low miler

I just sold a '91 GT with 24,000 miles on it to a gentleman in California. He has stated that the car has a shudder between 1500-2500 rpms. I had the motor mounts along with all other aspects of the car checked out prior to the sale. Is there anything other than the motor mounts that would cause a similiar symptom to worn mounts?

ViribusUnits

Worn transmition mount?

low miler

How much is a transmission mount to fix?

mpesik

Hi Mr.lowmiler. Did you not sell your vehicle -as is- ? Did you give this guy some warranty,or do you have a big conscience? Mike.

heinrich

I think this is the kind of approach I would take, and appreciate in others. Not to mention Mpesik, that Low sells 928's as a business, and from what I've seen, he prides himself in the quality of the cars he sells. Just an observation from the sidelines. I've never done any kind of business with Low, but I've seen his posts...
All the best,
Heinrich

low miler

The check was cashed awhile ago, though I feel that the buyer thinks I was possibly trying to hide something, but I wasn't. I noticed a light shudder also, but have experienced a kind of "growl" on some of the other 928's I've sold in the past.

Keep in mind that this is a 24,000 mile car. Now that I think about it, it was worse when it was cold.

My reputation is very important to me and I do have a rather big conscience. I would like to help this guy out if at all possible. Thanks.

ViribusUnits

Well, I couldn't tell you how much it is to repair, as I haven't done it yet. Only thing I know is mine is pretty much shot, just like the engine mounts.

It may not be the transmition mount.

Sorry I can't be of more help.

low miler

Thats okay. Is the tranny mount something that is likely to fail at 25K?

ViribusUnits

IIRC, it's rubber. How about an item thats inclinded to fail after 13 years? Along with most of the rest of the rubber bits and peices?

Weissach

It's the motor mounts. Who ever checked out the car, apparently didn't know what to look for.

John Speake

The problem could be a slight misfire, I had a similar issue when my injectors needed cleaning.

Garth S

Agreed, especially when you mentioned that it was worse when cold.
A picture taked of a straight edge laid lengthwise over the (slightly curved) valve cover to the edge of the cross bar will confirm the degree of collapse.
The mounts in my '88 are fine after they warm up, in <5 min: otherwise, they act as you have described ( new ones are on the bench, waiting for ...).

low miler

That's interesting. I would never have thought that deteriorated motor mounts would ride better after being warmed up. I specifically had my mechanic look at the motor mounts during the inspection because I know they're prone to failure. He said they were in perfect shape.

I would think that if they were even slightly worn he would have mentioned it because it's a nice little chunck of change in labor cost alone to repair. My mechanic, of which for obvious reasons will remain nameless, is considered by those in the 928 community to be one of the best (nationally recognized, magazine covers etc.). If this is the case, I may be looking for another mechanic.

He has replaced many motor mounts in these cars for me over the years, but said these particular ones were fine. I can't help but think it's gotta be something else.

What about this injector thing? Is it possible for a glogged injector to produce similiar syptoms, while cold?

I really do appreciate your responses to this and I have notified the buyer to view this post. He probably is. I would assume that he is eventually going to have the car checked out by a mechanic, but for now maybe just a little peice of mind.

Thank you.

bd0nalds0n

When my engine was first rebuilt, and rebuilt heads were installed, there was some varnish or something on the lifters which caused the engine to run roughly when it was first started.

Based on the advice of the guy who did the work, I used a Swepco additive, and the problem has gone away. From other posts, I glean that just driving these cars after periods of inactivity is enough to take care of the problem. Others have used kerosene as a detergent.

If the car sat for a considerable period, this could be a problem.

nicobel

I'm inclined for the misfire, i had the same problem, because the valve cover seal was worn, and it was letting a little oil into the spark plugs. The result? A bad shuddering ~ 1500-2500 rpm, more often when cold. If it was too cold, it felt pretty bad.

Did you check the seals?, a good thing would be making him check the plugs/cables/distibutors.
A bad motor mount would not create such shudder, because the way the engine works keeps it pretty balanced , it would create a different vibration...IMHO