[Mohnish]

Getting this very mild, but noticeable, vibration from the engine through rpms 1200 till 1400. Happens even when steady without any gear engaged on increasing / decreasing engine revs through this rpm range, going up and down the rpms, so its definately from the engine.

Checked the belt, the power steering pump, alternator, fuel filter housing etc., all the units strapped onto the engine block are tight. Even checked the exhaust system for a loose fit. So whats left ?

I figure, could it be a fuel adjustment to the diesel pump?
Or the timing chain tensioner is weak?

All inputs welcome...Thanks in advance.

[dadu]

How much has it run??..maybe the engine mounts need a change!!

[Mohnish]

Originally Posted by dadu

How much has it run??..maybe the engine mounts need a change!!

Hi Dadu, forgot to mention, checked the mounts too...they are secure...and its run 43K

[Sideways]

Is it like a metallic vibration sound ?

I wish I had some pictures to explain, but anyhow, I will do my best, see if it helps.

Theres a metal pipe which is attached to the EGR. This pipe is supported with metal brackets. These brackets are not of very good quality and often tend to break with the vibration of the engine. I have already changed this bracket thrice in my jeep. The broken bracket tends to make a noise, but only at or between certain RPM's.

You wont be able to make out by standing in front of the jeep. You willl have to open the hood and stand near the left hand side front fender.

I will try and take some photos opf the area tomorrow.

[DirtyDan]

Some things to check:

1.) Tighten bolts where the exhaust pipe joins the
exhaust manifold.
2.) Check exhaust again underneath for loose heat
shield(s).
3.) Tighten brackets that hold the A/C pipe to the
firewall,
this can rattle big time.
4.) Check water pump.
5.) Check belt tensioners on rubber belts, not just timing
belt.
6.) Check air filter and its metal housing.

[Mohnish]

Originally Posted by Sideways

Is it like a metallic vibration sound ?...
...I will try and take some photos opf the area tomorrow.

Thanks Sideways, but no the sound is not metal to metal. In fact there is no 'sound', its only a vibration and a mild one at that (though annoying). Also have gone under and checked, there is nothing loose.

The vibration something similar to what would happen if you partially restrict the fuel flow to one of the nozzles, hence makes me think of trying a fuel adjustment on the pump with the engine running at that particular rpm.

Will await your photos, to be sure if it isnt what you are referring to...You never know!

[Mohnish]

Originally Posted by DirtyDan

Some things to check:

1.) Will check
2.) All ok
3.) Will check
4.) Could it be the water pump bearing? Hope not!
5.) All ok
6.) All ok

Thanks DirtDan...will post on this as soon as done.

[tsk1979]

Did you check the radiator fan mounts?

[Mohnish]

Originally Posted by tsk1979

Did you check the radiator fan mounts?

Thanks tsk1979...one more to the check list !

May be the nozzles need cleaning ?

[DirtyDan]

Originally Posted by tsk1979

Did you check the radiator fan mounts?

I had the same thought, and the fan itself for a notch or damage causing out of balance.

Also, you might try testing thru that RPM range with the clutch depressed in neutral and then with the clutch depressed but in any/all gears.

[Mohnish]

Originally Posted by DirtyDan

I had the same thought, and the fan itself for a notch or damage causing out of balance...

Yep, good idea to look there...may be remove the belt and run through that rpm range...

Originally Posted by DirtyDan

...Also, you might try testing thru that RPM range with the clutch depressed in neutral and then with the clutch depressed but in any/all gears.

Clutch bearing?

Ok got a long list of things to check out.

Also just spoke with my regular diesel pump 'expert' and he says that its probably only a minor adjustment with the pump running a bit retarded which can be corrected without removing the pump. He's going to have a look at it on Saturday morning. Meanwhile, will check out the list afore mentioned.

Thanks again

Got to mention this here: This is a great site...relief to know there is a place where mild to hardcore tech heads can hook up!!! The amount of knowledge floating around is really awesome.

[RedMM340]

Originally Posted by Mohnish

Getting this very mild, but noticeable, vibration from the engine through rpms 1200 till 1400. Happens even when steady without any gear engaged on increasing / decreasing engine revs through this rpm range, going up and down the rpms, so its definately from the engine.

Checked the belt, the power steering pump, alternator, fuel filter housing etc., all the units strapped onto the engine block are tight. Even checked the exhaust system for a loose fit. So whats left ?

I figure, could it be a fuel adjustment to the diesel pump?
Or the timing chain tensioner is weak?

All inputs welcome...Thanks in advance.

