Re: Please, is this leak the water pump?

Why would you think it is a cracked block?

This could also be a head gasket problem.

Indeed, what type and size of engine do you have?

If you have the 2.8 or 3.1 V6, then the water pump is likely built into the block and located at the front of the engine - so this would elminate it as a source of trouble. Too bad, because those integrated water pumps are cheap and easy to replace (if the engine style is the same as my corsica).

Please give us more details.

"Mike" wrote

From your description, I'd say that the water pump is leaking. It's very difficult to see the water pump vent hole on these engines, but if you have coolant running down the oil filter area, that's exactly where it would leak if the water pump was leaking. Note: there is also a bypass hose that runs very close to the top/back of the water pump that can leak. But it usually will flow coolant behind the water pump/oil filter area.

I doubt you have a crack in the block. If you have the timing belt off, you are halfway there. Remove the tin backing plate that goes over the water pump and check the water pump. At that point it's 3 bolts and water pump will be in your hands. You should be able to see coolant tracking right out of the vent hole.

Ian

Thanks for the help, guys,

The engine is a 2.0 4-cylinder, automatic, with 109k miles on it (one-owner, me, and I've tried to take good care of it). The water pump is on the passenger side of the engine, and once I removed the wheel well I can reach the water pump pretty easily. The main belt is one big belt with a tensioner pulley that I can move by hand to take the belt off, and the timing belt cover goes behind the water pump pulley. When facing the engine from the passenger's side of the car, the leak looks like it's coming from about 4 inches closer to the firewall than the water pump, but I can't see the top of the water pump at all to see if it extends over that far.

When I'm laying underneath the car, touching the oil filter, I can reach my hand up to go over the frame, and hold onto the passenger-side rear motor mount. With a flashlight in my hand, and craning my neck just right, I can see water coming from behind the motor mount, maybe 2-3 inches above the oil filter. I can sort-of see the top of the motor mount, and it looks dry there.

The head gasket is easy to reach from the top of the engine, and it LOOKS like the leak is coming from a lot lower than that; maybe 8-10 inches lower? I can't see any signs of rust or water around the head gasket, but from underneath it looks like the leak has been going on for awhile and it has a lot of rusty build-up. Based on this, I think I can rule out the head gasket.

Early last year, a mechanic replaced the timing belt, and at the same time flushed the radiator. He filled it back up with plain water without my knowing it, so over the winter it totally froze up. I let it dry naturally, but when I started noticing the leak I went to a different mechanic who "glanced" at it and said that it was either the head gasket or a crack in the block (I sure didn't trust the guy when he quoted me a price to fix it of $400, and hadn't even looked to see exactly what the problem was). I can't see anything else in the vicinity of the leak other than the water pump; no hoses or anything. This is why I'm worried about a crack in the block; if it's not the water pump, I don't see anything else that's coolant-related near here, and there might be a crack behind the engine mount that I'm not seeing.

The Haynes manual mentioned a freeze plug, too, Larry, but I couldn't find it on the engine. Underneath is pretty grimey from an oil-pan leak that I fixed myself, so it could be hidden beneath a lot of grime. Assuming it would be on the bottom of the engine, though (meaning it would be easy to reach from underneath), then the leak is definitely too high up. The leak isn't really fast enough to think that a plug could be completely gone, but it's possibly a cracked or shifted plug. I wouldn't think that a plug would be this high in the engine, though, would it?

Thanks again, guys, I really appreciate your help,

Mike

PS, I tried to use some liquid block sealer (K&W), but that had no affect at all. Although I know that would have been a temporary fix, I'm HOPING that the fact that it didn't do anything implies that it's not a cracked block. Mainly wishful thinking, though.

It froze during the winter with plain water in it? Did you check the freeze plugs ?