HDJ80 undiagnosed "knock" (3 Viewers)

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Mine has the exact same noise. 92 auto 1HDT.

Happens a couple seconds after startup.
Goes away with increased RPM
Quieter when in neutral or park
Sound is coming from inspection hole at bellhousing.
Not sure if someone mentioned this but very rarely the sound will completely disappear, but will quickly come back the next time I drive it.


I'm not sure if it was there before or after my full engine rebuild (7000kms old) but it is driving me nuts and I'm questioning whether the mechanic has stuffed up at some point.

If anyone has any information on this I'd be very grateful!

In your case it might be flex plate bolts. They need loctite or they can potentially come loose and become noisy as the plate moves back and forth against the torque converter. They can be checked through the inspection hole.
 
In your case it might be flex plate bolts. They need loctite or they can potentially come loose and become noisy as the plate moves back and forth against the torque converter. They can be checked through the inspection hole.

Yep already done that. They were all tighter than spec. I'm considering paying the mechanic to pull the transmission back from the engine to eliminate the possibility all together.

I've also read on other forums that sounds like these are common with these engines...

I wouldnt mind the sound so much if I knew 100% it wasn't apart of the engine, which only has a few months warranty left on the rebuild.
 
Yep already done that. They were all tighter than spec. I'm considering paying the mechanic to pull the transmission back from the engine to eliminate the possibility all together.

I've also read on other forums that sounds like these are common with these engines...

I wouldnt mind the sound so much if I knew 100% it wasn't apart of the engine, which only has a few months warranty left on the rebuild.

Mine has a metallic clicking noise from the bellhousing area after a fresh oil change, but it has kind of went away as the oil got some miles on it. Your noise is different than mine, more of a thudding than the high pitched tick that I've heard on many of these motors. FWIW.
 
I’m not familiar with Toyota diesel’s, but I was a diesel mechanic in the coast guard. That does not anything related to the transmission to me. I would suspect a worn crank bearing or installed incorrectly and something is not being oiled properly. You pulled the pan on it and checked the lower end??
 
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This may be a long shot but...
Have you tried timing your injection pump? If the timing of the piston coming up is too ahead or far behind when the ignition takes place it can make the engine sound louder than normal. I just timed my IP and it quieted my HDFT considerably. Surprisingly so actually. I set it to the high end of Factory spec per @Rock40.

Just throwing it out there. When these trucks(or engines) arrive in North America who knows what has been done to them (or not).

Hope you figure it out.
 
This may be a long shot but...
Have you tried timing your injection pump? If the timing of the piston coming up is too ahead or far behind when the ignition takes place it can make the engine sound louder than normal. I just timed my IP and it quieted my HDFT considerably. Surprisingly so actually. I set it to the high end of Factory spec per @Rock40.

Just throwing it out there. When these trucks(or engines) arrive in North America who knows what has been done to them (or not).

Hope you figure it out.
 
Yeah the pump has been timed recently to try and resolve the issue but everything was spot on.

I have just had the oil sent away for examination and they found no signs on wear.

It has just had a new crank put in due to the harmonic balancer turning on the keyhole after the resbuild and the sound was there before the new crank so I find it unlikely it's coming from anything bottom end related, I would at least expect the sound to be different if it was related.

I guess at this point in time I will keep driving it and monitoring it and hope nothing goes bang outside of the warranty period ending in a couple months.

I will update this post if I find the problem. 👍
 
I’m looking at replacing my pump at this point in time. Mine was definitely not Flex Plate related. It continued making the same noise after I swapped an H151 in place. I have not ruled out simple delivery valves, but I do not have much assurance that the previous owner had a reputable shop rebuild the IP as I received paperwork documenting the original rebuild failed within 2 months from the shop.
 
Yeah the pump has been timed recently to try and resolve the issue but everything was spot on.

I have just had the oil sent away for examination and they found no signs on wear.

It has just had a new crank put in due to the harmonic balancer turning on the keyhole after the resbuild and the sound was there before the new crank so I find it unlikely it's coming from anything bottom end related, I would at least expect the sound to be different if it was related.

I guess at this point in time I will keep driving it and monitoring it and hope nothing goes bang outside of the warranty period ending in a couple months.

I will update this post if I find the problem. 👍

Man, pretty hard to believe it could be bottom end related if it was present before and after a crank replacement, nothing would remain untouched doing that job. I would get under the truck on a creeper, and with it running, touch the end of a mechanic's stethoscope to everything underneath, I mean everything. Oil pan, bell housing, trans pan, injection pump, front of the block, head, manifolds, turbo, etc.
 
Did you end up finding the problem? Have the exact same sound with my 80. 1hdt knocking on where the inspection hole was. Rebuilt the pump too last month. Will try injectors next but previous owner did them but might not be 100%
 
It doesn’t “knock” immediately, a few seconds into running it starts. It is also blowing a lot of white (unburnt fuel) smoke now.
I’m leaning towards a bad IP, possibly bad delivery(s) valves.


Sounds more like bad timing to me or weak injector springs .
 
Injectors were rebuilt by a highly reputable source. The timing was checked 3 times. The IP is getting replaced next weekend with a known sound IP. If everything clears up, I will get my IP rebuilt and be back on the road.
 
Sweet mine had the same knock maybe not as pronounced as yours, replaced the injectors today it’s a lot quieter now. Still a little bit noisey but it’s definitely better. Thoughts on this compared to other 1hd-ft’s



Sorry new here don’t know how to post vids
 
Sweet mine had the same knock maybe not as pronounced as yours, replaced the injectors today it’s a lot quieter now. Still a little bit noisey but it’s definitely better. Thoughts on this compared to other 1hd-ft’s



Sorry new here don’t know how to post vids

That sounds just like my 1hd fte. My motor has just come off of a 16k rebuild and that sounds identical. Maybe slightly less noise, but the fte has a heap of factory installed insulation.
 
Just thought I'd give an update on this post...

Still the same noise, nothing has changed and no other symptoms have come up. Have probably driven Around 8000kms.

Annoys the s*** out of me though. Will be getting a tune at some point when money permits and will see if that changes anything.

Might just be an early auto 1HDT thing.

IMO the 1HDFT video posted previously does not have the same noise and sounds good to me.

Hopefully someone can shed some light on this at some point! I will make sure to update this post if I find anything new.

Cheers
 
How to you time these pumps? Do you need a specific tool?
They require a special timing tool which attaches to the rear of the IP. You measure the plunger stroke
 
IMO the 1HDFT video posted previously does not have the same noise and sounds good to me.

Ya, @El Perro 's video sounds fine to me as well, no pinging noises.
 

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