Hi Monish,
It sure sounds like there is some issue with the engine. The diesel pump should not need any adjustment if you are getting full power and acceptable amounts of smoke. Are you getting full power across the entire rpm range?
Some things that I would check with the fuel supply:
Is your diesel pump primed?
Bleed your injector nozzles by loosening slightly and allowing fuel to leak out. This will bleed any slight air that is trapped.

I believe that the non crde motor has a chain type timing belt, so you should get that checked. But the chain style is very durable and should not have any problems at 43k.
Also, the valve clearances should be checked along with the timing chain.

Of course, make sure that your diesel filters, and air filter are clean.

[Mohnish]

Originally Posted by RedMM340

Hi Monish,
It sure sounds like there is some issue with the engine. The diesel pump should not need any adjustment if you are getting full power and acceptable amounts of smoke. Are you getting full power across the entire rpm range?

Hi RedMM340...

Honestly, the vibration is almost negligable, some may not even notice it, I on the other hand am a bit 'picky' & particular...and no, there isn;t any smoke.

I am getting full power across the rpm range, though I do feel the turbo 'kick in' around 1800, a surge of power from then on, kinda nice !!! Is this 'normal' for this engine?

Originally Posted by RedMM340

...Is your diesel pump primed?
Bleed your injector nozzles by loosening slightly and allowing fuel to leak out. This will bleed any slight air that is trapped.

Should'nt I have some sort of starting trouble (which I don't) if there was an air lock in the fuel lines?

Originally Posted by RedMM340

...I believe that the non crde motor has a chain type timing belt, so you should get that checked. But the chain style is very durable and should not have any problems at 43k.
Also, the valve clearances should be checked along with the timing chain.

Yep, I am going to check the timing chain tensioner to negate the possibility of a harmonic vibration.

Regards the valve clearances...I really don't, at this time, want to go that deep into the head...Reason: When you start opening up, you usually end up doing a lot more than intended 'while you in there'!!!

Originally Posted by RedMM340

...Of course, make sure that your diesel filters, and air filter are clean.

All replaced and new.

Will go through the 'easy' list thats been compiled on this thread tomorrow and if unsucessfull, then will have the diesel pump chap look into the timing of the pump.

If none of this works, then will 'live' with it!!!

[RedMM340]

I wish I could figure out how to the multi quotes to answer questions one by one. But I don't so here is my reply:

I have the same motor in my Jeep, but do not notice any vibe at 1200 to 1400 rpm.

The surge in power is normal for a turbo engine, and sure feels good.

You can have slight amounts of air and still start no problem. What I suggested was just a fine tuning to bleed any slight air out. Don't do it unless you feel confident doing it.

Valve clearances are pretty simple to do. Just have to take off the valve cover and stick in a feeler gauge. But honestly, I really doubt that this will solve your problem.

As suggested by an earlier poster, you can pull your injectors off and get them cleaned in a de-carbonizing solution. The same can be done for your turbo & wastegate.

[Mohnish]

Originally Posted by RedMM340

I wish I could figure out how to the multi quotes to answer questions one by one...

Click on the quote button ... you will be able to figure it out.
There is a start quote command which goes something like quote=RedMM340;899472] then comes the part you want to quote and then the end quote command that goes /quote]. I intentionally skipped the [ at the start of the command in both cases else it would become a quote. May be, one of the moderators on team-bhp who checks my posts can help on this?

Originally Posted by RedMM340

I have the same motor in my Jeep...

Curious, did you do an engine swap?

Originally Posted by RedMM340

The surge in power is normal for a turbo engine, and sure feels good.

Yeah it sure does !

Originally Posted by RedMM340

You can have slight amounts of air...Don't do it unless you feel confident doing it.

Have done it a number of times before...been using diesels since over 20 years now...Have had air locks in the 'old' diesels so so many times!!! Will do and whill also clean out the nozzles.

Originally Posted by RedMM340

Valve clearances are pretty simple...But honestly, I really doubt that this will solve your problem.

Yep, I too am not inclined to believe this is the problem, primarily cause the vibration is far too mild. Besides, would like to go after the more simpler remidies (lazy)

Originally Posted by RedMM340

As suggested by an earlier poster, you can pull your injectors off and get them cleaned in a de-carbonizing solution. The same can be done for your turbo & wastegate.

Injector cleaning will do,but have'nt yet opened or seen open a turbo & wastegate, so would'nt like to figet with that and also am not confident with the local mechanics with this part...more so cause I myself don't have hands on expreience with this unit ( though I understand how it works )

Thanks RedMM340 for your input...Will post later this eveing on whats done today and results if any...!