Ok gearheads who here knows anything about 7.3L Ford Power Stroke diesels. I have a customer with a 97 7.3L and it keeps bending pushrods. Exhaust pushrods and even broke a rocker arm once. Ive scoured some ford forums and had a friend look for TSB's and have found nothing.
I know the driver of this thing abuses it so I suspect an overspeed condition but the last time it happened (a couple of hours ago) I dont think he had the opportunity to really trash it.
Any of you guys run into this problem?

Unless he has dorked with the IP speed govenor I don't think overspped would be a problem. Has the block and head ever been milled such as for a rebuild or due to a head gasket failure? If too much was milled it is possible the pushrods are now too long. I believe this motor also has hydaulic cam followers. Is the oil pressure within proper range? I wonder if too high of oil pressure, say from the a bad bypass flow not opening causing problems with the hydraulic lifters?

TimK

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Here's what you do if it's so cold your diesel fuel gels. Smear some on some toast and stay inside until it warms up outside.

Does any PERFORMANCE MODS ON THE ENGINE? With TODAYS electronically CONTROLLED Diesels, more hp is just a plug in! Does he have an ehxaust brake? The performance mods could change his engine governed speed. He could be over-revving it. If the ehxaust brake restricts too much and the guy didn't have heavier ehxaust valve springs installed, A valve can stay hung open and get hit by the piston. This was an issue with earlier, 12valve Cummins diesels in Dodge trucks.
This guy sounds like he just hasn't suffered enough in the pocketbook yet to take his RIGHT foot off the floorboard!!!

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No exhaust brake on this truck. But it has an exhaust back pressure regulator. It closes a flap in the exhaust to aid in warm up. It's stock. It has happened on the same exhaust valve 3 times. I'm beginning to wonder if its a weak valve spring.

I don't think it's particularly applicable to this situation, as it sounds like you have a problem specific to one valve, but remember, either electrical or mechanical, a governer only affects the speed you can power the engine up to. If equipped with a manual transmission, one can always over-rev an engine by downshifting incorrectly.

I've seen several engines, both gas and diesel, destroyed in this manner. And each time the customer said "I thought the computer/governer would keep it from over-revving". Apparently they were under the impression that new control systems were not only able to control aspects of the vehicles engine and other systems, but able to control the laws of physics as well. While some new systems almost seem like it, flirt with the idea of it, none have managed to defy physics yet.

MV

I just re read my post. It's just the exhaust pushrod on number 8 that does it. I'm gonna pull the valve spring and have a look. Maybe sticking in the guide or a broken valve spring.

I bent a few pushrods and broke a couple of rocker arms, but it was the combination of too much fuel. I was using injectors that were 30% rich ( and timed wrong I might add) and propane. I really think the problem that I had was the injection duration was too long, thus, the fuel was burning longer than it should have in the cycle. It did it during a down shift to pass at 65MPH....

It did make lots of noise......

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