Pontiac: 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.

2. 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

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 have looked at three pumps now and
they all look the same the shaft sticks out above the pump body by the
same dimension.

Looking at the old pump, I can push in on the impellers about 1/8" and
watch the splined shaft go up about an 1/8", to where it would match
the new pumps. The water pump shaft also seems to be spring loaded as
I can push on it and it spring back. Also the bearing in the old pump
has the seal pulled out of the inner race. If the pump bearing wore
out and the idler spring pushed on the shaft, the inner race seal
would pull out of the inner race. I may try to take the old pump apart
to look at the bearing.

It seems that as the pump was failing, the spring in the idler pushed
the pump shaft out. The pump impeller started to scrap the water pump
housing (the housing that bolts to the water pump the outlet pipe and
the block). The scrap marks are obvious.

When I put the pump on previously, I rotated the pump shaft to align
the splines. The pump would go on farther, but it would button out
about 1/8" away from bolting cleanly to the timing chain cover. The
mating end of the splined pump shaft looks exactly like the photo in
my haynes manual. In the female splined end in the idler appears to be
disc with a hole in it. I can push on it with a screw driver and feel
a spring in it.

I think I just have to put the pump back on and push the pump on to
compress the spring to get the nuts started on the studs. My concern
is that the haynes manual does not mention this.

Whe you replaced these pump have you had to compress the spring to
mount the pump? BTW I have a vin number 3 grand am SOHC 2.3l


Thanks
Kevin

net (GREASY DICK) wrote in message news:<bay.webtv.net>...