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+--- Thread: knocking noise, is it the injection pump? (/showthread.php?tid=6681)
knocking noise, is it the injection pump? - Whizbang - 08-13-2015
So I've been chasing this loud knocking noise for some time. Began with only after freeway driving, but became persistent over a few months. I thought it was lifters, and a few did test bad when I pulled them out. Replaced them all. Noise didnt change at all.
I also cracked each injector to make sure there was no air. The noise did not stop regardless of each injector being cracked open.
So i used the long broom handle to the ear trick as a stethoscope because im hooky. Was reasonably quiet until i touched the body of the pump. Thump thump thump... focused from the center of the pump.... It seemed to correspond with my ticking noise.
The pump is leaking externally but not sure how related that point is. Sooo... pump going out? The remaining options seem to be vacuum pump?
RE: knocking noise, is it the injection pump? - Torkey - 08-13-2015
Does it change with the engine RPM and did you listen to the injectors? Might be injector nailing.
RE: knocking noise, is it the injection pump? - Whizbang - 08-13-2015
Knocks increase with engine speed. Injectors didnt seem to be loud, nor did the noise stop when i cracked them
RE: knocking noise, is it the injection pump? - Torkey - 08-13-2015
What engine do you have?
RE: knocking noise, is it the injection pump? - Whizbang - 08-13-2015
Om603
RE: knocking noise, is it the injection pump? - Torkey - 08-13-2015
The injection pumps don't fail that often. It might be the mechanical fuel lift pump that is attached to the IP near the center. Those are more likely to fail and much less expensive to repair.
I would investigate that before replacing the pump.
RE: knocking noise, is it the injection pump? - Whizbang - 08-13-2015
running out of options at this point. I think I have another lift pump laying around. I do have another IP on the shelf too.
RE: knocking noise, is it the injection pump? - Torkey - 08-13-2015
Let us know how it works out for you.
RE: knocking noise, is it the injection pump? - barrote - 08-14-2015
well, try to detach each injector with engine running, if u hear any change in the five cylinder firing, it might be something in the injector.
high nailing noise (overall) can be from too much advance. as if u have damage at the pre cups tip , the MB smothness disapears and start to ratle.
the main engine belt stretcher, in many cases makes a lot of noise when the damper is bad shape, but usually is not the damper but instead the big bolt bearing. wich wears out and ratles and knocks , disgusting noise.
well all this , and then u have piston to Wall knock, rings broken, delivery valves at IP. such a bunch of things that knock.....
start by retarding the injection a bit. it takes u 5 min. and then go by the injector unplug.... maybe u sort it out.
post a vídeo. it helps a lot.
RE: knocking noise, is it the injection pump? - Whizbang - 08-14-2015
Ill give those a try! I already did the injectors and had no change.
RE: knocking noise, is it the injection pump? - erx - 08-14-2015
First check the vacuum pump, i've seen many of them being broken and they also make knocking noise.
RE: knocking noise, is it the injection pump? - Whizbang - 08-14-2015
Here is a video http://s1089.photobucket.com/user/WhizbangRally/media/20150729_111003_zpszgbyyoz7.mp4.html
RE: knocking noise, is it the injection pump? - Whizbang - 08-14-2015
I bought a real stethoscope. Vacuum pump is actually the quietest thing i found. Injectors seem pretty loud. Each is as loud as the other. But when i disconnect thr injectors the noise doesnt chnage.
RE: knocking noise, is it the injection pump? - erx - 08-14-2015
It seems like belt tensioner bushes are rattling, it's fast knocking not one knock per stroke.
RE: knocking noise, is it the injection pump? - Whizbang - 08-14-2015
i wish I had a better microphone. I have a fast knock the mic seems to pick up on better, but there is a knock per stroke that is much louder and my is main concern. You can hear it bouncing off houses and fences when you drive. A deeper muffle knock at the same time can be heard through the air filter. I assume its related.
RE: knocking noise, is it the injection pump? - Torkey - 08-14-2015
It doesn't sound like piston slap to me. What about the transmission? maybe the sound is telegraphing into the engine bay? Long shot, I know.
RE: knocking noise, is it the injection pump? - 50harleyrider - 08-15-2015
How hard is it to R&R lifters in an OM606.962?
RE: knocking noise, is it the injection pump? - barrote - 08-16-2015
i would try to run the engine without the belt, it does seem to be the bloody hinge beating. is a bit loud but it seems the tensioner hinge.
another noise is the clutch , that car has a clutch? if so push it in and out close to a Wall. report back.
regards
RE: knocking noise, is it the injection pump? - Whizbang - 08-17-2015
Regarding the belt tensioner. Would only the damper make the noise or the whole tensioner body?
