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  #1  
Old 10-12-2008, 09:32 PM
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Newbie Knocking Question

New to Mercedes Diesels and have been looking and listening at the threads on knocking. Could anyone tell me if I have a knocking problem, I know that there is considerable fidelity loss in using utube however the video is very close to how the engine sounds.
Video
http://www.youtube.com/watch?v=HLGMPZh9GS0
1983 300sd
compression
1 =280
2=300
3=300
4=320
5=280
Oil pressure looks good just under 3 at idle.
On a gas vehicle I would suspect a rod bearing however the oil pressure is to high (not sure for diesel)
Also did the valves and diesel purge
Thanks

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  #2  
Old 10-12-2008, 10:03 PM
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sounds ok to me, If the oil pressure is holding then I wouldn't suspect a bad rod bearing. Have you tried to further investigate the sound? Have you adjusted the valves or checked for injector nailing?
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  #3  
Old 10-13-2008, 01:14 AM
'da 'browski-'owski
 
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Sounds like mine does. I have suspicion that one injector is nailing, I changed all five nozzles to monarchs and one leaked after the install, no matter how many times I dissected, cleaned, reassembled, and retorqued. I was moving from Portland to phoenix at the time and couldn't afford to leak fuel on the drive, so as any sane benzer might, I pulled an injector from a junkyard and popped it in mine. say... I need to get that sucker situated...

I wouldnt be too paranoid about the noise.

but be sure to check that loose nut behind the wheel
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Last edited by hoborobot69; 10-13-2008 at 01:17 AM. Reason: edit
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  #4  
Old 10-13-2008, 01:17 AM
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You sure about those compression numbers? Aren't those rather low? From the video it sounds kinda like worn injectors.

-Jason
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  #5  
Old 10-13-2008, 01:22 AM
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sounds normal, take the car to a shop and have them install new injector nozzles. It shouldnt be any more than 120$ tops and it should purr.
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  #6  
Old 10-13-2008, 10:23 PM
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Thanks I think Ill replace my injector nozzles when i get a spare $150. dont think ill have a shop do it though.
Any advice on what brand? It looks like there is a post where the guy really likes the Bosio nozzles.

Also I misstated in my original post the oil pressure. After driving around in traffic today and on the freeway it looks like my oil pressure is just under 2 not 3 at idle. Hope this is not indicative of a failing rod bearing.
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  #7  
Old 10-13-2008, 11:28 PM
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1.5 bar at idle (and at operating temperature) is perfectly normal, no reason to be concerned about that.
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  #8  
Old 10-14-2008, 01:12 AM
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Quote:
Originally Posted by AdrianMiura View Post
Thanks I think Ill replace my injector nozzles when i get a spare $150. dont think ill have a shop do it though.
Any advice on what brand? It looks like there is a post where the guy really likes the Bosio nozzles.

Also I misstated in my original post the oil pressure. After driving around in traffic today and on the freeway it looks like my oil pressure is just under 2 not 3 at idle. Hope this is not indicative of a failing rod bearing.
alot of people are happy with Bosi nozzles. if you want bosch make sure they are made in GERMANY not the knockoffs made in india because they are total crap.
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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.
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  #9  
Old 10-14-2008, 01:13 AM
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Where do you guys get your nozzles from?
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  #10  
Old 10-14-2008, 09:26 AM
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Quote:
Originally Posted by johnathan1 View Post
Where do you guys get your nozzles from?
I got a set of Monarchs from C Sean Watts in North Carolina. Brand new, no junk. Runs really well, reduced smoke and improved mpg. I actually thought my fuel guage was stuck for the first 100 miles or so! Sean is a member of this forum.
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  #11  
Old 10-14-2008, 12:25 PM
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Quote:
Originally Posted by GRIESL View Post
I got a set of Monarchs from C Sean Watts in North Carolina. Brand new, no junk. Runs really well, reduced smoke and improved mpg. I actually thought my fuel guage was stuck for the first 100 miles or so! Sean is a member of this forum.
+1 on Mr. Watts
I replaced my 603 nozzles with a set from Sean about 2 weeks ago. No issues, car runs well.
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  #12  
Old 10-14-2008, 02:28 PM
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How much for a whole set? (If you don't mind me asking...)
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  #13  
Old 10-16-2008, 02:42 PM
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Quote:
Originally Posted by johnathan1 View Post
How much for a whole set? (If you don't mind me asking...)
253 plus 50 core if you don't send in your old ones, plus 10.50 for shipping. Worth every penny.

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