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Grand AM water pump, Help!

I have a 94 Grand Am with the 2.3 liter engine Single Overhead CAM (vin 3, I think). I have just got over 200k miles. I think the car sensed I was starting to lock at newer cars. Well the water pump just went out.

I am in the process of replacing the pump. I have everthing off. The exhaust manifold, pump housing and pump. Now the problem. I go to mount the new pump to the timing chain housing and it won't go. It mates up with the splines ( I had to rotate it slightly) and then it bottums out. It needs to go in about 1/8inch farther. I have measured the pump for the distance from the pump housing mounting flang to the end of the splined shaft. It is about 0.925 inches. I did a depth measurement on the female end if the idler. It is about 0.817 inches deep. The difference is about an eight of an inch. I have got another pump from NAPA this time, thinking it is the wrong pump. The pump depth dimension is pretty close to the first pump.

I have looked inside the housing at the idler. I don't see anything damaged or out of place. The snap rign is still in place. and the idler bearing looks ok.

Important note: I checked the old pump and found that the distance from the shaft end to the mountin face is about 1/8 shorter than the new pump. However I can push up on the pump impellers and make up for this difference (about 1/8"). The pump tends to spring back. Push up

1/8".

I can only think of two things that may be the cause.

  1. The pump is still not the right one for the car. The pump may be different for this particular VIN. In which case I may have to go to the dealer and check out a pump from them.

  1. The idler and bearing have moved out of the housing seat by 1/8 of an inch. If this is the case how will I reseat the bearing. The book says I have to take the housing off and take it to get the bearing pressed in to replace it. I hope i don't have to take the timing chain housing off. If this is the problem then this may have been or contributed to the demise of the pump.

Experience... Comments...ideas, please. The help is appreciated.

Thanks Kevin

Reply to
Kevin
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"Kevin" wrote

If you are fooling around with aftermarket pumps...I'd suggest that you stop right now and go get a GM pump. Perhaps the aftermarket ones weren't assembled right. Just bite the bullet and get a new pump from GM and then you shouldn't have to worry about stuff like this.

Note: make sure that you draw the water pump housing up to the block and water pump in small increments. You want to make sure that you do not warp the housing or put undue stress on it or the water pump. Do you understand what I'm saying here....because you have two bolts going into the block and 5 bolts going into the water pump itself and there is a 90 degree difference between the two sets of bolts...you can't just tighten one set up first without making sure the other set of bolts are very close to being tight themselves.

Ian

Reply to
shiden_Kai

I stoped by a dealer and looked at there pump and it looks like it has the same dimension as the two after market ones I have. I don't think it is the pump at this point.

I think I see what is going on. The idler shaft has a spring loaded end on the base of the female end (with the splines that mate to the pump). I took a screw driver and was able to push on inside of the idler to feel the spring. It seems to be a pretty stiff spring. I will have to put the pump in place as before and then push the pump on to get the nuts started. This was supprising since my haynes manual does not mention this.

I stoped by a dealer and looked at there pump and it looks like it has the same dimension as the two after market ones I have. I don't think it is the pump at this point.

Yes I understand your comment about the two mating surfaces. I will leave the bolts somewhat loose/snug until I can thighten all about the same time.

comments?

Kevin

Reply to
Kevin

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