'86 Buick hard idle fix (took awhile)
Steve M.
07-08-2004, 11:25 AM
Although I never posted a question here (maybe I should have) I'd like to share this. Other websites had creditable suggestions, just not the right one. (Timing, timing belt, EGR valve, tranny, etc, etc.) Turned out to be “the last place one might look”. Hope this may help someone in the future.
Our Buick is a 2.5l 4cylinder we bought in Florida with 22k original miles on it. The problem started last year, somewhere around 55k miles: A very hard/rough idle when the car was stopped at a red light. It was so terrible, the car would idle down to the point the steering wheel vibrated and the battery light went on. After looking into all suggestions here’s what I found to be culprit:
The rubber bushings on the engine torque strut were so worn that the engine began to vibrate on the metal portion of the strut. I suspect alignment may have been an issue as well since there were several inches of front-to-back play. In park with the hood up (engine not running) you could rock the car forward and backwards and see the engine move to the point where it was scary. One Buick dealer said, “That’s normal.” Ya, right. LOL
Facing the front of the car – hood open – the engine torque strut is in front, left of center, mounted between the engine and the frame cross member at the radiator. It resembles a dumb bell, made of cast aluminum with rubber bushings at each end. It was a $10.00 part and took 10 minutes to replace.
When anyone asks me how in the world I figured this one out, I simply respond with, “Must have had some help from above”. Quite honestly I should have suspected something when the car idled just fine in reverse (engine torque different), and it ran fine on the road. Glad I didn't run to the shop to have everything "fixed"!)
Steve
Our Buick is a 2.5l 4cylinder we bought in Florida with 22k original miles on it. The problem started last year, somewhere around 55k miles: A very hard/rough idle when the car was stopped at a red light. It was so terrible, the car would idle down to the point the steering wheel vibrated and the battery light went on. After looking into all suggestions here’s what I found to be culprit:
The rubber bushings on the engine torque strut were so worn that the engine began to vibrate on the metal portion of the strut. I suspect alignment may have been an issue as well since there were several inches of front-to-back play. In park with the hood up (engine not running) you could rock the car forward and backwards and see the engine move to the point where it was scary. One Buick dealer said, “That’s normal.” Ya, right. LOL
Facing the front of the car – hood open – the engine torque strut is in front, left of center, mounted between the engine and the frame cross member at the radiator. It resembles a dumb bell, made of cast aluminum with rubber bushings at each end. It was a $10.00 part and took 10 minutes to replace.
When anyone asks me how in the world I figured this one out, I simply respond with, “Must have had some help from above”. Quite honestly I should have suspected something when the car idled just fine in reverse (engine torque different), and it ran fine on the road. Glad I didn't run to the shop to have everything "fixed"!)
Steve
occupant
07-22-2004, 07:24 PM
That "dogbone" is a common problem on all A and X body GM products. It's a cheap part. They make a polyurethane bone for it, costs more like $30, but lasts way longer. It's surprising what all problems can happen just from a loose motor mount like that!
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