor thoroughly, so you can spot the source of the leak. You looked to make sure the headgasket wasn't leaking? OR the head wasn't cracked, RIGHT? A cracked hose/head/block or bad freeze plug may leak as bad as you described, a bad headgasket is not likely to leak that much, you'd have a lot of other problems and/or symptoms if the headgasket was that bad.

When my water pump went it squeeled like a pig. Didn't leak though...

I just went through this last week, water was leaking down my lower radiator hose so I though my clamp on the lower hose at the water pump crapped out for some reason. Checked it and it was tight. Looked a little further and it was coming from the water pump. From what I have read, these start to leak a little to let you know that they are about to take a SH!*. Put in a new pump, no problems now

Even one I talk to says they usually hear bad noises from the pump and small leaks. That's what makes me think it's not the pump, since I never heard anything. And I don't think it's the head gasket. Aside form the Jeep running pretty well, the coolant was leaking at the bottom end, not top. I never thought about a freeze plug though. Are there any located around the water pump?

The Water Pump has bearings and seals. If the seals goes bad, but the bearing is still good, the water pump will just leak, until the coolant washes away the bearing grease and then the bearing will go as well.

When the bearing goes, you'll get the noise.

If the bearing goes first, you'll get the noise, the seal may stand up for a while and thus just noise, no leak. Eventually, the bad bearings will cause enough heat to ruin the seal or the bearings will grind up and the shaft will wobble and tear up or tear out the seal completely. If the seal tears out completely, then the entire coolant system will dump in a matter of seconds and leave you stranded. (The seal tearing out from totally shot bearings happened to me, in a another vehicle).

To sum up; there are several ways a Water Pump can fail, they all will eventually cause the pump to leak, they might not always make noise.

They dont always make a noise. Some start a little leak in the morning and are running water in the afternoon...If it is leaking at the front down to the oilpan, the head isn't visibly leaking, the hoses aren't visibly leaking, the thermostat hoses and gasket aren't leaking, the radiator isn't leaking...there is only one other option...The Water Pump!

Replace it since you already have it out, if the leak is fixed, you are done. If you put the old one back on for further troubleshooting and the leak is still there, what would that accomplish? More work.

The water pump is a good investment right now with the summer months of heat fast approaching. I would replace the thermostat too since you have the system cracked open now. What year is the Jeep, open or closed cooling system?

Cory

csr_011 said:

They dont always make a noise. Some start a little leak in the morning and are running water in the afternoon...If it is leaking at the front down to the oilpan, the head isn't visibly leaking, the hoses aren't visibly leaking, the thermostat hoses and gasket aren't leaking, the radiator isn't leaking...there is only one other option...The Water Pump!

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Actually there are two other options. The second is a crack in the front of the block where the water pump meets it. I've seen two 4.0 blocks that each had a 1/4" crack at 90* to the rim of the front opening to the water jacket.

Dr. Dyno said:

Actually there are two other options. The second is a crack in the front of the block where the water pump meets it. I've seen two 4.0 blocks that each had a 1/4" crack at 90* to the rim of the front opening to the water jacket.

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I'm not sure where this is. I'm not exactly looking at the front of the engine either. What's the water jacket? This would be noticible right? I'd see a big line on the front of the block? And how would this effect oil pressure? I drove the Jeep around a few times after filling the system back up with water, no problems. Just a lot of green water on the ground.

alpinetiburon04 said:

I'm not sure where this is. I'm not exactly looking at the front of the engine either. What's the water jacket? This would be noticible right? I'd see a big line on the front of the block? And how would this effect oil pressure? I drove the Jeep around a few times after filling the system back up with water, no problems. Just a lot of green water on the ground.

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Take a look at the photo below.



You can see the opening to the water jacket in front of the no.1 cylinder sleeve where the water pump mounts up. The metal around the edge of the opening is quite thin and I've see two blocks in a Jeep workshop that each had one tiny crack perpendicular to the edge and leading to it. If the water pump was bolted on, you wouldn't have been able to see the cracks.

Dr. Dyno said:

The metal around the edge of the opening is quite thin and I've see two blocks in a Jeep workshop that each had one tiny crack perpendicular to the edge and leading to it. If the water pump was bolted on, you wouldn't have been able to see the cracks.

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I'm still betting on the water pump tho. Cracked block would be pretty rare, although something to check out when you remove the water pump.

Related info to a bad water pump: when the pump went bad on my MJ, it never leaked or made noise. The temp. gauge climbed up to "too damn hot" and stayed there. I pulled over, shut down the motor and waited about a 1/2 hr., then checked everything. Everything looked ok, except for being low on coolant, so I fired up and drove towards home. Had to stop two more times in less than 5 miles. The problem ended up being the impeller on the back side of the pump had been spinning on the shaft, but not fast enough to move the coolant. The impeller is NOT supposed to move if the shaft is held in place. That was my trouble, so if you have similar problems, and everything looks good, check the impeller for seperate movement on the shaft. By the way, I threw a SMALL bead of weld on the new impeller, just as a safety.

just about every water pump has a small weep hole designed to leak when the pump seals start to go bad.