chev4x4455
Registered Member
I have a friend with a 5.3 in their Suburban. It was missing with a code ''po300'' which is a randon cylinder missfire. I isolated it as a cylinder #6 missfire. It had 280,000+ missfires. (Strange that it did not have a code ''po306'' meaning cylinder #6)
Anyway I found a broken exhaust pushrod. In order to get the broken peice out of the motor, you must pull the cylinder head, unlike the older small blocks. I was able to check the valve with the head off. Its not bent of stuck in the guide. The lifter is not colapsed. Unknown why the push rod has broke.
I had a simular problem on a Ford v10 last week, but it was run low on oil and the lifter had bled down, allowing the rocker arm to fall off, wedging into the valve and bending the valve.
Has anyone experienced this in a 5.3? I guess I'll just put it together and see what happens. It will probably be just fine.
Anyway I found a broken exhaust pushrod. In order to get the broken peice out of the motor, you must pull the cylinder head, unlike the older small blocks. I was able to check the valve with the head off. Its not bent of stuck in the guide. The lifter is not colapsed. Unknown why the push rod has broke.
I had a simular problem on a Ford v10 last week, but it was run low on oil and the lifter had bled down, allowing the rocker arm to fall off, wedging into the valve and bending the valve.
Has anyone experienced this in a 5.3? I guess I'll just put it together and see what happens. It will probably be just fine.
