We have not got the front off yet but are thinking the cam is off time somehow and that bent the pushrods - anybody got any experience with that one.

not really sure how if could change timing on the cam, given they're gear-driven.. unless it shed a couple teeth.. KDP? just thinking out loud here..

I have seen instances where too much fuel in the cylinder has caused that to happen. but it is generally acompanied by bent connecting rods as well. The only way to know for sure is to pull the head. Chances are bent pushrods are not all thats wrong.

Hydro-locking would definitely do it, as well. But like you said, usually con-rods will suffer, as well.

Misadjusted valves can cause it as well as engine overspeed. Ether is always a good one for that if it was overloaded with it, I have seen ether be the culprit many times, basically has the same effect as hydrolocking.Does he have any engine modifications we need to know about like Methanol or propane injection or higher rpm governor springs ect?

No modifcations only after market air and a big plate

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Can you give me a more specific idea on hydrolocking??

Something has physically broken the cam gear and not the KDP....How about the rear timing cover with too much flex........?

How much black smoke will it take to give this a hydrolocking problem? We are running a trailer at around 70 mph climbing a hill and just cresting ... not a along pull really, basically just going down the freeway.

What are symptoms of hydrolocking? Does the problem with hydrolocking usually come from the pump itself?

We are wondering about any distortions from the weight being held by the timing plate,, seems like alot of weight on the plate. Is there something better for a plate or are we up the wrong creek. The Gear on the cam is completley broke at the spokes. Kdp in tact has not moved. We do have much smoke at all out of this truck. And we believe our connecting rods are fine. So are ruling out what we know about hydrolock.

Please respond.....

I've seen hydro locking on Marine engines where water flowed backward up the wet exhaust into the exhaust manifold & through an open valve. (The boats were trying to play submarine at the time.) We (the Marina) saved it from sinking & informed the owner. When the owner turned hit the starter, the cylinder came up on a cylinder full of water. It might even have fired one before doing so. When the cylinder came up on the incompressible fluid, it bent the connecting rods all to crap. In a land vehicle, the only thing I could think of would be a blown head gasket, cracked head, cracked intake (water jacket). Another possiblity, is / was a hung valve at some point. I've had it on a gasser. The piston came up & slapped the hung valve which broke the rocker arm & spit out the push rod.

I think we need more info from the OP...........especially since he posted in the 3rd gen section of an '03 common rail having a kitty. Now this!!!!! Until he posts in his signature what year, mods, etc. he has on his truck..........we may be dealing with a rookie.......or a troll.Had to be said.......I sure hope it ain't true!!!:cool:Carry on!!!

Overspeed comes to mind. Like grabbing 2nd instead of 4th for deceleration at 45 mph. I don't have the specs on the 12V, but the 24V ISB is rated at 4200 rpms for 15 seconds.. so it takes a decent overspeed.

What would Symptoms of a bent pushrod only be ?

  JOHNFAK said:

What would Symptoms of a bent pushrod only be ?

It could be anything from no power, knocking, screaming EGTs (depending on what one was bent), or any combination.

or no compression

Need a signature with the truck. The OP needs to give us some better information. Is it just bent pushrods on #6 or are all 12 bent? To my way of thinking these are conclusions someone has made... or jumped to... but skipped giving us the full information of why this was suspected. If we try to figure to out to help with partial data, and are later found to be wrong when it's torn down, we look like chumps (chimps). Russ

  AH64ID said:

It could be anything from no power, knocking, screaming EGTs (depending on what one was bent), or any combination.

thanks I remember stuffing up on a valve lash ........... really made the truck run bad ..... only for 10 seconds .... but always wondered if I could have slightly bent a pushrod ....

Back to what could have broke the cam ring, To explain hydro lock is when there is too much other stuff wether it be a vapor from ether or a liquid from a bad injector or coolant from a cracked head or bad head gasket fills the compression chamber and it can not compress it and the valves try to open against this and can not causing the damage.I am also thinking one of two things as well an oversped and or a valve broke or dropped and caused it to happen. If all of them are bent I would pull the head and look for other signs of damage like broken valves and valve to piston contact.

  Wild and Free said:

Back to what could have broke the cam ring, To explain hydro lock is when there is too much other stuff wether it be a vapor from ether or a liquid from a bad injector or coolant from a cracked head or bad head gasket fills the compression chamber and it can not compress it and the valves try to open against this and can not causing the damage. I am also thinking one of two things as well an oversped and or a valve broke or dropped and caused it to happen. If all of them are bent I would pull the head and look for other signs of damage like broken valves and valve to piston contact.

We used a 93 and added a p-pump about a year ago and put it back into my 94. The cam gear is what actually broke all the way around the shaft. We are suspecting the cast iron gear from the 93 not being able to handle the P-pump from the 94. The 94 had the steel camgear. We did not notice it when changing things over. We have a 94 camshaft from the original engine that is larger the 93 by quite a bit. Anybody have any experience with problems using 93 gear with the 94 pump?