: 94 Eldo motor shaking



10Miler
11-09-10, 12:00 PM
Trying to figure out why the motor on a 94 Eldorado is shaking. It happens at idle, and while driving as well. This car is not mine, but belongs to my grandmother. I am going to sell it for her, but I would prefer to have it running well before I list it. I don't want to purchase a bunch of parts but if there are some fairly simple fixes I can try I would like to do it. Thanks!

Ranger
11-09-10, 05:03 PM
Not enough info. Got any DTC's? Is it missing? Are the motor mounts leaking?

miwise
11-10-10, 06:50 AM
Hmmm. Could be a lot of things. I'd start with a compression test to ensure compression is even across all cylinders

miwise
11-10-10, 06:56 AM
Check coils to ensure u have spark. Pull codes to ensure oxygen sensors functioning correctly next. Etc. Mine has a shake too but because it was overheated. I bought my engine from a salvage yard. (my second engine. The first self destructed bc the lower end was rebuilt. I hear the lower girdles do the same thing the heads do). Anyways. Just check one thing at a time. Inspect wires and plugs. U will find culprit

10Miler
11-10-10, 02:44 PM
I guess I didn't have automatic email notification setup, so I just saw these responses. I just picked up the car. It doesn't shake at highway speeds, only at lower rpms or idle. That leads me to believe that it is the EGR valve.

Also it has other issues too, like a sort of rattle or bumping sounds from the front passenger side tire/suspension area. Maybe a bad bushing or something? I might have to pull the tire off and have a look.

My relatives think that this car will sell for > 3k, but unless these issues are fixed I don't see it going for more than 2k.

It was just in the shop for $1100 worth of work, and I am suprised that the mechanic or shop manager didn't mention these very obvious issues.

10Miler
11-11-10, 01:40 PM
This morning I pulled the EGR valve and the plunger on the bottom would not move. So I sprayed it with carb cleaner to loosen it up and now it runs much better! Then I jacked the front passenger side of the car up to start looking at the suspension/steering components, and noticed that that the spring/strut assembly was loose. The top strut mount nut looks loose. What size nut is that? Also, is there supposed to be a washer or bushing under the nut? Looks like a LOT of play for the strut rod to move around in the strut mount area.

Thanks for all your help!

Ranger
11-11-10, 09:34 PM
You need to do a little more than just spray the EGR valve to get it clean. When I did the one on my wife's '96 Bonneville this summer I had to clean, spray and pick the pintle valve and the inside with a dental pic for a good 30 minutes to get all the carbon out so it would move without sticking. You may have to go back in before too long.

10Miler
11-12-10, 08:07 AM
You need to do a little more than just spray the EGR valve to get it clean. When I did the one on my wife's '96 Bonneville this summer I had to clean, spray and pick the pintle valve and the inside with a dental pic for a good 30 minutes to get all the carbon out so it would move without sticking. You may have to go back in before too long.

Yeah, I see that now! The valve seemed to move freely, but the car motor is still a little rough from idle to about 1800 rpms. Still it's better than it was before.

And about the strut issue, I went to the auto parts store and they let me use a 24MM socket to try to tighten the nut, and it just turned and turned. So apparently someone has been into that strut mount and didn't reassemble properly. There is a clip that needs to be installed on the underside so that the nut will tighten.