have an 86 sdl with a knock.just number 3 cyl.cracked inj lines and number 3 is the culprit.knocks pretty good up to about 1200 rpm then it's gone,i switched injectors with 2 other cyls and it's still #3.i also have a very minor rough idle.does this sound like delivery valve seals or do i need to dig deeper.one thing i noticed is if you feel the inj lines the #3 line has a distinct pulse to it where the others you can just feel a little tap.

Does sound like a delivery valve or IP problem. If the delivery valve isn't leaking externally try a couple of cans of Diesel Purge first. Run it directly through the IP using the instructions in the archives or at www.************************

Sixto
... stay tuned

i have no external leakage.i got the socket and seals from phil.i might try to put em in tomorrow or sunday if i get a chance.i talked to my diesel shop and they can't time this thing,said take it to mercedes,so looks like i might end up there,just wish they weren't 3 hours away.

Checking IP timing is easy with the right tool. Post a thread asking to rent the 603 IP timing A-B light device.

Sixto

well i went out and changed the delivery valve seal and o-ring on #3 and it sounds a little quietter but still hammers.what does this a-b light entail.i used to have an inductive pickup timing box i used on my olds 5.7's,had a funny little pickup that clamped on the number 1 inj line.seemed to work about half the time.

Very very likely you have a bad delivery seal on #3 OR low compression on that cylinder.

How did you torque the seal? If you don't follow the proper procedure, it won't seal (torque twice to 25 ft/lbs, unscrewing each time, then once to 30 ft/lbs.

If that doesn't work, do a compression check -- also check the valve tappet as the clack pretty badly when bad -- you should not be able to collapse it with a screwdriver.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

What about a bad pre chamber in cylinder 3? I'd compression test it and see what you get. Maybe take a look at the pre chamber while the injector is out.

Another option would be to remove the IP and have it bench tested, it still could be an IP problem.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

fred funny you should mention lifters.one thing i have been thinking about.the seals on the oil filter shaft.don't these seals seal the area for oil flow to the lifters.last oil change they were hard as a rock.i got some from phil,just need to pull the lid and replace em.

FYI....All the 603's I've had in with this kind of 'knock' have all been on #3 or #5 cylinders....and one, on both !

Siezed rings and scored bores....piston skirt damage....liner and pistons job.
Sorry to be a bringer of bad tidings ..

For some reason, these motors seem to eat #3 in the majority of cases.....others may disagree.

If knock goes away on decel', this is most likely the problem.

BTW...What's this new addition to posts EDIT...'Multi Quote', or summat ?



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"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

Any idea as to cause??

Why #3 and #5??

well above about 1200 rpm's it quiets down and even on decel,i really don't notice it knocking til it hits about that 1100-1200 range.

I'm not 100% sure Brian.....Seems the greatest area of distortion on that motor. Perhaps the engine mount loadings.....
May also be that these two cylinder see primary filling and are first to suffer from the crud build up in the manifold which on occasions breaks loose.

These motors come in all the time...well, a lot, with restricted intake manifolds. The EGR valve seems to be the culprit here though.
Recently had one engine in that suffered both 3 and 5 cylinders scored up with no history of overheating or poor servicing.

I guess we should take a survey and see who else has experienced the same problem.

In fact...I'll do that right now.


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__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

The A-B light device is a sensor that shows the position of the IP timing lug relative to the reference position. It lights A when the lug is above the sensor and B when the lug is below the sensor. For a few minutes in the angle measurement sense both A and B light indicating that the lug is right on the sensor. So what you do is set the crank to 14* ATDC or whatever reference crank position you want, attach the A-B light device to the IP, then advance or retard the IP until both A and B are lit.

Sixto
... stay tuned

my jetta intake was plugged up pretty good when i got it,and it's a typical problem with them.also my old oldsmobile 5.7's had a problem,but my 6.2 and 6.5 chevy's i get an oil film in the intake but nothing major,and my 6.5 has 477,000 miles.is this something that a guy might want to consider a ccv filter to slow down the crud build-up??now ya got me curious i might have go pull the intake today just to see whats in there.i personally don't think its a scored piston by the sound of it.it sounds more like what i have heard refered to as nailing,more of a tapping type knock rather then a deep knock.

dkveuro,as i mentioned in my first post the number 3 line has a very distinct pulse to it where as the others are like a little tap on the line,could there be a fueling problem in the pump on number 3 that is putting too much fuel to 3 thus causing say excess soot buildup in 3 thus maybe contributing to the scoring,stuck rings etc that you are seeing.also idling, this thing smells like rich diesel exhaust almost to the point of burning your eyes.looking at the intake setup i fine it odd that just 3 and 5 seem to be affected,i would think number 2 as it's right under the crossover pipe.