I did an engine swap from a 2.8 to a 3.1. The 2.8 I had in the car had an 5spd. The 3.1 was auto. So I basically took the manual parts and slapped them on the 3.1. Here's my problem. At idle I get some vibration. It shakes the whole interior pretty much. My friends dad said that it was possible that the 3.1 takes a different flywheel? Somethings not balanced right it seems. What did I do wrong?

 

def sounds like a imbalance problem well let me ask u this did everything bolt up ok

 

The 3.1 uses the same flywheel as the 86-89 2.8. Your 2.8 was in that year range wasn't it.

 

Yes everything bolted up fine. I figured the 3.1 did since I heard it's pretty much just a bored and stroked 2.8 Or something along those lines. Although I did not have a torque wrench at any time during the install. For instance when I installed the flywheel and the engine to bell housing bolts. Should I drop the tranny and take the flywheel off and torque it down this time? Is there a bolt pattern?
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Yes. I have a 87.

 

The flywheel should be good then. You can torque the bolts just zig zag across each other when tighting.

 

IT happened to another member as well. He had an earlier block in his '87, and the pre-85 blocks had an external balanced crank. You may have this same situation.

If you have a miss-match on the flywheel and crank, this will happen, and could be the result from a few things...

1. Engine you installed is actually an early 2.8 and needs the balancer on the flywheel.

2. Your original engine was actually an early crank and you put the balanced flywheel on an internally balanced engine.

Did you notice a counter weight on the flywheel when you had it apart?

Otherwise it could be that it's not bolted properly, but it only goes on one way on the crank without a lot of force.

 

could be flywheel vibration... though you should've just kept whatever was on the engine (flywheel, balancer, crank) on it when you swapped it...

another thing to consider would be a damaged or improperly installed flywheel... I had a 5spd missing a few teeth vibrate on a 2.8L... also have torqued the flywheel bolts in the wrong order and had flywheel vibration...

don't be cheap, go to a local auto parts store and buy a torque wrench for some $40... any job bigger than an oil change should involve a torque wrench... I learned that a LONG time ago

you didn't actually pull the tranny right? a failing u-joint can cause a pretty wicked vibration too...

 

Well being that the engine had an auto tranny hooked up to it, I had to take off the flexplate, torque converter and such. I hooked up the flywheel straight to it and then the clutch then the pressure plate. Then my T-5. So pretty much my best bet would be to just pull the trans out and see what's up?

 

when you took off the flexplate you put the 2.8L flywheel on? that could be your problem right there like firstfirebird said...

I'd expect you need the non balanced flywheel, but without knowing the year of the 2.8L... it's hard to say for sure..

chances are you probably will have to take the tranny back out

 

You need the flywheel for the 3.1, not the 2.8. I had to swap the flexplate out in my Camaro twice because I didn't know that my motor was pre 86 when my car was an 89.

 

Yea you can't go on year of the car 100% but if you have the old flex plate still, it will tell ya. It will have weights on it or not. It will be netural balanced or not.

and yes you should have a 3.1 flywheel if you got a 3.1`