i got a 89 3.8 from a friend and swapped it into an 88 cougar Lx,the 89 had the harmonic balancer missing so i put the balancer from the 88 on it and upon acceleration it shimmies/vibrates.when i put it in park and hold it at a steady rpm it has a vibration. is there a difference between the 88 and 89 balancers/is the 89 3.8s internaly balanced?has new plugs,cap,rotor and wires.any suggestions would be appreciated. Mike:cougarsmily: :cougarsmily:
I don't know if there's a difference.Are the motor mounts in good shape.I had a shimmy problem with my old (long gone) 3.8,and the rubber insulator on the driver side motor mount was vapor.The mount fixed my problem.
motor mounts are new,replaced with engine.both mounts on the old engine were trashed,i have a 5.0 from a markII but decided to keep it for a future project.
The 1989 3.8 did not have a balance shaft...only the 1988 did, under EEC-IV. If you're installing a 1989 motor you should not have to install the balance shaft. There may be other issues (dampener, flexplate, converter, driveshaft) that are being affected by it being in there. I would suggest removing the balance shaft and seeing if the vibration goes away. That's about the only thing you can do at this point.
just got home from work,thanks for the replies.i took the engine out of an 89 so i assumed it was an 89 engine,before i installed it i put new gaskets on and it had the balance shaft already in it,may be ill just sell it and start saving for the next project.thanks