Engine Rattle When Idling + 2 Clunks When Accelerating (1 Viewer)

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Feb 21, 2017
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Portland, Oregon
Hi-

I wanted to see if anyone has a similar issue for their FJ80, I have reviewed multiple previous posts but can not seem to a similar issue. I have 91 FJ80 with 165k miles and here is the issue. When driving to work this morning I noticed when idling and driving under 25 mph a small rattle/rotational "plink" sound which I think my be related to a belt that is too tight when I replaced the alternator. But as I started to get the engine warm and get the rig up to 45 mph I began to hear and feel 2 clunks back to back when I would accelerate. I was hoping to get any insight to what would make the rotational plinking sound and if it may be related to the clunking I get when the engine is warmed.

I have noticed that the voltage gauge is swinging between 12 (middle line) when not driving and 14( between top and middle line) when driving. The oil gauges seem perfectly fine. The clunking does not seem to be related to the axle as it doesn't happen when I turn. I looked at my belts and they all seem to be there and not slapping around.

Any thoughts if you had a similar problem would be appreciated.
 
I don't know about the noises, but I'd put "ALTERNATOR" on my Christmas list.
 
Well, that's the only reason for a swinging needle. It's either the alternator or the belt.

Ask @jonheld, he's the 3FE expert.
 
Well, that's the only reason for a swinging needle. It's either the alternator or the belt.

Ask @jonheld, he's the 3FE expert.

I appreciate it Malleus, I had no idea that the swinging needle was an outcome of that.

I'll investigate the issue before I leave work to see if any belts are loose, so @jonheld doesn't get bothered for no reason. :)

Nick
 
I'd pull it off and have it checked. I doubt that's the cause of the noises, though.
 
So I just got home and am inspecting and the clunks happen when I depress the brake pedal about 1/2 of the way and depress it normally. If I depress the brake very slowly the clunking is a lot less noticeable. Any thoughts about the clunk noise would be appreciated.
 
I’m an idiot.... a brake caliper bolt came off

image.jpg
 
Nice catch without wrecking anything!

Most people lock up on the highway and drive home in reverse........
 
Nice catch without wrecking anything!

Most people lock up on the highway and drive home in reverse........
Nice catch without wrecking anything!

Most people lock up on the highway and drive home in reverse........


I drove home doing about 10 mph and used the ebrake. Still seemed very sketchy.
 
It may not have been your fault entirely. The FSM says to replace them when you pull them. There's a lot of torque on them, assuming your torque them properly. Considering the fact that it's a life safety component, and it's pretty cheap, it's hard to make a case to reuse them.
 
Well, that's the only reason for a swinging needle. It's either the alternator or the belt.

Ask @jonheld, he's the 3FE expert.

Good call, also remember the harmonic balancer could be shearing from the crank pulley at the rubber bonding, paint a white line from outer to inner across the two. Switch on ignition and all electrical loads, lights HRW, heater blower, wait a couple of minutes and start the motor, rev it a few times, screeching brought on by a hard working alternator means loose belts, or tight belts that are worn.

Then shut it down and see if the white line is still across the pulleys, if not replace the crank pulley/harmonic balancer assembly.

Regards

Dave
 
It may not have been your fault entirely. The FSM says to replace them when you pull them. There's a lot of torque on them, assuming your torque them properly. Considering the fact that it's a life safety component, and it's pretty cheap, it's hard to make a case to reuse them.

Thats good to know. I am fairly certain i torqued them down correctly but have always reused the bolts....

I did buy new ones and will put this on my check list for long haul inpections.
 
Good call, also remember the harmonic balancer could be shearing from the crank pulley at the rubber bonding, paint a white line from outer to inner across the two. Switch on ignition and all electrical loads, lights HRW, heater blower, wait a couple of minutes and start the motor, rev it a few times, screeching brought on by a hard working alternator means loose belts, or tight belts that are worn.

Then shut it down and see if the white line is still across the pulleys, if not replace the crank pulley/harmonic balancer assembly.

Regards

Dave


Thanks Dave!

I inspected the belts last night and then alternator belt seems to be wearing down and cracking which i believe is leading to my swinging voltage gauge. I'll be replacing those this weekend and will follow up to see if i still have any issues.
 
@nickinportland

A couple of things, don't forget to check the harmonic balancer.

The belts should be replaced in matched pairs. I have found I can buy a pair of belts at the same time, same brand and same outlet.......and they are slightly different lengths, AFAIK Toyota are the only supplier of matched belts, check with @beno for confirmation and supplies.

Finally, seen many times the pivot bolt under the alternator has worked or been left loose, this allows the alternator to move about, ultimately the alternator and lower bracket holes become elongated, this allows the alternator pulley to turn inwards, the result is that even matched pairs of belts will not tension correctly.

Regards

Dave
 
@nickinportland

A couple of things, don't forget to check the harmonic balancer.

The belts should be replaced in matched pairs. I have found I can buy a pair of belts at the same time, same brand and same outlet.......and they are slightly different lengths, AFAIK Toyota are the only supplier of matched belts, check with @beno for confirmation and supplies.

Finally, seen many times the pivot bolt under the alternator has worked or been left loose, this allows the alternator to move about, ultimately the alternator and lower bracket holes become elongated, this allows the alternator pulley to turn inwards, the result is that even matched pairs of belts will not tension correctly.

Regards

Dave
Dave,

This is such good advice. I was planning to go to Napa to pick up a pair of belts but may reconsider with the info you provided. I did notice my pivot bolt is some what elongated from over time, so i will try and replace as well.

Seriously appreciate all the info. Once I get the belts dialed in I will definitely check back.

Nick
 
This is a link to my thread running on 'MUD' for over 7 years, a little down the page you will see the alternator taken off my own car, also on the block is a bracket that the alternator pivots on, the mounting holes also become elongated on this piece as well.

My LC 80 thread.

Regards

Dave
 
This is a link to my thread running on 'MUD' for over 7 years, a little down the page you will see the alternator taken off my own car, also on the block is a bracket that the alternator pivots on, the mounting holes also become elongated on this piece as well.

My LC 80 thread.

Regards

Dave
I appreciate that Dave!
 
Voltage changing with different revolutions is correct but at idle it should hold around 13.8 and increased revolutions it may rise to 14.4, in normal use this is not normally noticeable on the stock gauge.

Regards

Dave.
 

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