RE: knocking noise, is it the injection pump? - Whizbang - 08-17-2015
the other thing is, the noise that i am concerned with i can hear echoing out of the intake
RE: knocking noise, is it the injection pump? - anjay - 08-18-2015
Since you hear it coming from intake most likely is collapsed valve lifter. Sometimes after running for a while it will eventually go away. When I had same problem at first I changed three what I thought were noisy. After taking of camshaft third time I changed them all. After all they have same milage.
RE: knocking noise, is it the injection pump? - Whizbang - 08-18-2015
But all my lifters are new.
RE: knocking noise, is it the injection pump? - barrote - 08-18-2015
(08-17-2015, 09:08 PM)Whizbang Regarding the belt tensioner. Would only the damper make the noise or the whole tensioner body?
what makes the noise is the hinge. very litle to do with the damper, but if the damper is in bad shape both toguether make a awfull noise like that.
what about the trans, do u have a clutch ? or is auto?
RE: knocking noise, is it the injection pump? - barrote - 08-18-2015
For those with special ideas, in a MB engine u only replace what is damaged, it was built like that, even most of the gaskets can be reused.
the failure u can find in a MB hyd tappet is crown broken, that is visible from outside, all that fancy theories dont aplly to MB hyd tappets, although the use of mineral oil and diesel with high concentrations of sulphur, wich is the case in USA, may lead to defalt hyd tappets. remove them clean them , flush the engine oil system, fill with sinthetic/semi oil or 15W40 for turbodiesels. and u should be fine with it.
well, even with abuse a 603 engine can last for 1500K miles without breaking, of course with preventive maintnance of course.
regards
RE: knocking noise, is it the injection pump? - Whizbang - 08-18-2015
Its an automatic. I replaced the hydraulic lifters with new INA last week.
RE: knocking noise, is it the injection pump? - Whizbang - 08-18-2015
ordered new tensioner assembly and damper today. Will likely arrive tomorrow and I'll put it on and report back.
RE: knocking noise, is it the injection pump? - barrote - 08-18-2015
u people and the lifters , that thing is called HYDRAULIC AUTOMATIC ADJUSTABLE TAPPETS, they dont fail. every now and then they need cleaning and that is related to oil and fuel , not to any malfunction.
u´ll see that engine becomes so quiet as baby.
did u change the pump position like advance ? or did u mess up with the advance mechanism? it seems stupid but the advance mechanism can play some tricks on us.
RE: knocking noise, is it the injection pump? - Whizbang - 08-18-2015
i haven't touched the advancement on the pump, nor has the pump been off since I've had the car. The noise never existed when I got the car. When I went to the HX30, the noise would occur only after driving on the freeway, but not around town. now its permanent.
RE: knocking noise, is it the injection pump? - Whizbang - 08-18-2015
http://youtu.be/hR4RIwQFEVs
RE: knocking noise, is it the injection pump? - barrote - 08-19-2015
yep i see.... u should heard mine ...... https://www.youtube.com/watch?v=UkxQ-OOULH8
the only strange noise i can hear from the vídeo is , the intake wich is much louder, the exaust u can hear the firing . and the belt stetcher... but thats me.
MB engines like to setle, dont worry they are not ford´s
RE: knocking noise, is it the injection pump? - Whizbang - 08-19-2015
Took the manifold off today and replaced the glow plugs finally. Values are all built up. seems like ill need every single stem seal in the future. they are quite cruddy. would the CRC intake valve cleaner help with that some in the meantime?
I also replace the belt, tensioner, and damper.
RE: knocking noise, is it the injection pump? - barrote - 08-20-2015
so how was it? noise disapear? i´m curious about that noise!!!! did u herd my engine
thats a loud thing...if u manage to remove the glow plugs (complete) u´re a lucky fella. ther´s a withe paste wich is recomended for that brand Bardhall , u should have it there.
RE: knocking noise, is it the injection pump? - Whizbang - 08-20-2015
The noise is actually worse now
RE: knocking noise, is it the injection pump? - barrote - 08-21-2015
so its related , try to drive the engine without the belt , it can be from the stretching mechanism. that big bolt thats what make the ressonance. usually with time it setles . but u had a new device right , or u just changed the damper?
RE: knocking noise, is it the injection pump? - Whizbang - 08-21-2015
I changed the damper and tensioner. I did the manifold gasket too. Valves were rather cruddy
RE: knocking noise, is it the injection pump? - barrote - 08-21-2015
well it may be placebo efect....
in the vídeo u posted i couldn´t hear any out or regular noise... compared to mine... give it some time if anything is really bad it will show soon soon.
regards
RE: knocking noise, is it the injection pump? - Whizbang - 08-21-2015
i cracked the #2 injector today and the noise actually stopped. So ill look at doing a leak down on it and/or check the injector.
RE: knocking noise, is it the injection pump? - barrote - 08-22-2015
that´s something . take it out clean it and repop it . it can be a stuck injector. or something else further down....
good luck.