Vibration with acceleration
 

Hi everyone,

I have a '98 4runner automatic SR5 3.4L, 202,000 miles, which has run beautifully until today. While accelerating from a turn this morning a terrible screeching sound started, pretty sure from the engine bay though not certain, and would persist every time I reached 2,000 RPMs. Below 2,000 RPMs or in neutral and there was no sound, when coasting there was no sound. I parked the car and left it for a few hours. Later when I got in and started driving the screeching sound had disappeared, but the car was now vibrating (starting right when I put it in drive) and as I accelerated it continued getting worse. Pulled over, put the car in reverse and there was vibration. Neutral and there was no vibration. Drive, vibration. Sounds like driving on a rumble strip on the side of the highway and the car visibly shakes. While I was driving, the engine light momentarily flashed on, but quickly turned off.

I know there's been a lot of posts about a failed u-joint, which may be the problem, but I wanted to get someone's opinion on this specific problem. I thought it was a belt issue, but I had the timing belt replaced and front/rear differential service at 187,000 miles so I'm thinking it may be something else, however nobody else has described a problem that starts with screeching and turns into shaking. I just got back from jacking up the rear, where I tried rotating the rear tires back and forth to see if I could identify the source, and there is a slight knocking coming from somewhere around the u-joints and rear differential... so all signs are pointing towards a failing u-joint

BUT what explains the screeching and engine light?? Any ideas??

If you didn't say you'd had the timing belt done already, I'd say timing belt.

Sounds like a cracked flex plate.

Maybe 2 unrelated issues. Maybe not. What is the check engine code? Might still be stored in the computer even the light turned off