Slight idle shimmy and vibration FZJ80 (2 Viewers)

[N8ABLT]

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!

 

[pa40]

vibration

Did you ever solve this problem? I have the issues and looking for a fix.

 

[bajaphile]

Sounds like either a valve issue (worn cam, etc), or even possibly a failing timing chain tensioner. I'd check the easy stuff first like the OP. Unfortunately there is a lot of things which could cause this. I'd do a compression test, try to test all mechanical systems first before diving into the electrical. Just my own personal preference when dealing with something like this.

 

[PFlan80]

I just replaced my exhaust as well with an EMS manifold back system and am having the same bass type vibrations while in gear/drive. Has anyone found the culprit?

 

[andhop72]

I have this same type of problem. It happens right around the 800rpm mark.

 

[Stylo07]

I have this same type of problem. It happens right around the 800rpm mark.

Ditto. Mine happens just above idle and causes my glove box to rattle. It goes away after a good, long drive, when everything is fully up to operating temp (for example, after my work commute of 17 miles and 25 minutes).

This has caused me to wonder that, even though my motor mounts appear to be in fine shape, perhaps the rubber is hardened when cold/room temp and becomes softer due to the heat, thus mimicking the behavior of a properly functioning/new motor mount. I could be way off.

I ordered and received new OEM motor mounts several months ago, but was talked out of replacing them by a Toyota tech.

I'm not overly worried about it because it runs great, just a little buzzy off idle. It's smooth everywhere else.

 

[etarasoff]

I ordered and received new OEM motor mounts several months ago, but was talked out of replacing them by a Toyota tech.

I had the same symptoms as you guys. Solved with new mounts. Check out my post on another thread: https://forum.ih8mud.com/80-series-tech/745325-low-bass-vibration-rpm.html#post8671788

The old mounts were OK'ed by a mechanic, and generally looked fine visually. But once pulled out, the inner rubber was compressed and shot. I'd totally recommend replacing the mounts.

 

[Swannie]

Well, I too have the exact issue as you gents. I just finished replacing all 3 mounts with Toyota parts and unfortunately, same dang vibration.
I also tried running without any belts also, removing thought of issues with the AC, alternator, or PS.
Anyone have more ideas? I haven't tried the timing yet? What does it need to be set to for a 1995 fz80??

 

[scrowley]

^^^80's like a little timing advance. Think I set mine at 7 or 8 degrees advanced. Easy way is to set to 5. Take for a ride. No knock under load.adjust a little more til a little knock then pull it back a couple degrees. Usually ends up around 7. But every truck is a little different

 

[Swannie]

Any thoughts on that actually fixing the problems???

 

[theluckettslad]

Experiencing the exact same symptoms. Anyone have any luck with this? I always figured it was from my aftermarket exhaust.

 

[clubted]

I also have this issue - a vibration I can feel in the floorboards at around 1600 RPM, then shuts off abruptly. First time my mechanic explored it, with a stethoscope no less, they came up with a loose front bumper bolt. Still vibrated. Next just tried a new distributor, also didn't work but fortunately covered costwise. Going back in this week. It seems worse going uphill under acceleration, sometimes I can actually hold it so the vibration is constant, oddly only happens in first gear.

 

[MoCoNative]

Anyone find a definitive answer to this issue. Dealing with a 97 FZJ80, 191,000 miles. It is my wifes daily driver, this shakes the floor boards, vibrate the truck, sound like a horrendous sound under the seats is getting more common she says. When she takes me out to hear it, of course it is sporadic enough that we can't get it to do it. I have heard it though and I can get it to do it right around the 1800 RPM mark when going up a steep hill, or about stalling the truck right there at the torque convertor lock up point. She says it does it a lot after coming out of a turn, or when downshifting on a steep hill. It just comes on hard and goes away, it is not sort of there. Does not do it when free revving.

Second sound it sometimes produces is a horrendous grinding type sound after startup and backing out of the garage, like something underneath is being ground up, or a heatshield for the exhaust has just come loose and is like bouncing, rattling around under there, then it will just suddenly go away.

I first thought maybe it was something rubbing or making contact, looked the truck over hard this spring, could not find anything. Exhaust is good, no vibes there, remounted it all a while ago as all the mounts had torn loose. Had a rust hole in the "Y" pipe, took that all off and patched it, still good, fixed heat shielding issues there.

