Diesel Nailing? Missing Injector seats. Possibly related? (the sky was falling - but it wasn't)

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JDM Journeys

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I bought my hzj77 three years ago almost to the day. Ever since day one it's had a noise that I haven't been able to *nail* down. (foreshadowing perhaps?)

Its most noticeable in the morning when cold and you accelerate to about 2200rpm. Sometimes I can hear it subtly through the rev range, other times it seems less noticeable once it reaches operating temp but always only under load

It's what I'd describe as a harsh rattle. Hard to pinpoint exactly where beyond "the engine" lol. I've used my stethoscope with no real results. Really noticeable accelerating next to a guard rail. Gear choice doesn't seem to matter. 4wd doesn't change it. Exhaust was checked. No signs of wayward soot anywhere... IP was recond'ed.

I had finally accepted the noise as part of the truck. The 1hz/1hdt crank flex or whatever they call it...

I was listening to it again with the radio off the other day on the way to work when I started thinking back to when I replaced the injectors. I got new seal gaskets with the new injectors, but I don't recall any brass seats. I looked back through pics and no sign of them. And I don't ever remember seeing the seats when I pulled out the old ones... the noise was there before and after the new injectors.

So here's my question after the world's longest, most rambling preamble...

If there were no injector seats, wouldn't that put the injectors closer, and thus cause diesel nailing at certain rpms?

I have them on order so I don't want to pull the injectors twice but I'll be able to confirm soon enough whether there is a seat in there or not. But does my theory sound possible?
 
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I have to thank @OGBeno for the knowledge I have on this. My 14B is set up with steel seats, then a rubber seat washer for the injectors. They were about .90 cents at the Toyota dealer. They looked like flat washers. This was all new to me but it made a big difference
 
You're ruled out an exhaust leak?
 
The direct injection injectors are different from the IDI. My 15B-T has flat brass (I think) seats and rubber dust seals on the body. The IDI injectors on my 3B have crush washers on the seat (which indeed will tend to stay in the head when removed). They also have a re-useable seat. If either of these were missing you would most likely get diesel creeping up the threads of the injectors. Not a bad idea to pull them all and replace the crush washers, they are very cheap.

My suggestions would be a hairline crack in the exhaust manifold, or a noisy valve. Or could it be something external to the engine; an idler pulley bearing, alternator bearing, clutch release bearing, AC compressor clutch bearing?
 
The direct injection injectors are different from the IDI. My 15B-T has flat brass (I think) seats and rubber dust seals on the body. The IDI injectors on my 3B have crush washers on the seat (which indeed will tend to stay in the head when removed). They also have a re-useable seat. If either of these were missing you would most likely get diesel creeping up the threads of the injectors. Not a bad idea to pull them all and replace the crush washers, they are very cheap.

My suggestions would be a hairline crack in the exhaust manifold, or a noisy valve. Or could it be something external to the engine; an idler pulley bearing, alternator bearing, clutch release bearing, AC compressor clutch bearing?
I did all the injector seats, seals and fuel rail washer thingies on the weekend, and yes, the old ones were all there. My newish (25k kms) injectors had a little carbon on the tips but were generally fine. The old seats looked okay, the seals had some carbon. Seat of the pants drive seems a little snappier (for a 1hz) but probably placebo effect? 😉

PXL_20231014_183557004.jpg


I also tightened up a rattly exhaust mount. No real change in the rattle, but at least those things are done.

Exhaust manifold is still on my list, as well as valve train. I did do the valve lash in summer but that wouldn't magically make a noisy valve quieter.

The other things have been ruled out by elimination via belt removal, etc. Except for clutch which is also on the list. Wondering about pressure plate? The clutch is getting that worn feeling but I'll put it off a little longer. A buddy and I just went in on a trans jack, so I guess it's getting a little closer to clutch time?

Thanks for the input all!
 
Soemtimes these noises are just part of the engine's operation I think.

I have a 3RZ-FE in a Hilux Surf (which I think is a pretty amazing engine and rather underrated) I fully rebuilt it and yet there is still an odd out-of-phase clack coming from around the flywheel area now and then. There are quite a few reports online of the same, from new and old engines, and I never read anything from anyone who had really fixed it, and neither anyone who traced it to any engine problem or failure. It just seems to be an odd noise that a 3RZ makes. Perhaps what you are hearing is just a 1HZ noise!
 
Soemtimes these noises are just part of the engine's operation I think.

I have a 3RZ-FE in a Hilux Surf (which I think is a pretty amazing engine and rather underrated) I fully rebuilt it and yet there is still an odd out-of-phase clack coming from around the flywheel area now and then. There are quite a few reports online of the same, from new and old engines, and I never read anything from anyone who had really fixed it, and neither anyone who traced it to any engine problem or failure. It just seems to be an odd noise that a 3RZ makes. Perhaps what you are hearing is just a 1HZ noise!
You're not wrong there. There are plenty of reports of "the 1hz/1hdt noise" too. I've read of crank flex and all kinds of other theories. Dunno if mine is just part of this engine lore or not? Ah well... I'll keep doing maintenance and upgrades as needed and maybe something will magically quiet it down? 😉
 
You're not wrong there. There are plenty of reports of "the 1hz/1hdt noise" too. I've read of crank flex and all kinds of other theories. Dunno if mine is just part of this engine lore or not? Ah well... I'll keep doing maintenance and upgrades as needed and maybe something will magically quiet it down? 😉
When you have exhausted all options and theories, maybe try incense in the garage and some meditation. Probably won't help the land cruiser any, but it might help soothe your soul and cause a new epiphany that you could try? 😜 :cheers:
 
If it makes you feel better, my 2008 HZJ76 feels louder than the 2000 HZJ78. Not sure if it’s true or not, haven’t measured with a dB meter yet. But I probably will. 😁 😂
 
If it makes you feel better, my 2008 HZJ76 feels louder than the 2000 HZJ78. Not sure if it’s true or not, haven’t measured with a dB meter yet. But I probably will. 😁 😂
I do not doubt this, as with the additions to the troopy, you have insulated the rear floor against road noise. I found adding the kilmat to the floor in my 76 made a notable difference. Might be in the wheelhouse for future upgrades?
 
turbo will fix all that....... 😁
 

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