FZJ80 "Pennies in A Tin Can" Off Idle Under Load

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Cheap Cruiser

Cheap Cruiser

Joined
Apr 17, 2017
Threads
4
Messages
14
Location
Philadelphia, PA.
1996 FZJ80
Engine: 1FZ-FE
255,000 Miles on Body
Unknown Miles on Engine: Engine replace by previous owner with LX450 1FZ-FE
I have owned the truck for 1.5 years with no other engine issues.

I am a bit stumped. I am getting a loud rattle in or around the front of the engine. The noise resembles pennies being shaken in a tin can. This noise only occurs when the:

Engine is warmed up
The truck is in drive
When the truck is under load @1200-2500rpm Pretty much right off idle
Speed does NOT induce the noise. Only engine RPM (it will make noise at 35 MPH if load is applied after coasting)
Noise does NOT increase in frequency as RPM increases
Nose can be made with truck in park, foot on brake, and gas peddle pushed to 1500rpm

The penny sound only occurs between 1200-2500ish rpm. Pretty much as soon as you are off idle in drive it starts to make noise. If under heavy load it will go away (sort of) but will start making a louder “bang” type noise. The noise will not increase in frequency as the truck revs up. I have taken the drive belts off while the noise was going on and in drive it still makes the noise with no difference in sound. All of the accessories, pulleys, and water pump feel fine with no noise, griding, or rough spots.

Within the past 6 months:

Engine Tune Up:
OEM Plugs, Cap, Rotor
OEM Wires
OEM Valve cover gasket
OEM Idler Pulley (Alternator)
Mahle Filters
Checked/Tighten engine mounts

I am just hoping a more seasoned FJZ80 warrior or mechanic have run into this before. I have read articles on MUD about timing chain guides causing issues but it seems it pre-dates the 1FZ-FE. I'm just wondering if I am looking at possible timing chain issue/replacement or possible bottom end issues. To be honest, with a head off service I am halfway to a full engine rebuild either way.

Other than the noise in the engine off idle under load it idles fine, is wispier quiet, has no power loss and is a dream to drive. Hell, I could almost balance a quarter on the dam 1FZ!

I hope you guys could help point me in the next direction to look. Thank you all!
 
Last edited:
Cheap Cruiser said:
1996 FZJ80
Engine: 1FZ-FE
255,000 Miles on Body
Unknown Engine: Engine replace by previous owner with LX450 1FZ-FE
I have owned the truck for 1.5 years with no other engine issues.

I am a bit stumped. I am getting a loud rattle in or around the front of the engine. The noise resembles pennies being shaken in a tin can. This noise only occurs when the:

Engine is warmed up
The truck is in drive
When the truck is under load @1200-2500rpm Pretty much right off idle
Speed does NOT induce the noise. Only engine RPM (it will make noise at 35 MPH if load is applied after coasting)
Noise does NOT increase in frequency as RPM increases
Nose can be made with truck in park, foot on brake, and gas peddle pushed to 1500rpm

The penny sound only occurs between 1200-2500ish rpm. Pretty much as soon as you are off idle in drive it starts to make noise. If under heavy load it will go away (sort of) but will start making a louder “bang” type noise. The noise will not increase in frequency as the truck revs up. I have taken the drive belts off while the noise was going on and in drive it stills make the noise with no difference in sound. All of the accessories, pulleys, and water pump feel fine with no noise, griding, or rough spots.

Within the past 6 months:

Engine Tune Up:
OEM Plugs, Cap, Rotor
OEM Wires
OEM Valve cover gasket
OEM Idler Pulley (Alternator)
Mahle Filters
Checked/Tighten engine mounts

I am just hoping a more seasoned FJZ80 warrior or mechanic have run into this before. I have read articles on MUD about timing chain guides causing issues but it seems it pre-dates the 1FZ-FE. I'm just wondering if I am looking at possible timing chain issue/replacement or possible bottom end issues. To be honest, with a head off service I am halfway to a full engine rebuild either way.

Other than the noise in the engine off idle under load it idles fine, is wispier quiet, has no power loss and is a dream to drive. Hell, I could almost balance a quarter on the dam 1FZ!

I hope you guys could help point me in the next direction to look. Thank you all!
Click to expand...
I have a similar problem but mine gets louder when on gravel roads and it sounds like rocks in the fender. I have searched for loose parts banging on sheetmetal and everything seems solid. I can sometimes hear it on the street and definitely hear it going over railroad tracks or large expansion joints. I try to ignore it but everytime we go camping, it is a noticeable reminder that I need to find out the source of the noise.
 
Are your exhaust manifold heat shields cracked? Mine had fatigue cracks around the bolt heads (3 on each IIRC) and made a rattle until I removed them.
 
I had what I interpret to be the same sounds....similar to pinging / knocking. Rapid fire, low rpm.
Bought a used maf / vaf....No more problems. Been over 1yr.
‘94FZJ
 
Check the heat shields on the down pipe on the way to the cat. These are the ones that are just under the floorboard. Mine also developed a crack or two in there and it started to rattle like that. I put a hose clamp or two to snug it down. No issues since.
 
