95 Geo Prizm vibrations inside car and timing belt

[hancockr]

1995 Geo Prizm Lsi 1.8l Auto approx 138,000 miles

2nd post on this car…I have been driving it for a few weeks now (was fiancée’s car and we got her something newer). It sat in my garage since last November and I finally decided that since it wants to keep running (a little rusty and one door crushed) and gets way better MPGs than my pickup, it would be a good to keep it going.

Slowly working through a list of problems/annoyances and these are next:

There is a terrible vibration between 25 mph and 40 mph (no tach, not sure of the rpm) which rattles or sets buzzing any item in the glove box or door pockets and threatens to shake loose every fastener inside the car. It is also not very nice on the ears at some speeds (deep rumble or roar, not sure what to call it). The exhaust is solid and not leaking anywhere. Muffler is good. In fact, outside the car you would not think there was a problem. Since I also get a slight jump and a squeak when I drop it in reverse, I am tempted to think motor mounts are shot. Is this about the “right” age/miles when they tend to go bad? Also this car has spent its entire life in Michigan, so there is the salt and rust thing going on…

Second thing is the timing belt. As far as I can tell it has never been replaced. I am sure it is only a matter of time before it removes itself if I don’t get to it first. Just wondering what other’s experiences have been with this engine and if I should be replacing the water pump (and/or other parts?) at the same time.

Any suggestions on where to buy parts which are reliable but not terribly expensive?

Thanks for the help

Randy

[bigd480]

Yes I had motor mounts replaced around then but they probably needed it sooner. See if the vibration is stronger on the passenger side - that top mount fails often.

[Bitter]

pass side and trans mount fail and cause vibrations front mount should also be replaced, rear mount might be bad but is a pain to replace. also check wheel balance.

[hancockr]

Thanks for the suggestions. I will probably just do the motor/trans mounts at the same time I do the timing belt. It is not the wheel balance since the vibration also exists at idle when the car is not moving. Kind of reminds me of my old Mercury Lynx diesel. At idle that thing had a pretty strong vibration.

Again, though, any place anyone can suggest to buy good parts?

Thanks