Classic "shuddering" bonneville problem
 

Hey guys,

My bonny and i have been through a lot, but for the past year or so it has done the classic 'shuddering under load'. I dreaded the large cost of a rebuild on the transmission, (thus the putting it off) but i finally scrapped together the cash around christmas and took it to my transmission guy. He said that there was no way it was a transmission problem and i was more likely to find something write with the front end (alignment, tire balancing, from axels etc). This came as quite a relief to me. I took it to my local bell tire and had them do the high speed balancing, and they also noticed that my two front rims were bent and my right front axel was 'recommended' to be replaced.

I want some expert opinions here

Symptoms:

Car has a gentle vibration all the time (i assume thats the wheels), but every once in a while (i'll say once every two weeks) i'll get in the car, start it and the SES light will come on. The SES light will stay on and the car will vibrate so horribly its difficult to drive. Usually once i turn off the car and let it sit (through school or work) it is fine when i come back to it (it just has the normal gentle vibration).

I know the canned solutions "regular maintenence... spark plugs wires... fuel filter... etc" i've done all that. I'm preparing to hunt down replacement rims as well as get the axel done, but if thats not whats causing my major problem than thats not what i want to do first.


Thanks for your help

Need to find out the code resulting from the SES light. Have a mechanic or someone with a scan tool get it for you.

We can't know exactly what's wrong until you pull the codes, but I'll put in a piece of something that happened to me that seems to be similar to what you're experiencing.

The gentle vibration happened to be a pair of bad rims on mine as well, and replacing those with identical rims I found from a junkyard made the car run as smooth as butter. This vibration would only occur in a certain speed range, so it was the most likely symptom.

A month after purchasing my car, I also experienced a horrible shudder associated with the SES light, which felt like a cylinder was missing. I took it to three different shops, each one with a different opinion (but never estimating anything less than $1300 in repairs). So one day, I decide to disconnect and reseat all the electrical connections under the hood. Low and behold, the ones that finally corrected the situation were the connectors for the fuel injectors. I'm guessing that one or more cylinders wasn't getting fuel at all, causing the miss, and the horrendous shudder. This also seems to corroborate with the fact that the shops pulled a code for a problem with the ignition system. Problem hasn't returned since (and I saved $1300!).

So just in case, I would pull all of the connectors under the hood, give them a shot of contact cleaner (maybe light sanding with fine sandpaper if they're really corroded or oxidized) and reseat them firmly. See if that helps the situation. Good luck!

Thanks,
I will clean all my contacts. Does anyone know where i can 'borrow' a scantool (like autozone or murrays) that will work on my 94. i'm in the detroit area if anyone knows any specific stores.

Autozone may retrieve the code for a nominal fee. Otherwise they may have some Actron scanners on the shelf. Make sure it's OBD-1 compliant and has a 16-pin harness. CP-9110 + CP-9111 + CP-9115 will work.

the autozones around here will do a 'check engine light' analysis but they say they only do 96 and above.. i assume that means ODB2. Heres my problem. My bonny is a 94 but i think it has the odb1 computer with an odb2 connector. Can someone verify what the different connectors look loke for me?

You're correct about the connector. Autozone got my codes before, and I've got a 92.

You have a 16-pin connector, similar to the connectors on 96 and up with OBD-II.

But you have an OBD-1 computer. Doesn't Autozone have OBD-1 capability?

i'm gonna give it a shot this weekend... i'll post my results