Yup ... do you have sliders? If so, check the cat clearance. My cats rub on the slider guard. I keep temp fixing it, but will now find a more permanent solution.
 
A few possibilities I have experienced (there's a reason I call it the clunker):

Exhaust vibrating against frame or touching something it shouldn't

Muffler contacting driveshaft (will be obvious if you look)

Radiator fan/shroud misaligned and contacting each other.
 
I would look at the following (in order):
1) Exhaust heat shields on the manifolds rattling / loose
2) Exhaust heat shield on down pipe under RF fender rattling. Install two hose clamps over it. One high, one low.
3) Exhaust heat shield above catalytic converters. tap around to find it. Then install large hose clamps or fix the broken shield.
4) Catalytic converter is failing and has the internal plates comes loose. They rattle at various frequency RPM's. Eventually, one will block the discharge and your temps will rise and power will drop off.
 
Not that i think this is it, cause i doubt it, but check your coil springs to bump stops in the front. Mine rub and it is just in the right position to click or tick with the slightest of axle movement. Like i said, very long shot, but just trying to give you ideas
 
WOW! Thank you for all of the great suggestions. I did check the exhaust manifold covers and one of the mounting bolts seems to have cracked on the shield. I will remove the cover and see if i am getting noise. I will also attempt to record the noise if it is still present.
 
SOLVED: I fixed my problem and didn't even know it. The rattling on gravel roads was from the dust/mud shields that cover the rotors.

The PO bent the shields on both the driver and passenger side when he jacked up the truck by the rotor. I found the bent shields when I was removing my control arm mounts. I took my angle grinder and cut 1.5" off the bottom of the shields. It's been about a month since I cut the shields but just yesterday I went to the trails and rode the gravel paths. I immediately realized how quiet the truck was on gravel and offroad. We rode the trails all day and I was totally impressed with the silence. Only until I was driving home from the trails did I put 2 and 2 together that the shields were actually banging against the rotors.
 
Cheap Cruiser said:
WOW! Thank you for all of the great suggestions. I did check the exhaust manifold covers and one of the mounting bolts seems to have cracked on the shield. I will remove the cover and see if i am getting noise. I will also attempt to record the noise if it is still present.
Click to expand...

Reviving an old thread, having these exact symptoms. Now that it's in the 100's here in phx, noise is back and loud. Heat shields all seem to be fine but, I will throw some hose clamps on and see if it changes.


Anyone else have ideas? I read another thread that suggested it could be a fan clutch? Or a timing chain issue.
 
Another revival.. I am getting 1/4-1/2 second of pinging from off-idle to tip in and low rpm, just as OP described. Only when engine is hot/heat soaked, and on warmer days. No solution yet.. also have replaced and serviced most everything external, including new flow matched injectors, plugs, wires, cap, rotor, all new vacuum lines under the intake, new VCV, TVV, etc.

My guess .. carbon build up on pistons? I suppose I need a bore scope for that.
 
Alpine4X4 said:
Fan clutch?
Click to expand...
Maybe. but seems OK. It was replaced probably 5 years/25k ago. roars on startup. 84F today, temps run averaging 193F on the highway with A/C on. Goes to 198-199 on longer slight inclines. Climbed to 215 for a minute while climbing/ off roading. Then hovered around 205-208

EDIT: after reading more on the fan clutch, I think I will just order a replacement anyway to eliminate that concern. Seems the bimetal bits can go bad in that amount of time anyhow.
 
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Brav said:
Another revival.. I am getting 1/4-1/2 second of pinging from off-idle to tip in and low rpm, just as OP described. Only when engine is hot/heat soaked, and on warmer days. No solution yet.. also have replaced and serviced most everything external, including new flow matched injectors, plugs, wires, cap, rotor, all new vacuum lines under the intake, new VCV, TVV, etc.

My guess .. carbon build up on pistons? I suppose I need a bore scope for that.
Click to expand...
Bad knock sensors or wiring harnesses?
 
BILT4ME said:
Bad knock sensors or wiring harnesses?
Click to expand...
I’m going to try this, could it be something that slowly fails? I need to research how the knock sensor actually works.

my timing from the previous owner was advanced off the scale when I checked it, getting that correct really helped but it still happens when it’s heat soaked.
 
Brav said:
Another revival.. I am getting 1/4-1/2 second of pinging from off-idle to tip in and low rpm, just as OP described. Only when engine is hot/heat soaked, and on warmer days. No solution yet.. also have replaced and serviced most everything external, including new flow matched injectors, plugs, wires, cap, rotor, all new vacuum lines under the intake, new VCV, TVV, etc.

My guess .. carbon build up on pistons? I suppose I need a bore scope for that.
Click to expand...
your description very much sounds like light pinging.
How is the oil consumption on your car, leaky valve stem seals combined with the hot weather being experienced in the USA at the moment is a good recipe for light pinging as the oil can ignite. Mine was doing the same in hot weather only before the HG went and the VSSeals were well & truly leaking
does it do it from a cold start?
 
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