No compression 6.4

[Alexjob]

I hav an 08 f350 SuperDuty power stroke I just got done doing a full rebuild on the motor and it has no compression in any of the cylinders. Dose any one have any experience with this?

In the rebuild new pistons, rings, pushrods, rocker arm assembly, all bearings and head studs.

 

[troutwest66]

If it's all of them then I'm thinking something in the valve train not letting one set of valves close. With the newer engines maybe there's something else that could also do this?

 

[01yellerCobra]

There's really only a couple of things that can cause this. One of them being you forgot to put all the piston rings in. Which I'm going to guess you didn't forget those. Next would be head gaskets instslled incorrectly. But unless you didn't torque them down you'd have compression somewhere.

My guess is going to be the cam was installed incorrectly. Especially if these are interference engines. All it takes is one spin with the starter, pistons and valves make contact, valves are now bent, which means no compression across the board.

Have you tried a leak down test?

 

[Alexjob]

There's really only a couple of things that can cause this. One of them being you forgot to put all the piston rings in. Which I'm going to guess you didn't forget those. Next would be head gaskets instslled incorrectly. But unless you didn't torque them down you'd have compression somewhere.

My guess is going to be the cam was installed incorrectly. Especially if these are interference engines. All it takes is one spin with the starter, pistons and valves make contact, valves are now bent, which means no compression across the board.

Have you tried a leak down test?

What is a leak down test not familiar with that term. One of my thoughts was if the lifters were over pumped it would hold the values open but they should have bled off my now or if I got sent the wrong push rods that were too long, but the lifters should take that up shouldn't they??

 

[01yellerCobra]

What is a leak down test not familiar with that term. One of my thoughts was if the lifters were over pumped it would hold the values open but they should have bled off my now or if I got sent the wrong push rods that were too long, but the lifters should take that up shouldn't they??

A leak down test basically pressurizes the cylinder with air. If there's a leak you can figure out where it is by where the air is coming from. If it's the valves you'll hear either from the intake or exhaust. Or both if it's bad. If you hear it coming from the oil dipstick tube it's something with the rings.

It would depend how long the push rods are. There's only so much movement in the lifter plunger. Did you compare the new push rods to the old? Normally something like the lifter issue would affect one or two cylinders. Not all of them. So you're looking for something common to all cylinders.

 

[Alexjob]

A leak down test basically pressurizes the cylinder with air. If there's a leak you can figure out where it is by where the air is coming from. If it's the valves you'll hear either from the intake or exhaust. Or both if it's bad. If you hear it coming from the oil dipstick tube it's something with the rings.

It would depend how long the push rods are. There's only so much movement in the lifter plunger. Did you compare the new push rods to the old? Normally something like the lifter issue would affect one or two cylinders. Not all of them. So you're looking for something common to all cylinders.

I figured out I have the crankshaft 180 off of the cam. Tear it apart next week.

 

[EK410]

I figured out I have the crankshaft 180 off of the cam. Tear it apart next week.

Just pray that you didn't bend any valves and or pushrods. Being 180 off you will be lucky if there isn't any damage. Let us know how it turns out.

 

[Alexjob]

Just pray that you didn't bend any valves and or pushrods. Being 180 off you will be lucky if there isn't any damage. Let us know how it turns out.

Bent all most all the valves push rods are fine. Waiting for parts to get it back together.

 

[EK410]

Bent all most all the valves push rods are fine. Waiting for parts to get it back together.

Well that stinks. Good news on the push rods. Good Luck