Diagnosing Power Stroke Intake Thump During Delayed Start

By -

If one simple problem leads you to a full-on rebuild, you might be a Ford truck fanatic!

When you own any sort of vehicle, you know problems are inevitable. But the worst kind of problems are the ones that don’t have an obvious solution. Such was the case with an understandably frustrated FTE member who goes by the handle TooManyToys after his 6.0-liter Power Stroke Super Duty started giving him fits recently.

“Post Christmas the truck may not travel for months, but to keep the turbo clean I get a run around the block every 1-2 weeks. With my neck really bothering me lately it sat for 3-4 weeks. So during a delayed start I heard something, then stopped. Set up the iPhone and jumped the starter. Jumping isn’t going to engage the injectors. 

I took the iPhone video inspection so I could review it on the big screen to see any details. Don’t see excessive looseness that would be a bent pushrod or issues with the rockers, although there may be one. I really haven’t had to get deep into a 6.0, so if there is something subtle I may miss it. Considering the delay start and thump went away with starting, maybe it was a case of a lazy valve from not running. Maybe. Any thoughts from others who have been into this motor?”

Power Stroke

As the OP notes, this generally signals a pretty big problem.

“That kind of compression back into either the intake or exhaust typically associated with bent pushrods or damaged rockers. I can’t blame the injectors without the FICM engaged. Prior to this thump, the plan was check for a slightly bent pushrod that when the oil is hot and thin may be causing a valvetrain tick, and replace the even bank of injectors to the IDS charts.”

Of course, many others in the FTE community have dealt with similar problems, as Copper.Farm notes.

“I’m cross linking to this thread in 6.4L because speakerfritz has an excellent description of the thumping, he has rebuilt the rockers and replaced the push rods in his truck. The thump in your video is very pronounced. Could be intake valves not opening enough.

This would be the first time I’ve heard of the rockers/push rods going on a 6.0L. It seems more common on the ’08 6.4L. As you build up your research, it is my understanding that the rocker part numbers are now the same for 6.0L and 6.4L. Also, there is a special torque sequence for 6.0L vs 6.4L. Here is the detailed thread.

Brett Foote is a longtime contributor to Internet Brands’ Auto sites, including Chevrolet Forum, Rennlist, and Ford Truck Enthusiasts, among other sites.

Comments ()