help, what did i break?

G

getblown5.9

Ceritified Kleenex Dealer
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Aug 3, 2006
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Over the last 6 weeks i had the head completely redone, all the valves, seats, guides, o-rings, marine gasket, head studs, and a drag comp upgrade. ive only had the truck running for 5 days...

I've just been trying to get it broken in and running good after all the money i put in the head and tonight something went wrong. i have the wastgate set back at 40psi, and was doing about 70-75 on my way home tonight when a car came off a ramp pretty quick. i get on the loud pedal a bit to move up and get him some room to merge. i was at full throttle (my stupidity) when the exhaust goes POP POP POP POP POP like a really bad back fire. so as im cruising home i notice there is still some blub blub blub blub noise in the exhaust, no engine sounds, nothing up front, its only coming from the stacks. whatever it is that is broken (valve, gasket again, bad piston) can not be heard over the normal engine rattle. the pop or blub sound at the stacks can be heard easily from idle and when i popped the hood with it idling you can hear that same BLUB BLUB BLUB at the AFE intake, but no excessive valve noise etc.

the truck has lost ZERO power, i gave it a 3/4 throttle blurlp on the way home and the power is still there like normal, boost like normal, EGT's normal.

so what do ya think, exhaust gasket leak, valve/pushrod bent, turbo, head gasket leaking and losing compression? i mean there are no codes to tell me anything and the only way i know something wrong is by this new (and kinda cool sounding) burping in my exhaust.

sorry for poor quality, its a cheap digi-cam

video 1- idle next to intake then move to the stack
http://s97.photobucket.com/albums/l208/maddawg0517/?action=view&current=IM000022.flv

video 2- cruising, getting on the loud pedal slightly to hear the noise change with rpms
http://s97.photobucket.com/albums/l208/maddawg0517/?action=view&current=IM000021.flv
 
i would pull the valve cover and check valve lash, and make sure that everything is snug and with in specs. I have heard the same sound come out of the the intake in a 3rd gen after some motor work. turned out to be 1 valve was way out and the valve cross bar eventually fell off while we were letting it idle. easy stuff first. that head will settle a lot for the first few weeks, many retorques to insure it is seated properly.
 
found it...

hopefully pushrods are only about $10-12 at cummins, this one is the number 3 exhaust valve. the number 1 exhaust valve pushrod was so slightly bent you can barely see it wobble when rolling on a table so im gonna buy 2 pushrods and put it back together tomorrow.

98483.jpg


98484.jpg
 
Should be good to go with new push rods.

I broke the exhaust pushrod of #3 and drove it for 30 miles to the shop. When I looked around there was a 1" piece of the top of the pushrod laying in the oil under the rocker... and the intake pushrod was bent so bad I had to bend it straight so it would come out of the hole.

While you are in there I would suggest looking for WHY it bent. Mine was from the lash being a little tight when I was playing and evidently the pushrod didn't like the piston slapping the valve. Musta broke something. Took a day or so before it let loose.

Anywho. Long and short... I think the pushrods are 3 bucks apiece. ;)
 
Glad you found it, and it's a fairly cheap and easy fix :rockwoot:
 
Damn, why would that happen?

Really inquiring minds want to know.

dan
 
99% improper installation, running the engine with the valve cover off and the valves still seemed to open/close fine (no hanging up, or other problems) on #3, but there was alot of valve rattle due to the slack of a shortened rod. this also was causing the slight gurgle in the exhaust note due to the valve only partially opening
 
How do you install a push rod improperly?
Seriously, always thought push rods were a no brainier. Is there a ledge they can sit on just above the lifer allowing it to fall in place later?
I've never had one of these apart but I'm sure it will happen sooner or later.

Thanks for the info and sorry for your luck there.

dan
 
yes, the top of the lifter has a "bowl" that it sits in, mine wasn't all the way down in when set the lash. thus making it very loose when i fired the engine and it fell into place. it didnt cause a problem for me until i decided to be dumb and hammer just a little too hard and take it past 3k rpms
 
Moral of this story is to recheck valve lash after the engine has been run. Having said that it would have happened to me as well most likely LOL
 
oh yea, i found also on cylinder number 1 the pedestal that the rocker shaft sits on was damaged somehow. the rocker fit really tight over it so i was checking it out and noticed it was cracked at the corners. ordered a new one, being delivered direct from Cummins by 10:30 tomorrow. its another day of down time, but another possible problem that i luckily caught before it could break and send metal bits into the engine for greater damage. plus the part was only $5.19.

anyways, it will go in tomorrow, and get started, idle for about 30 seconds, then shut off and valve lash rechecked just to be sure.
 
Sounds like a damn good idea to me, and I KNOW it sounds like a damn GREAT one to you LOL
 
Here's a good suggestion for you, remove the rockers, and pedestals, to check for gouging in the rocker shaft surface. I found some binding in my rockers because of this, and had rockers and shafts that were all gouged up.......:doh:
 
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