Rod knock? and other bad things

[Old Blue]

Well, I just got back home and into my little truck project in my sig for the past 3 days. I started her up after getting the turbo kit on and lo and behold I've got what sounds to be a nasty bottom end knock. This truck was supposed to be at the rally, but I had 2 weeks vacation in Oklahoma, followed by a kidney stone the day after I returned home, as soon as I got over that my grandfather fell and broke his hip so I spent two weeks staying with them helping out with that.

I've done a lot to the truck all at once, it hasn't run since I did new glow plugs, new fuel tanks, new Moose IP, new BB code injectors, new Fort Wayne clutch, new electric lift pump, and of course the Banks Sidewinder I was just finishing up and finally able to start it.

I figure it could be two things. One, I got dirt in a new injector and its hanging open or sticking. I did what I could tonight before I got tired of it and felt for hot lines (none were hot) and loosened 7 of the 8 injector lines to see if I could isolate the cylinder with no luck so far. The rear passenger side line was giving me trouble so I quit for the evening.

The second possibility is hydrolock. When I first kicked the motor over before I had the turbo fully installed some water fell off the engine or so I thought - it could have come out of one of the open headers. I was starting the truck to clean out the oil line that feeds the turbo and to prime up the new electric pump and IP combo. I only let the engine run for a few seconds while I pumped a quart of oil out of the turbo oil line. I didn't hear the knock at that time, but on top of the engine it is a lot harder to hear it, plus the exhaust was not on either so the truck was louder in general.

There was a few days where the engine set without glow plugs in it before I went on vacation, it is possible water ran down into a cylinder or into the open intake somehow - the truck is outside with the hood closed, but anything is possible. I plan to do a compression test on all 8 again tomorrow and see where I stand. Any other suggestions are welcome, I'm just less than thrilled at this point.

 

[paulw]

wow sounds like a lot of stuff you did at one time is the noise there when you rev the truck up or just at idle could just be an exhaust leak.and by the way im only 30 min south from you.

 

[OLDBULL8]

If you had the air filter off all that time before installing the turbo, we've had an awful lot of rain. Not good with the GP's out. Could have water in the intake manifold. Not good. Those hood seals leak.

 

[Exekiel69]

Yep, the hood seals do leak and drip from right above the intake. Since You just installed new ip and injectors I would make sure to rule them out before tearing into it.

 

[Old Blue]

Well I just got done with the compression test on a warm engine (not hot). All cylinders were between 350 and 375, which compares favorably to the cold numbers I did before installing the new items. I'm not sure how drastically a hydrolock situation would alter the compression, but I was expecting something to show up on compression if that was the problem. I've got videos uploading so you can listen to the knock, it is definitely much more noticeable under the truck and less so on top of the engine. All I know is it sounds horrible...

I had the intake covered with a plastic bag and rubber band most of the time, and I don't think it rained while I had the plugs out, but that's been months ago so I could be mistaken, I don't want to rule anything out prematurely. All it would take is leaving the bag off one time over the course of the 3 or 4 months the truck has been down.

The noise follows the RPMs up under no load and is worse at certain RPMs. I have two videos, one walking around at idle, and the other in the truck with a slow rev to 2500 rpm. As I rev the truck up, there is a very slight shudder at specific speeds. No noticeable excess white or grey smoke, although this Moose pump sure can make some black smoke if you give it a little pedal.

 

[Old Blue]

Here are the videos of the knock. This one is a walk around at idle.
http://youtu.be/8meyJmJcVXw

 

[Old Blue]

Here is the second one - through the rev range up to 2500:

http://youtu.be/ijtG_xGTwXI

 

[Exekiel69]

To Me it sounds like it is coming from behind the engine, maybe fw or fork or to bearing?

 

[Old Blue]

I was thinking of picking up one of those new inspection cameras at Harbor Freight, they are 640 x 480 resolution and can take digital pictures, it has some decent reviews. I was wondering if it would be useful up the oil drain or down injector or glow plug bores. It might not fit in a glow plug bore, it says 8.5mm head in the specifications. 38" reach on the cable.

I think it sounds louder behind the engine as well, and I can really hear and feel the knock if I stick a large pry bar on the rear of the engine block or transmission case - but I don't have much experience here with noise diagnostics... I did manage to loosen cylinder 7's line this morning before taking the GPs out, it might have changed the knock slightly but it was still present.

 

[freebird01]

have you checked to make sure its full of oil? lol

on a more serious note.... try cracking the injecter lines at each injector one at a time and see if it goes away...

 

[Old Blue]

Yeah, I did make sure it had oil before I started it. ;p

I just barred it over by hand since I have the plugs out, feels like I might have a tight spot that lasts for between 90 and 180 degrees of rotation, I need to try it again and see if it's every 360 or 720 degrees and make sure it's not my imagination. There was no discernible free play when changing directions for a few degrees, so there must still be bearings in there.

 

[OLDBULL8]

The glow plug holes are 10MM. Wouldn't do any good looking in the injector or glow plug holes, all you would see is the precombustion chamber. I would say a camera is almost useless on a diesel engine.

 

[Old Blue]

My grandad has a nice shop to work in and an engine crane, since I've found the tight spot, this engine is coming out. I'll keep you all posted.

 

[riotwarrior]

Does engaging or disengaging clutch make any difference? I see the truck is in 4Low how about both trans and tcase in neutral? What happens if you wiggle the clutch release fork when running or hold onto it do you feel a knock does it change? sounds like something outside the engine to me...does not sounds like a bottom end knock..but not familiar with one on this engine...

 

[firehawk]

Check your clutch. Remove the bottom cover then start. If it is rubbing the cover, it will make a similar sound. Check the simple stuff first before pulling the motor.