Vince A.S

Hey all, i have a 91 xj that runs smooth usualy and nice.. suddenly tonight on the highway heard some noise while pressing on the pedal.. it came almost from the mid section of the vehicle..as am rolling i shift it neutral and pressed the pedal but NO noise..back to D3, pressed the pedal and here comes the noise again as if a piece of can or tin is grinding.. and the engine vibrates heavily and felt the body shaking big time over 2500rpm... and ive been feeling this power loss for almost a week... could it be a spark plug issue?? Or bad spark plug wires?? Or might the distributor cap be broken or smth?? N.B: oil pressure and temperature normal at all time.
The freaky thing is that noise i heard from the middle part of the jeep..what could possibly be? I apreciate all coments and advices.. thanks.

CCKen

If you have an auto transmission it sounds like the flex plate has come unglued or the torque converter has trashed itself.

Vince A.S

U seem right CCKEN ..just check it on youtube too its a comon problem on xjs.. ill check it

Vince A.S

But the vibration when over 2500rpm would it be from a misfiring issue?

CCKen

Yes, but what's causing the misfire.....


Check the flexplate for cracks and security of the flexplate to TC attach bolts.

Vince A.S

So i spent my day at the mecanic shop... installed new champion spark plugs and new autolite pro-fit spark plug wires..and.. back to power, that reduced even 20% of the vibration...then about the noise i had a broken cross yoke on the driveshaft.. so i changed both cross yokes..and guess what.. no more noise no more vibrations no more nothing..couldnt believe that yoke would make such a massive vibration .. heh..now am happy

t.mcginley.jr

Good to hear you resolved it. Anything that makes the driveshafts, or anything in the drivetrain for that matter, out of alignment/balance will cause vibration.

Vince A.S

Indeed.. i still have the caster adjustment.