Just to completely eliminate the balance shaft assembly, on your next oil change use a scope and inspect the oil pan and balance shaft assembly through the oil pan drain hole. Look to see if your balance shaft bushings are moving or have fallen out. It will cost you the price of an oil change and having the vehicle up on a hoist. Almost any shop with a scope can easily do this for you. Also don't rule out a warped torque converter or loose/broken bolts securing you bell housing to the engine or trans. I've seen this an awlful lot after transmission work being done without techs using new bolts and or torqueing the bolts properly.

This engine is a four cylinder four stroke diesel. The counter balance shafts and oil pump are in the balance shaft assembly between the oil pan and the engine block directly under the crankshaft. The crankshaft and counter balance shaft are connected directly by hard gears and I "think" are a 4 to 1 ratio. If you are having engine vibrations this is where you want to look. I have seen the key holding a gear shear and or deform which will throw the balance off causing engine vibrations. I have seen the bushings ware and fall out causing vibrations and loss in oil pressure. (Not always due to fuel delutions). Reading all which you have posted I would follow this path and eliminate these posibilties. The large detroit cousins of this engine are also 4 cylinders. Your vibration analysis should closely match the bigger engines. They run in the same rpm range but use DDEC controlled injection systems.

Thanks for all your suggestions, this is greatly appreciated.
OK, give me some time to try these out one by one and I'll come back to you

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05 CRD Renegade

Very interesting data I must say. I would dearly have liked to have two or more points where data was captured. E.g. at 1300 and 2000 rpm as well as idle. I know it isn't easy manually adjusting the RPM, but if you can use a brick or something to hold the pedal it doesn't matter if it is 1958rpm or 2000 rpm, just keep the RPM constant while measuring.

I know a little bit about accelerometers because I used to work at Grundfos with accelerometers for detecting bearing failures in induction motors. Is it possible I can get a track of the vibration signal? Any data file will do fine.

Normally when measuring vibration and it comes from an internal part (say a bearing for instance) the resulting vibration signal is completely different. You cannot directly find where the source is, when you look at a vibration signals FFT. You need to do some pre-processing.

The reason is that the internal vibrated component is stuck in the major engine structure, and the component can only talk to us through the entire engine. That means when the little component says "beep" the engine transfers the beep through its structure, changes the frequency and amplitude, and outputs a vibration signal. The pre-processing technique is highly likely known by your colleagues as Envelope analysis, can you tell me if they did such analysis?

If not, tell them to use an envelope analyser on the signal, and report back what frequency they come up with then. It is very likely that the real frequency isn't more than 2x or 4x the crankspeed, but because of the engine structure and vibration resonance the frequency is changed to a much higher one.

At least this theory is true for bearing analysis in induction motors, small or big.

How was the transmission set up?

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L.O.S.T forever!
Silver 2002 Skoda Fabia TDI, 235,000km
Former car: Jeep KJ 2003 CRD

DIESEL - saving millions of liters of petrol every day!

Uffe,
I only have the report in a word document with some screen shots of the data if that is of any help. The transmission was in drive when the measurements were taken.
PM me with an email address and I can send you the doc if you like. Unfortunately I don't work on that site anymore so I can't get the measurements taken again.

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05 CRD Renegade

I'm sorry but without the raw data it is nearly impossible to do a proper analysis, perhaps it can be done if someone took the time to manually go through all the sample points in the data and re-wrote them in a vector which I can analyse. This should take a normal hard working person about 5 months to complete. I don't recommend it

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L.O.S.T forever!
Silver 2002 Skoda Fabia TDI, 235,000km
Former car: Jeep KJ 2003 CRD

DIESEL - saving millions of liters of petrol every day!

Some have reported the over run clutch on the alternator can give a vibration. You could pull the serpintene belt to try it

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Atlantic Blue 06 CRD Limited (his)
Joined by a 2000 XJ Classic (hers)

Since the symptom doesn't occur in NEUTRAL, only in DRIVE or REVERSE, I'd suspect torque twist forcing something, such as ATF filler tube, against the body - also, that chinese finger-torture device in the down-pipe B4 the soot-trap is placed therein in order to prevent just such vibration into the body thru the exhaust system hangers, as well as allow excess movement without stressing the turbine housing - which hangers, by the way, can be inverted during mis-service, forcing the exhaust pipe into non-spec'ed position - the isolator and tailpipe section is spec'ed to hang suspended, not perch

DRIVE\REVERSE also has the effect of reducing crank rpm below that in NEUTRAL, allowing the alt pulley and serp belt to set up additional vibration - check those and the idlers by removing the serp belt, allow the engine to idle in R-N-D for a comparo

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'05 CRD Limited
Pricol EGT, Boost
GDE Hot '11; EDGE Trail switched
SEGR; Provent; Magnaflow;
Suncoast T\C, Transgo Tow'n'Go switch;
Cummins LP module, Fleetguard filter, Filterminder
2.5" Daystar f, OME r; Ranchos; K80767's, Al's lifted uppers
Rubicons, 2.55 Goodyears
Four in a row really makes it go

A very interesting thread since I'm having the same problem.

http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=43536


I will look to see if any hoses or metal lines are not routed correctly. I wish I had another CRD kicking around to compare too.

Thanks gmctd & Joe for the advise on the alt pulley. Already tried that and there was no change.
Some good news though... I found the cause of the drumming sound (as best as I can describe it) in the cabin. I decided to change the coolant and whilst the coolant tank was empty I removed it to get a better look at the firewall and behind the engine. I found that the lower bolt on the metal bracket that supports the bottom of the coolant tank was loose.
The bad news is that the roughness or harshness that has developed over the last year or so at idle and under acceleration is still there. Note that the vibration is noticeably worse in FT 4WD. Won a battle but not the war.
I was able to check clearances of some pretty contorted pipework that runs along the firewall and also the transmission filler tube. All are clear of contact (although pretty tight in places) and firm.
I have limited movement in my upper shoulders at the moment so when that is better I will squeeze under the vehicle and start on the exhaust and drivetrain again.

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05 CRD Renegade

Hi MackJ

I know it has been a while but I have a very similar problem currently on my Jeep CRD . Did you manage to solve your Jeep`s vibration problem ?