12 HT Engine Vibration

[Archer]

First post to the site but have visited numerous times, the best Cruiser information out there. First Cruiser in 1991 - 1988 FJ62 was daily driver until last year when I purchased my "new" diesel Cruiser. 1987 HJ 61... diesel in the way to go. Still have the FJ, old friends are hard to part with.

Getting down to business I need help for what I hope is a minor problem with the diesel engine. Noted a engine vibration that starts out around 1200 RPM and peaks at 1500 RPM and then smooths out to the diesel purr from there up. 1500 rpm is where the turbo kicks in so I figure it may have something wrong with it. Engine has 236K km and runs great otherwise. Does not blow black smoke and the vibration is there when parked or driving so nothing to do with the drive train.

Ran two tanks of injector cleaner (1 Power Source? 1 Sea Foam) no change. Changed air filter and fuel filter no change. Diesel tech from my work (phone conversation) suggested the turbo needs rebuilding, my mechanic who lives and breathes Cruisers says no!

I'll open the floor to suggestions.

 

[roscoFJ73]

Is the vibration making the whole vehicle vibrate or just in the steering column,floor etc?
Have you checked the engine mounts? Even if they are not broken they may have gone soft.

Also you can not expect a diesel to be as smooth and quiet as a 3F,they are almost silent when tuned correctly.

 

[GM60]

I agree about checking the engine mounts.
Also check the transmission mount and check that the exhaust system is not touching the body or chassis and that its mountings are in good order.
You could also check drive belt condition and water pump bearing play.
Hope you get it sorted.

 

[Ron R]

If all suggested above fails in finding the problem, maybe an injector inspection might be due. (235 K km's!?)
The injectors don't necessarely have to be bad but there could be one of them being off-limits regarding opening pressure.
The absolute openingpressure of injectors is not as critical as being them all of the same value.
The better they are 'synchronised' in terms of openingpressure the smoother the engine will run.

 

[2rivers]

FWIW ours has a wierd "shimmy" / vibration whatever right around 1100 - 1200 (maybe more cant remember offhand) rpms. My 2 cents is that yours is the same and you have nothing to worry about these motors are solid..

 

[mac]

Two things:

If injectors have not been serviced to your knowledge- have them tested.

Also, a vibration can result from a harmonic balancer not doing it's job. Closely inspect it (if you can get your eyes in there) and look for degradation of the rubber core.

 

[Mountain Goat]

Are you sure that you are not lugging the engine? Diesels do not have as wide of a power band as gas engines. My 12H-T does this as well, but only when I try to accelerate in a gear that is too high.

 

[roscoFJ73]

The better they are 'synchronised' in terms of openingpressure the smoother the engine will run.

The diesel shops called it "flow tested" or "flow matched" here.Its a standard service from reputable shops



Archer,you may also want to check the harmonic balancer or the key that holds them on.

I havent inspected a 12HT that closely but I think you would have to remove the belts and balancer for an inspection.
Do it after all the other things have been checked.

 

[Ron R]

The diesel shops called it "flow tested" or "flow matched" here.Its a standard service from reputable shops

Yes, well, ehh, english is not my native language (if you have not noticed yet ;p;p)
So I have to find the right wording every now and then. Apart from that, certain expressions cannot be found in dictionaries and sometimes different expressions are used for the same job.

Off course the 'flow match" should be standard procedure for new or rebuild ones, but when injectors get older.......

Archer,you may also want to check the harmonic balancer or the key that holds them on.

I havent inspected a 12HT that closely but I think you would have to remove the belts and balancer for an inspection.
Do it after all the other things have been checked.

I second that.

 

[troopie]

My 12HT did the same thing after a rebuild at a reputable shop. Everything was done to the engine exept the injection pump. Well that part was the problem, i took it off and brought it to a diesel shop. 275 Euro's later i have a very smooth running engine and got around 30-35 more horses out of it. Might as wel tweak the pump while it's out. (not necesery but fun nonetheless)

I'm not saying that that's your problem, but it could be.

HTH
Mark