FZJ80 Knock or Ticking warm, higher RPM (1 Viewer)

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Aug 16, 2022
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Hey Mud,

SO I've had this sound on my 94 FZJ80 since I picked the thing up 6 months or so ago. When I got the car, it had a misfire and a few other random creaks, and initially it sounded to me like a loose exhaust shield or something similar that could be sorted out as the car was brought back to life. The misfire ended up being a bad injector lead, but after that the car ran perfect - idles fine and I do not feel any loss of power compared to my other 1FZ 80 that runs well.

It makes the sound under these conditions:
Sound comes on around 3k and continues as revs increase
Can sometimes here it slightly when coasting around 2,2-2,300
Can replicate the sound standing still only once engine is warm (video), otherwise it will do it under load around 3k
Originally I thought it was one of my cats starting to break down, but when taking this video the sound gets quieter moving away from the motor even towards the cats

Car has 170k, and doesn't leak anything that might be alarming. There was no metal in the oil with the last oil change, and there really is no noticeable weirdness to how it runs or drives other than that it's making this horrible noise. The funny thing is, my buddy has a 94 with 330k and it makes the exact same sound, but all else the same - runs/drives great too. I read in a couple of Mud threads that people described somewhat similar noises, and it lead them to the power steering pump gear, harmonic balancer wear, engines being out of time, and things like exhaust leaks. But the scenarios seemed to be different.

It's with a reputable LC shop in LA that tells me they think (without having properly diagnosed yet) that it's a broken bearing or something that has come loose in the crank case. But the repeatable conditions and the lack of metal in the oil tells me that miiiight not be the case. I've made the recommendations I said in the last paragraph but their next next thing is a 15 hr diag to pull the valve cover and oil pan and check everything.

SOOO all of that said - has anyone experienced a noise like this under these conditions or can point me in the direction of 1FZ-FE wear points that may cause something like this?


Also - this is my first real tech post here, so my apologies if it's in the wrong place.


Video - 94 FZJ80 Knocking/Ticking Sound
 

baldilocks

Battle Ground, WA
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What about audibility from top to bottom of the engine? Seem as though you didn’t send an oil sample out for analysis so saying there is no metal in the oil might not be true. Have you verified actual oil pressure with a test gauge? Don’t tell us you are running a Wix or Napa gold oil filter….. those have killed a few 1FZ’s due to defects.
 
Joined
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What about audibility from top to bottom of the engine? Seem as though you didn’t send an oil sample out for analysis so saying there is no metal in the oil might not be true. Have you verified actual oil pressure with a test gauge? Don’t tell us you are running a Wix or Napa gold oil filter….. those have killed a few 1FZ’s due to defects.
Thanks for the quick reply! You're right I haven't sent anything off yet, this was much more of visual, feel, and magnet "tests." The next step will be to send something off. The shop that currently has it says that they tested actual oil pressure and it's ok. I luckily have stuck to Toyota parts on this truck, so oil filter shouldn't be causing issues. What sort of defects are the oil filters having that are ruining these engines?
 
Joined
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Messages
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Location
Southern California
What about audibility from top to bottom of the engine? Seem as though you didn’t send an oil sample out for analysis so saying there is no metal in the oil might not be true. Have you verified actual oil pressure with a test gauge? Don’t tell us you are running a Wix or Napa gold oil filter….. those have killed a few 1FZ’s due to defects.
Oh, and the sound is more audible from the bottom of the engine
 

LandLocked93

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Wow that's sounds not good.
 
Joined
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Olathe, KS, USA
My first thought is check timing and knock sensor wiring and sensors themselves.

There are two knock sensors.

It's not uncommon for the wires to get brittle and break.

It sounds your like timing is way too far advanced and the knock sensors are not telling the computer to adjust.
 
Joined
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My first thought is check timing and knock sensor wiring and sensors themselves.

There are two knock sensors.

It's not uncommon for the wires to get brittle and break.

It sounds your like timing is way too far advanced and the knock sensors are not telling the computer to adjust.
That’s interesting. My only thought is that it hasn’t thrown any codes. Is it possible for either knock sensor to be faulty without throwing a code?
 
Joined
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Oregon
It sounds your like timing is way too far advanced and the knock sensors are not telling the computer to adjust.

When the knock sensors are disconnected, the vehicle will be ridiculously sluggish because the ECU won't advance the timing at all. I had the pleasure of experiencing this when I snapped a knock sensor connector off while trying to reach the PHH. Seems unlikely to be the problem since OP says it runs well. (Still worth checking the timing, though, because WTF, gotta start somewhere)

@dshooks maybe a flex plate bolt backing out? Pop the black plastic inspection cover off and see if it gets louder. I can't imagine it would be so load/rpm dependent, though. I've never heard a noise quite like that, I guess I'd start with a mechanic's stethoscope. Then try the usual stuff: run it for a minute with the belts off, and try with the steering pump pulled away from the block.
 
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Just got off the phone with K&H (the shop). Here's the update:

Thank you @gummycarbs I gave them your suggestion as well for flex plate, and they said it is certainly not coming from there.
Pulled power steering pump - no change
And timing is OK

They've isolated the sound to the bottom middle under the block, which is disheartening. The suspect is a failed rod bearing, and they'll be pulling both pans to verify hopefully today. I asked them to try to pull spark plugs one at a time to isolate it to a cylinder. Not that it would matter, but if it is a rod bearing that would at least quiet the noise and make the guess a little bit less of a guess before they get in there.

My thought now is what would cause this crazily over-engineered motor to detonate a rod bearing at 170k?
 
Joined
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Olathe, KS, USA
Just got off the phone with K&H (the shop). Here's the update:

Thank you @gummycarbs I gave them your suggestion as well for flex plate, and they said it is certainly not coming from there.
Pulled power steering pump - no change
And timing is OK

They've isolated the sound to the bottom middle under the block, which is disheartening. The suspect is a failed rod bearing, and they'll be pulling both pans to verify hopefully today. I asked them to try to pull spark plugs one at a time to isolate it to a cylinder. Not that it would matter, but if it is a rod bearing that would at least quiet the noise and make the guess a little bit less of a guess before they get in there.

My thought now is what would cause this crazily over-engineered motor to detonate a rod bearing at 170k?
How about drain the oil to see if the glitter chicks were in there?
 
Joined
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@BILT4ME a miscommunication means the shop hasn’t actually done that yet. Should be happening shortly.

But the car has made this noise as long as I’ve owned it and when I changed the oil a couple of months ago, I didn’t see any glitter or anything and there was definitely nothing major that came out.
 
Joined
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OK folks - the update

Take the oil filter off and rip it open..don't cut it as that will leave glitter, but you should be able to tell from the element inside if it has glitter.

Due to time, I pulled a sample and sent it to Blackstone. The sample very clearly had glitter in it unfortunately..

Report is attached. States high levels of moisture (but not antifreeze) which is interesting, but the oil isn't milky. High levels of aluminum, copper and lead which points towards bearings. Passing it off to Cruiser Tech in Orange County, CA to pull the pan and if they verify that it's the bearings, open discussion about rebuilding.
 

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