Slight idle shimmy and vibration FZJ80

[Sandy Cruiser]

Harmonic balancer? The rubber on mine was dry rotted pretty bad and rubbing the oil pump cover. If the engine mounts are shot there is a good chance the rubber on the balancer is shot too.

 

[Greyota]

Harmonic balancer? The rubber on mine was dry rotted pretty bad and rubbing the oil pump cover. If the engine mounts are shot there is a good chance the rubber on the balancer is shot too.

View attachment 3159600

That's interesting. I did my oil pump cover gasket earlier this year and don't recall any issues with the rubber on my HB.

 

[Sandy Cruiser]

That's interesting. I did my oil pump cover gasket earlier this year and don't recall any issues with the rubber on my HB.

Just spit balling. When I replaced my motor mounts and HB the engine idle smoothed out. Idle can still feel a little off when running AC but I just chock that up to age.

Just for reference my fzj80 has 250k miles and has been spending half its life around salt spray which takes a tole on rubber parts.

 

[Greyota]

I replaced the transmission mount, but haven't done the motor mounts yet. I also thought about the body mounts, as they are likely just as degraded.

However, I really think somehow this is exhaust/transmission related. It got immediately better after I replaced the 3 exhaust cushions, but then reverted back to vibrating again, and that had me scratching my head for sure.

 

[Daveinfl33777]

Long time reader, first time posting. I have a 97 LX with 159000 miles. I think I have one or two problems with my LX. The first problem is what I am going to call a slight shimmy while at idle. Cold or warm. More noticeable when warm and idle is around 650 rpms. It will idle normally for a few seconds, then have a slight shimmy, idle normally for a few more seconds, then a slight shimmy, and so on and so forth. No rhyme or reason. It happens when the vehicle is in gear or park\neutral. It is not felt or noticed while driving. This problem seems to be more pronounced after the vehicle has been started and shut off numerous times throughout the day.

The next problem could be related to the first(but I doubt it), since it started around the same time. It is a engine related vibration or hum, which I will compare to a deep bass vibration from a stereo, which resonates through the engine compartment, into the foot feed and floorboards and into the cabin. Both the tranny and transfer case shifters vibrate, more so with the transfer case shifter. It only vibrates/hums when the vehicle is in gear, and is rpm sensitive. It is also loud. Meaning it sounds like I have an aftermarket exhaust(like a turbo muffler) under it. Again, it sounds normal when in neutral/park. Peak vibration/hum is around 1600-1900 rpm. It seems like it is more noticeable just after starting and putting into gear, then warm. Again, it is exhasberated when the vehicle has been turned on and shut off multiple times durning the day.

With that being said, what I have done...New plugs wires, cap, rotor. I have sprayed a fine water mist above the coil--no results. Sprayed brake clean above the intake--no results. Half assed cleaned the intake inlet( did not look all that bad) --no results. Checked the intake snorkel for cracks, and checked vacuum hoses--nothing. Ran Sea Foam thru it. Put a new stock muffler on it(that was bad, leak towards the rear) It seem to be even more loud with the new muffler on it. When I had it in the shop, the tech checked the motor/tranny mounts, which if I can trust his judgement, are OK. Added two more exhaust hangers, but the rest of the exhaust is original. It feels and sounds like exhaust when the vehicle is in gear, but that theory gets tossed after revving it while in neutral or park. No check engine light.

Any insight would be appreciated!

I have the exact same issue with the shimmy at idle felt randomly intermittently...it is felt through the seat/floorpan and is more of a shake than a vibration.

Have you fixed this problem?

Do your rpms change when this happens? My rpms stay the same but I don't know if it could still be engine related and just an ever so slightly out of balance engine whether it be from a fuel injector not injecting as much fuel as other cylinders etc....

 

[Daveinfl33777]

Harmonic balancer? The rubber on mine was dry rotted pretty bad and rubbing the oil pump cover. If the engine mounts are shot there is a good chance the rubber on the balancer is shot too.

View attachment 3159600

What were your symptoms with this HB? I am thinking my HB is causing my problems but my problems are INTERMITTENT and I am not sure that a bad balancer or bad mount would cause INTERMITTENT shaking....my HB isn't in the greatest shape and my mounts seem to be slightly cracking as well....

 

[Sandy Cruiser]

What were your symptoms with this HB?

Vibration at various RPM's. It can very depending on the HB. I had a buddy that had really bad idle and vibration on a out board and it ended up being the HB. But that engine mount looks rough, is the rubber soft or hard as a rock? You could just be getting excess engine vibration through the motor mounts.

 

[Daveinfl33777]

Vibration at various RPM's. It can very depending on the HB. I had a buddy that had really bad idle and vibration on a out board and it ended up being the HB. But that engine mount looks rough, is the rubber soft or hard as a rock? You could just be getting excess engine vibration through the motor mounts.

I never tried to feel it but I'd imagine it is hard....it is 18 years old....and most of the vehicles life has been here in Florida

 

[Alexbv]

Had a bad engine mount. Replaced it and it went away. It has been a couple years.

 

[Alexbv]

Anybody figure it out? My lx450 runs smooth and idle is pretty steady at just over 650 but I get a vibration in the cab that vibrates the glove box and dash.

Man it has been a while since I’ve been here. Too many things going on. Haven’t even driven the cruiser in all this time.
I meant vibration in the cab. It happens when stopped with the shifter on “D” Engine idles at just over 650rpm and there are no engine codes.
It happens pretty much when I come to a stop and it is continuous unless I shift to P, N or if I give it some gas.

Engine mount was bad. Replaced it and it has been fine since