boy bent valves, thats exciting, musta over revved it.

 

OVER rev??? NO, run RPMs up to 2700-3000 yes while accelerating on hills.

 

thats what ususally bends valves in a engine.

 

Did anyone else drive it while you were on your trip?

 

Yes, my son, but I was in the passenger seat, and no he didn't over rev it, he didn't even get on it.

 

TIUSER,
Sorry about your engine problem . Whenever a V10 develops an engine problem we all V10 owners are concerned about it .Would you mind providing some more info , like are you the original owner (or know the maintenance history since new) ,how many miles on the odometer, what grade engine oil and what brand oil filter and oil change intervals used .


Wish you all the best,

 

Second owner, bought from original owner @ 108,000 miles 10 months ago. Don't know the exact maintanence history, but was told they had it serviced with the other vehicles in their fleet by their duty mechanic. They owned a landscape company and had a fulltime mechanic, this was the owner's wife's kid hauler, aka soccer mom truck. The truck was checked out by my mechanic and it was given clean bill of health, he said the truck looks like it has been maintained. The truck ran great until this incident.

 

The only thing that could bend valves is either the valve stuck in the guide and the piston hit it, or the valve spring is weak or broken and the piston hit it because of valve float.

While the engine is apart, take pictures of the pistons on these cylinders where there were "bent valves" - remember, we're just going on the mechanic's say-so at this point, or even second-hand info if you're talking to the owner of the shop and one of his employees is doing the job.

Take pics of the valves too, something sounds very strange if it was running so well and suddenly took a poop

 

[QUOTE=Krewat;] thing that could bend valves is either the valve stuck in the guide and the piston hit it, or ..)


Could it be caused by poor lubrication/no lubrication ?

 

I was not able to get pics. My mechanic is the one wrenching on my truck, he does have a helper and his helper is also a V10 Ex owner.


As far as I know, there was no piston contact, but I will know more this week, because it should be done.

 

TIUSER,
Any update? Do you know if the crack in the manifold was on the same cylinder that went bad?

 

Sorry, have been out of town. I had two valves that were bent, #5 and #10. #5 did make slight contact with the piston, but did not damage the piston. If #10 did make contact with the piston it did not leave a mark, so if it contacted the piston it was very slight. The crack on the lower intake was on same side as #5. #10 cylinder had compression and appeared to be functioning normally prior to the head removal, but during the valve job the #10 valve was not in spec so it was replaced. So, the two bent valves were closest to the firewall,#5 is the passenger side and #10 is the driver side. Coincidence ??


The exhaust studs on #5 side (passenger side) were repaired 10 months ago and there were 5 bad at that time. There were 5 bad studs this time too, not sure if they were the same studs or not, per my mechanic the wrong gasket was used in the previous repair. All totaled between both sides, 10 exhaust studs needed replacement during the head repair. Contributing factor to bent valves???




I have had the truck back for about two weeks and put about 400 miles on it with no problems so far.

 

I was just wondering if the crack in the manifold let those cylinders run too lean damaging the valves.

 

I can't say for sure.

 

That would be my bet. I had a 4.6 one time loose a vacuum line under heavy throttle. 10 seconds of hard pinging before I got out of it and it had broken rings on 3 cylinders.
Floating a valve with over rev isn't a problem normally on the modular engines. You can usually go well past anything that could be considered a normal RPM for awhile without any damage.