Knock, I need help guys, I'm in trouble.
09-10-2005, 01:08 AM
#16
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Thread Starter
Originally Posted by 12valve@heart
Too bad there isn't a companion cylinder firing at the same time so that you could swap injector lines to see if the problem moves with the line or stays with the cylinder. I can't see that a compression test would do you any good. The only possible test that I can think of would be to run a dial indicator thru the injector hole and see if you can detect any difference in the travel per degree of crank movement of #3 versus another cylinder. If there is a difference, it could indicate a wristpin or rod bearing but it won't tell you if the problem is the pump. You've got me stumped Haulin. I'm assuming that there's no way to drop the pan w/o raising the motor significantly, right? Otherwise you'd have already dropped it and plastigaged #3.
Keep us posted and we'll keep brainstorming.
Keep us posted and we'll keep brainstorming.
I have spent hours on the internet trying to get information on the pump possibilities and the function of the delivery valves. Looks like a spring loaded, glorified check valve that keeps pressure out of the lines and the lines full for injection. Looks like if one is bad, it would misfire, causing what I have. Afraid to pull one, don't want to scrap a good vp.
Oh well, it looks like the pan comes off, and if it is bad the engine comes out. Supposed to get more than 100k out of the Cummins built engine. I did not build this one, Cummins did.
thanks for the concern....
09-10-2005, 07:09 PM
#17
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Is there any way you could borrow a VP44 and install it to prove if it is the pump or not? Hopefully, a supplier after hearing your symtoms and trouble shooting would meet you half way on this. After all, if it is the pump, you would be buying it anyway.
Replacing the pump is a lot easier then pulling the pan to check on a rod bearing or piston.
Replacing the pump is a lot easier then pulling the pan to check on a rod bearing or piston.
09-10-2005, 07:20 PM
#19
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Originally Posted by Marine
Could it be a wrist pin?
Mike
Mike
I had a knock on a 500 Mack, but it came all at once. It ended up being a broken connecting rod.
Mike
09-10-2005, 09:49 PM
#21
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Thread Starter
Originally Posted by kerryneb
Haulin,
Just a thought... are you able to swap delivery valve from #3 to another location? also try swapping injectors.
Just a thought... are you able to swap delivery valve from #3 to another location? also try swapping injectors.
Marine at this point, the pan has to come down to see anything. I seriously doubt the wrist pin because they are so oversized and once the knock started it increased too fast for a wrist pin. A pin would run on for quite a while, just getting looser.
Also with the air compressor and big truck power steering pump installation, pulling the VP is not an easy job either. I have not been able to find where the pump could cause it.
I also found in the Service Manual under noises... "power knock, pull pan for bearing check" so I guess that about sums it up. It can't believe that it took out a bearing in 100k.
09-10-2005, 10:22 PM
#23
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Originally Posted by fschiola
Could an oil analysis show you if a bearing is coppering?
09-11-2005, 02:55 AM
#26
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Originally Posted by torquefan
I heard a noise just like you describe on a 6.5 not too long ago, would fade in and out at idle, turned out to be a wrist pin, and it was quite obvious once the oil pan was off. You could poke the piston up about .030" in the bore with a small prybar. I know I've never seen one fail on a Cummins, but it's what I thought of when you described it. Anyway I hope you find it soon and it's as painless as possible. Good luck HID, we're thinkin about you. 
09-11-2005, 09:04 AM
#27
Registered User
Torquefan beat me to it. Very likely a wrist pin bushing, pin boss, or a cracked/broken pin. The movement of the piston "stops" at tdc and bdc for just a little bit, so it's easy to detect when turning the motor slowly and watching the piston top.
09-11-2005, 11:11 PM
#28
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Originally Posted by Haulin_in_Dixie
Yes but that would take another week of lost work before I could start on it. I lost 2200 this week to lost loads. So tomorrow it comes apart. No choice.
Keep us posted.
09-12-2005, 02:26 PM
#29
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Thread Starter
Cummins response to the above information.....
I thought that this might be of interest. I contacted Cummins about the knock including the info from this thread. I was looking for a possible VP cause...
Bill, we are not in any position to troubleshoot engine knocks by email. If there was a bearing or bushing failure, you would have metal debris in the filter. Since you have checked out the cylinder head, that would be eliminated. So, it could be a piston pin or possibly a tappet knock. We have not heard of VP44 pumps that knock. Sounds like you need to drop the oil pan and take a look at everything on the bottom end, then go from there. It is no likely to go away so you will need to find it and make repairs before something comes apart and causes a lot of damage.
Bill, we are not in any position to troubleshoot engine knocks by email. If there was a bearing or bushing failure, you would have metal debris in the filter. Since you have checked out the cylinder head, that would be eliminated. So, it could be a piston pin or possibly a tappet knock. We have not heard of VP44 pumps that knock. Sounds like you need to drop the oil pan and take a look at everything on the bottom end, then go from there. It is no likely to go away so you will need to find it and make repairs before something comes apart and causes a lot of damage.
09-12-2005, 03:30 PM
#30
Originally Posted by Haulin_in_Dixie
I thought that this might be of interest. I contacted Cummins about the knock including the info from this thread. I was looking for a possible VP cause...
Bill, we are not in any position to troubleshoot engine knocks by email. If there was a bearing or bushing failure, you would have metal debris in the filter. Since you have checked out the cylinder head, that would be eliminated. So, it could be a piston pin or possibly a tappet knock. We have not heard of VP44 pumps that knock. Sounds like you need to drop the oil pan and take a look at everything on the bottom end, then go from there. It is no likely to go away so you will need to find it and make repairs before something comes apart and causes a lot of damage.
Bill, we are not in any position to troubleshoot engine knocks by email. If there was a bearing or bushing failure, you would have metal debris in the filter. Since you have checked out the cylinder head, that would be eliminated. So, it could be a piston pin or possibly a tappet knock. We have not heard of VP44 pumps that knock. Sounds like you need to drop the oil pan and take a look at everything on the bottom end, then go from there. It is no likely to go away so you will need to find it and make repairs before something comes apart and causes a lot of damage.
Hope it turns out to be better than it sounds.
Good Luck.