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-   -   What is this knock... (http://www.peachparts.com/shopforum/diesel-discussion/228214-what-knock.html)

DslBnz 07-20-2008 10:50 PM

What is this knock...
 
Mysterious knock...prompted me to...
Replace all lifters (5 were gone), determine it was not vacuum pump...Noise seems to come from intake runner #2. Other than this, the car runs great! This noise came in and out over a period of two weeks. And now it's terrible. So, what could it be? Cranking the injector lines off on each cylinder makes no difference at all.

Guys, I've checked the timing; it's perfect...There is no excessive blowby...The engine has very strong compression....It just has a terrible knocking noise that is consistent at all rpms.

I will rev the engine in future video clips. So, if it isn't fuel related, it isn't the pump, it isn't the injectors, what could it be?

http://youtube.com/watch?v=JPFZIiT9bdk

I'm generally an optimist. I don't want to even think it's a bottom-end issue. The car does not burn any oil. It runs super. It definitely sounds like it's coming from up top, but the valve-train is super tight, now.

79Mercy 07-20-2008 10:53 PM

doesn't look there is much oil shooting out.

pawoSD 07-21-2008 12:22 AM

Quote:

Originally Posted by 79Mercy (Post 1915525)
doesn't look there is much oil shooting out.

Thats what I was thinking too....shouldn't the cam lobes be like....bathed in oil?? :eek: Where is all the oil????

79Mercy 07-21-2008 12:26 AM

I started my gasser up without the valve cover on and oil was splashing everywhere

Cervan 07-21-2008 12:27 AM

I think that sound is the sound of the rod hitting the crankshaft and spinning the bearing without any oil...

pawoSD 07-21-2008 12:30 AM

Quote:

Originally Posted by Cervan (Post 1915590)
I think that sound is the sound of the rod hitting the crankshaft and spinning the bearing without any oil...

Exactly what I was thinking.....it does sound very much like a bad rod knock....

JimmyL 07-21-2008 12:40 AM

I agree on the lack of slinging oil. And hold that camera still for a second! :D

compress ignite 07-21-2008 01:11 AM

Oil Pump
 
Little or no Lubrication of Camshaft.
Knocking elsewhere.(Pray it's not a rod)

Weak oil pump...or clogged oil galleries.

I know it's not LOW on oil! (Please God?)

DslBnz 07-21-2008 04:59 PM

Quote:

Originally Posted by compress ignite (Post 1915606)
Little or no Lubrication of Camshaft.
Knocking elsewhere.(Pray it's not a rod)

Weak oil pump...or clogged oil galleries.

I know it's not LOW on oil! (Please God?)

No, it's not low on oil (your prayers are answered). Although it sprays that oil out rapidly with the v-cover removed, I'm careful to always keep it above the min mark on the stick.

Thanks guys. I will follow up when I find out what it is. Here's another clip where I vary the engine revolutions. This digital camera does not provide the best video or sound quality, I guess. Comparing one 603 to another, I also think there should be more oil getting to the top.

http://youtube.com/watch?v=nbcWMyM4p-w

Brian Carlton 07-21-2008 05:09 PM

I agree with the comments related to very low oil to the top end. Something is amiss there.

The knocking speed is at camshaft speed.........about 5.5 knocks per second.......giving you some potential for a low cost repair.

However, I'd disconnect each injector line in sequence while it's running and pray that the knock doesn't disappear when one of the cylinders comes off line.

DslBnz 07-21-2008 05:26 PM

Quote:

Originally Posted by Brian Carlton (Post 1916252)
I agree with the comments related to very low oil to the top end. Something is amiss there.

The knocking speed is at camshaft speed.........about 5.5 knocks per second.......giving you some potential for a low cost repair.

However, I'd disconnect each injector line in sequence while it's running and pray that the knock doesn't disappear when one of the cylinders comes off line.

Brian, I have done this. It doesn't seem to change the value of the knocking, whatsoever. On any cylinder.

Just to prove it, I'll post a video tomorrow of cranking the fuel lines one-by-one.

Thanks again.:)

Brian Carlton 07-21-2008 05:29 PM

Quote:

Originally Posted by DslBnz (Post 1916273)
Brian, I have done this. It doesn't seem to change the value of the knocking, whatsoever. On any cylinder.

Just to prove it, I'll post a video tomorrow of cranking the fuel lines one-by-one.

Thanks again.:)

Good job. That test more than likely rules out the bottom end. No need for further confirmation if you've done it already.

You've got an issue with low oil and some possible damage to the valve train due to the lack of oil. It could be as simple as a completely collapsed lifter...........even if brand new.

Cervan 07-21-2008 09:33 PM

Quote:

Originally Posted by Brian Carlton (Post 1916275)
Good job. That test more than likely rules out the bottom end. No need for further confirmation if you've done it already.

You've got an issue with low oil and some possible damage to the valve train due to the lack of oil. It could be as simple as a completely collapsed lifter...........even if brand new.

Why would this rule out the bottom end?... All he did was check to see if the injector was knocking, not if the rod bearings are coppered? The only other thing i can think it would be is a collapsed lifter, wich would go with the low oil theory as well....

Brian Carlton 07-21-2008 09:40 PM

Quote:

Originally Posted by Cervan (Post 1916482)
Why would this rule out the bottom end?... All he did was check to see if the injector was knocking, not if the rod bearings are coppered? The only other thing i can think it would be is a collapsed lifter, wich would go with the low oil theory as well....

Without the combustion pressures, the noise should be significantly reduced, if not eliminated. The noise exists at 1/2 engine speed...........so, either it's valve train related or combustion related on the bottom end.

I've discounted the possibility of an injector knock..........it appears to be too harsh for that situation.

pawoSD 07-21-2008 10:31 PM

Wow....the 603 is one sweet sounding engine when its revved up! :eek: I never realized it sounded like that. Maybe I will have to consider one someday. :D :D


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