I read some accounts of this sound as a spindle bushing spinning, but I can get it to do it while almost stalled in a ditch or similar circumstance, so that is not the front end, as it is not turning. What kind of sounds can come from a failing viscous coupler, or are there transmission issues that can do this, or torque convertor.

Really stumped on this one.

 

[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.

 

[Irish Reiver]

What do you mean by "I get a vibration in the cab"?
- What tests have you done?
- Any codes?
- What RPM do you experience the vibration - does it build and steady out or does it just get worse as the RPM increase?

A vibration that causes the glove box and dash to vibrate is far from normal.

 

[robnicko]

Anyone find a definitive answer to this issue. Dealing with a 97 FZJ80, 191,000 miles. It is my wifes daily driver, this shakes the floor boards, vibrate the truck, sound like a horrendous sound under the seats is getting more common she says. When she takes me out to hear it, of course it is sporadic enough that we can't get it to do it. I have heard it though and I can get it to do it right around the 1800 RPM mark when going up a steep hill, or about stalling the truck right there at the torque convertor lock up point. She says it does it a lot after coming out of a turn, or when downshifting on a steep hill. It just comes on hard and goes away, it is not sort of there. Does not do it when free revving.

Second sound it sometimes produces is a horrendous grinding type sound after startup and backing out of the garage, like something underneath is being ground up, or a heatshield for the exhaust has just come loose and is like bouncing, rattling around under there, then it will just suddenly go away.

I first thought maybe it was something rubbing or making contact, looked the truck over hard this spring, could not find anything. Exhaust is good, no vibes there, remounted it all a while ago as all the mounts had torn loose. Had a rust hole in the "Y" pipe, took that all off and patched it, still good, fixed heat shielding issues there.

I read some accounts of this sound as a spindle bushing spinning, but I can get it to do it while almost stalled in a ditch or similar circumstance, so that is not the front end, as it is not turning. What kind of sounds can come from a failing viscous coupler, or are there transmission issues that can do this, or torque convertor.

Really stumped on this one.

'I can get it to do it right around the 1800 RPM mark when going up a steep hill, or about stalling the truck right there at the torque convertor lock up point'

so youre referring to a vibration at this point whilst driving along and not in P or N stopped?

if yes, id be checking the slip yokes on your driveshafts. I had a similar vibration a few years back and solved it by removing the rear DS and separating the slipyoke, cleaning and re greasing with Moly grease. My symptoms were at about 50-70kph under load a vibration that shook the car and went away when accelerator backed off
upon horoughly cleaning the slip yokles of all old grease and reassembling the vibe has completely dissapeared. there was some old 'hardened' grease in there and I think that is what caused my vibration.
Also, check uni joints for lateral movement

I went through the whole driveline before figuring it out, front & rear axles, cv repack, wheel bearings, auto trans fluid flush, transfer case flush, checked all engine & tranny mounts, shock mounts etc and it ended up being the rear DS slip joint with old hardened grease......

 

[MoCoNative]

robnicko, I will check the driveshafts more thoroughly. They seem good, but they are all original u-joints. This is occurring while driving, often times during acceleration or under a load. This vibration is very intermittent, hit or miss, random, it will not do it on command and does not happen constantly is why it is so odd to track down. Plus being the wifes rig, I just don't drive it on a regular basis, so it never seems to do it for me like it does for her.

I can get it to do it almost stalled out, so the driveshafts would be barely rotating at that point???

I'm planning on changing the transmission filter and fully flushing the fluid this weekend. I have not done anything with it in 75,000 miles. Before that the PO was doing the drain and refill thing a few times. I'm speculating maybe something is hanging in the tranny??? Not an auto expert.

I will be looking at the front end again soon, rotors are slightly warped, so I'm going to swap them out. Had them turned about 30,000 miles ago, but they did not last. Should have just gone for new then.

 

[maximus79]

Any updates after looking at the front end? Would like to hear what fixed it

 

[Alexbv]

What do you mean by "I get a vibration in the cam"?
- What tests have you done?
- Any codes?
- What RPM do you experience the vibration - does it build and steady out or does it just get worse as the RPM increase?

A vibration that causes the glove box and dash to vibrate is far from normal.

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.

 

[Greyota]

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.

Alex,
Did you ever come up with an answer to this? Same issue here.