while tring to tune my fuel pressure, pretty sure cracked a piston

[78f100]

just finished the compression test, it is not a cracked piston. All the rockers look good and all cycle correctly, I had my son spin it over while watching them. I compared my ccv to my brothers 6.4 with about the same miles and its about the same, it looked like alot to me but I guess its not.
I wonder if its a injector knock or a bent pushrod. Like I said all the rocker arms appear to fully cycle but thats just eyeballing it, I have never bent a pushrod in anything so idk, will it knock like that?

edit.. I started thinking it may be in the bottom end after th comp test but that wouldnt explain the smoke..
thanks for the help and prayers (dozer's diesel) yall keep the ideas coming I have a lot to learn.

 

[bigrpowr]

Yes it will. Pushrods have been known to be an issue so it's very possible. If it was a piston you would have known instantly. Oil smoke is obvious.

 

[davey99ps]

I can't watch your vid, but when I lost the o-rings on 2 of my injectors it knocked really bad. I realise they're 2 different motors, but if you have an injector dumping excessive amounts of fuel in that cylinder it can make some bad sounds. I'd maybe pull your injectors an have them checked out. Hope its something somewhat simple for you, good luck

 

[907DAVE]

Drop that cylinder via scan tool and see what happens.

 

[Dzchey21]

I'm surprised you don't have a contribution code...


It could also be a bad lifter making noise. My Yukon just dropped a lifter randomly Two Weeks ago sounded like bottom end. i'm not going to say how I fixed it but I didn't replace the lifter


Jared at rcd was saying in another thread how the lifters are known to fail,maybe he has some insight on how to diagnose

 

[bigrpowr]

Shouldn't have said that thing was trouble free.

 

[78f100]

I didnt pull the lifters during the hg install and honestly cant remember if they can be changed without pulling the head, I know the hg has cutouts for the pushrods. Can you pull the lifters without pulling the head?

 

[White_monster]

Heads have to come off to change the lifters.

 

[08PowerSmoke]

I thought the same thing with mine....Excessive CCV pressure....enough white smoke to where sitting still in traffic it looked like a fire and there was a knock too.

I had a leak in the fuel rails at the end cap....it was dumping fuel in the crankcase almost 4 gallons worth! Which caused excess pressure and thinned the oil enough to where there was excessive noise.....IF it happened while you were tuning the air dog it might be the problem. Fuel pressure caused a leak that normally wasnt there.....

Easiest check.....take some old oil jugs and change the oil....ONE if it smells like fuel TWO if you have more oil than supposed too you could have the same thing.

 

[bigrpowr]

Heads have to come off to change the lifters.

God damn right. Blows.

 

[78f100]

S

I thought the same thing with mine....Excessive CCV pressure....enough white smoke to where sitting still in traffic it looked like a fire and there was a knock too.

I had a leak in the fuel rails at the end cap....it was dumping fuel in the crankcase almost 4 gallons worth! Which caused excess pressure and thinned the oil enough to where there was excessive noise.....IF it happened while you were tuning the air dog it might be the problem. Fuel pressure caused a leak that normally wasnt there.....

Easiest check.....take some old oil jugs and change the oil....ONE if it smells like fuel TWO if you have more oil than supposed too you could have the same thing.

Oil level is right where it stays, looks and smells good, thanks though.
I am gonna pull the rockers tonight first then probably injectors.

 

[08PowerSmoke]

S

Oil level is right where it stays, looks and smells good, thanks though.
I am gonna pull the rockers tonight first then probably injectors.

Oh well I tried.....one of the rocker arm tips was worn on mine too! I replaced the assembly's on both sides.....keep us informed curious to see what the problem is!

 

[78f100]

Mine were worn also, I replaced both assemblys too. I reused the pushrods though.

 

[kyle43335]

subed

 

[78f100]

I got her fixed boys, thank the lord ! I tore the drivers side down to the head and all looked good, pushrods rockers, bridges couldnt find anything. I was pretty sure it was cylinder 4 from the ae test so pulled all 4 injectors. They all looked good but I went ahead and put my 60hp nozzle in a spare injector slapped it in hole 4 and it runs great with no knocking. I still have to resolve the rp issue but she is running, we just got back from testing it out.

 

[Dzchey21]

Nice!

 

[strokin08]

That's good man, glad to hear.

 

[madman1234509]

I got her fixed boys, thank the lord ! I tore the drivers side down to the head and all looked good, pushrods rockers, bridges couldnt find anything. I was pretty sure it was cylinder 4 from the ae test so pulled all 4 injectors. They all looked good but I went ahead and put my 60hp nozzle in a spare injector slapped it in hole 4 and it runs great with no knocking. I still have to resolve the rp issue but she is running, we just got back from testing it out.

What do you mean by ae test? Just for future reference in case anyone has a similar problem and needs to know what or how to test for this?

 

[78f100]

What do you mean by ae test? Just for future reference in case anyone has a similar problem and needs to know what or how to test for this?

sorry,auto enginuity cylinder contribution test. It reads the crank shaft speed as it fires and puts it on a graph, you can see a little of it in the video but its kinda hard to tell.

 

[Erikclaw]

That is a great result! Good to hear it wasn't a lot worse.