New engine new problems

J

junkyard dog

New member
So I have a real head scratcher right now. Needing some help from those more knowledgeable than myself.

I have a 91 1st gen I've been running a 97 215hp engine in for several years. Engine has been getting more and more tired so I tore down a 96 for a rebuild while still driving the 91. New engine is +.020 mahle power pack piston kit,balanced rotating assembly, Hamilton 178/208 cam,ATI balancer. I reused my injection pump, lift pump,turbos, and installed a new BD SS manifold. Ported the head a little,mostly cleaned everything up. Engine went together with out any real hiccups, fired it up to break in cam, had charge piping disconnected just in case. Upon initial start up I noticed a sound I've never heard from a diesel, it sounded like a gas engine that the timing had jumped on and was pushing air back thru the intake. I shut it down, tried to make heads or tails of it and decided to fire it back up. It is pulling air into the horn good,none coming out as the sound would make you believe. Ended up running it long enough to break the cam in. Retorqued studs and checked valve lash, nothing terribly out of adjustment, done an oil change and fired her back up. The sound increases and decreases with rpm. I have run the truck to operating temp multiple times now. Valve lash is still correct, truck is responsive, pump timing is a little off it seems but I was gonna check/reset that once I could drive it and get everything broke in. I'm at a lose on this one, anyone have any thoughts of wisdom???

Sorry for the novel
 
Take a video or audio file of it, so we can hear it. :)
Chances are it's just the noise of the valves and vacuum being amplified by the intake shelf.

Mark.
 
Mark Nixon said:
Take a video or audio file of it, so we can hear it. :)
Chances are it's just the noise of the valves and vacuum being amplified by the intake shelf.

Mark.
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I'll try to get a video. So what would make it sound different? This is my first diesel rebuild with a cam change. Charge piping is installed now. Sound is slightly less but still there. Forgot to mention I'm running Hamilton springs and retainers also.
 
Drothgeb said:
You could do a leak-down test and see if any of the valves are leaking.
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I thought about this, need to make me up a rig. I kinda expect it to be pretty bad though, I don't feel like iver run it enough to seat the rings yet. The head was completely gonna thru by guy who done all the machine work. I feel confident that its right but I realize even the best make mistakes from time to time also.
 
junkyard dog said:
I'll try to get a video. So what would make it sound different? This is my first diesel rebuild with a cam change. Charge piping is installed now. Sound is slightly less but still there. Forgot to mention I'm running Hamilton springs and retainers also.
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I suppose the cam profile would make it sound different.
Cam timing could be off, or it could be leaking by a valve or rings, it's hard to tell not being there and troubleshooting it.

Mark.
 
Did you measure your piston protrusion and valve depth to verify you had proper PTV clearance? Did you have your block or head surfaced would increase the chances of not having proper PTV unless you had your pistons cut. You could have smacked a valve.
 
kurtimas said:
Did you measure your piston protrusion and valve depth to verify you had proper PTV clearance? Did you have your block or head surfaced would increase the chances of not having proper PTV unless you had your pistons cut. You could have smacked a valve.
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I'll have to look at my notes. I can't remember if I checked it or not. Block was decked as well as head. Took .003-.005 off each. Can't remember exactly #. Running a stock thickness HG also. Engine rolled smoothly on stand after lash was set. I would think any PTV problems would have showed up then.
 
Looking at my notes it appears I either didn't check protrusion or forgot to make a note if I did. I do remember measuring the HG and trying to decide how much it would crush.

Little update: I drove the truck probably 50-60 miles today, no problems other than a small power steering leak. Truck runs good with very little blow by which continued to decrease as the rings seated. Sound still continues. I'm pretty positive it isn't a clearance problem between any components. Is it possible that it has something to do with valve overlap with the cam? Like I said before this is the first Cummins with anything other than a stock cam I've been into.
 
I’ve always been told a cam on a diesel doesn’t change the sound, when I had PDR cam in mine it sounded the same as far as I could tell.
 
junkyard dog said:
Looking at my notes it appears I either didn't check protrusion or forgot to make a note if I did. I do remember measuring the HG and trying to decide how much it would crush.

Little update: I drove the truck probably 50-60 miles today, no problems other than a small power steering leak. Truck runs good with very little blow by which continued to decrease as the rings seated. Sound still continues. I'm pretty positive it isn't a clearance problem between any components. Is it possible that it has something to do with valve overlap with the cam? Like I said before this is the first Cummins with anything other than a stock cam I've been into.
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Wait, you're still hearing the noise, even with the intake all sealed up?

Mark.
 
95cummins5.9 said:
So it must likely has to be valve related.
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I get what your saying,but I can't be heard in exhaust. Which would mean not an exhaust valve any ways maybe intake. I don't think it is PTV clearance cause I would have felt it while rotating engine. I do realize things grow when they get hot and what not.
 
junkyard dog said:
I get what your saying,but I can't be heard in exhaust. Which would mean not an exhaust valve any ways maybe intake. I don't think it is PTV clearance cause I would have felt it while rotating engine. I do realize things grow when they get hot and what not.
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Correct. I'd be checking pushrods.
 
One of your pushrods could have not been seated when you did lash and then “jumped out” or seated all the way giving you a bunch of excess valve lash. I had one jump out once, sounds terrible. Also could have been the friction weld on the ball end of the push rod letting go letting the push rod jump out. I’ve also had that happen before, it also sounds terrible.
 
I remember the first time I pulled the head and went through it with all new parts and thought wow it sounds so different @ start up... turned out to be my paranoia! Is it really loud, or just a tick?
 
I bought an '03 commonrail once that the guy had rebuilt somewhere.
He said "it just makes this noise and I can't figure it out", so he converted to a 12 valve and sold me the engine, which I later sold to somebody as a rebuilder, who found and fixed the problem.
Turns out it had been decked and milled and they put a stock head gasket in it.
The pistons had ever so light imprints in them from just barely touching the deck of the head.

Thing is, I turned that thing over numerous times in the months that I had it, and it never once felt like the pistons were contacting the valves or the head.

Borrow, or buy, a borescope and have a look in a couple of bores.

Mark.
 
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