Loud pop and now its missing BAD!!

[dieseldan2005]

at least your pistons are good. Hopefully no rod damage.

[240 spoke]

Hey do the valve stems show unusual wear? I have an 01 out of a shuttle bus that im getting ready to put in a car...I did a compression test and found the #6 cycl dead..The motor ran pretty well i thought for 206k...It turns out that I have a sicking valve...Some of the other stem show wear....If I put air in the cycl with the rockers off it would come out the exhaust port,,I smacked the echaust valve stem with a brass hammer with air on it and it stopped...Is it possible you had a valve stick and bend up the push rods? I did have a bent push rod on that hole....Ide check the valve stems and go from there...I tell ya the price of a head set and valves is crazy....They are going to the machine shop Friday....So much for mad money,Its gone...Let us know what ya find...See me MATT

[Deeslfxr]

At least have the heads checked over. You stated earlier that you couldn't move either valve on no.1. I assume that was because piston was at TDC? Also, I know this sounds stupid but when you did compression test, was that with good pushrods installed? I ask because one's mind can lose focus when their baby is sick. Russ

[daveyburt]

maybe get on the crank shaft with a breakerbar and watch the pistons go up and down while you turn. i think if you had a rod problem, it would be apparent. -#1 may not rise to the occasion.

just a thought, i really don't know but, good luck!

[Broncoguy]

Sorry guys, haven't been on in a couple of days.

I have the head off of the bad side, and when I move the crank by hand, it comes up to tdc like it should, so I think the rod is ok. The valves look ok, but unfortunately I pulled the head before I did a leak down check.

The valves move ok now, so the piston must have been at TDC when they hit before. The valve stems look ok, but that is with the naked eye, not any kind of measuring device.

The head gasket looked real good when I pulled it, and there is still cross hatch in all the cylinders. There's no lip at the top of the cylinder bore, and the pistons look great after a little cleaning.

I am going to roll the engine over and pull the pan and have look from the bottom. I am told the pan is sealed by RTV from the factory, so it doesn't cost anything to look.

I think my plan of action at this point is to have the heads checked at the machine shop, rebuild the injectors with a stage 2 kit from Rosewood and put wildman toons in it. Oh, and new gaskets throughout of course.

My only grey area is ring condition in the no compression hole? There were no push rods in that cylinder when I checked it, so could the valves actually seal tight enough to allow no air in to create compression? I would think I would have gotten at least SOME compression even without the valves opening.

Sorrt about the long post, just tryin to be detailed and get some good advice from you guys.

Thanks for all the replies.

[Deeslfxr]

No pushrods = no valve movement = no compression. Was there any signs of valves contacting piston? If so you need to find out why it happened. It would be surprising if the valves seized in the guides hard enough to bend/break pushrods only to free up when cooled down, but anything is possible.

[Broncoguy]

No signs of valve to piston contact at all. Only damage I can find is the pushrods. I guess it could have just been weak pushrods, but I find it hard to believe that both would go at the same time.

[orng1]

Bent pushrods or broken and you'll have 0 compresion. They are what keep the valves in their position.

I'd repair both heads, throw some new gaskets and pray it lasts a good while.

[Deeslfxr]

Originally Posted by Broncoguy

No signs of valve to piston contact at all. Only damage I can find is the pushrods. I guess it could have just been weak pushrods, but I find it hard to believe that both would go at the same time.

Yea, I would have to agree. When you take the heads in, tell them what happened so they can pay close attention to that cylinder. Russ

[Broncoguy]

Sounds like a plan, I'll post up what I find.

Thanks for the advice.