So any idea yet of what caused the valve guide to wear out like that and cause the valve to not be able to seal?
I know you mentioned the crack, or what you think is a crack at this point, but how would that relate to causing the guide to wear out and become that loose?
Sorry im still learning so I apologize if I missed something that was already mentioned or coming off as a newb!
Zwilson, no worries you really don't need to apologize,for not knowing and being willing to learn from whats happened here.
We are all here with differing levels of knowledge and skill and can always learn more. Never ever be sorry or apologize for being willing to and wanting to learn.
Please ask away and I will answer any questions I can and so will other members here!
Guide wear is something that comes with either MILEAGE or with TIME/HOURS of engine operation, this truck was moderately low miles, when I got it 197000 miles original however one caveat, it was used as a service truck for a logging company and IMHO sat idling away for hours at a time in the bush.
This continuous idling will wear items out as well.
The thrust of the rocker against the valve induces a sideward thrust that wears out guides in time or miles as mentioned.
As hot exhaust gasses pass over an open valve that super heats the edge of the valve and when it closes it transfers heat to head. This is one of the reasons HI EGT can have a negative effect on these engines. IT can and IT WILL destroy pistons and valves in short order!
The crack came from heating and cooling and contacting the valve seat in an uneven manner causing hot and cool spots on the valve making it more susceptible to cracking or other damage.
As the guide it self wears and more exhaust passes up the stem, there is more and more soot causing the oil to become abrasive and wear the guide faster exacerbating, the pre-existing condition and making matters worse.
Had I been able to get a set of heads done valve grind and so forth in time I could have saved this engine, and it would have been a very good runner based on the compression values I achieved with my tests.
In essence the cracks came after the guide wore out not before the guide wore out.
Al....
What you described is what it looks like. I'm was going to think that head with the busted valve as oem and the other side had been replaced once. But maybe not...
Any chance you can get the depths the valves are set into the heads as a benchmark for further ideas. Might be a one only failure too but wont know till the other valves come out. It looks like number 6 exhaust is leaking something black out the closed valve. Was the valve seal gone or have you gotten that figured out yet. What shape is the valve rotater in. It appears you have not removed it yet. If that froze up the valve will pound the seat in short order. Still some investigation to do.
Thanks Gary for that, I'm pretty certain I can get more info.
Gary you know I won't settle for less than full disclosure of all results, however I've got other things to do, I'll be pressure washing the head and inspecting it further...why handle a dirty filthy head right? Also once I've got that block pulled out I'll more carefully inspect it. I would like to salvage as many usable parts as I can from it, bearing caps, seal plates and so forth. I'll be doing a further post mortem on the block to inspect the crack as well.
Al findings will be recorded in this thread so ya'll gotta be patient with me.
I'm needing some time now as I may have a good running engine located and deal is at this time made for trade...just gotta get wife to say OK!
Thus if ya'll are patient you will have more info, the video was just the start of the post mortem but was needed for closure and so people who have CHUFFERS will take heed and NOT let their engines get too far along. I don't want to see anyone else go through this level of failure as I have!
Thanks for reading
Al
