Alex_M
Full Access Member
- Joined
- Sep 27, 2021
- Posts
- 370
- Reaction score
- 674
Hey all! Hopefully one of you can chime in and confirm or deny my diagnosis.
2002 6.0. Just installed a ton of new parts - heads, cam, lifters.... Injectors.... Allegedly "genuine" AC Delco Made in Germany. Well upon closer inspection after the fact, they shipped from China. Fake Delco injectors.
Anyway - got the engine back together and running. Was smoking some so I shut it down. When I started it again it started to crank, kicked, and stopped dead. One injector had leaked down and filled the cylinder with fuel. Pulled plugs, cranked over fine, cleared out fuel. I reinstalled the original injectors (so much for being proactive) and restarted the motor. I now have a ticking.
I am familiar with both bottom end and top end noise. This one is odd, somewhere in-between, but seems fast for a top end noise. So here I go, crossing my fingers for a bent pushrod. Pulled valve covers and no such luck - all good. Started with valve covers off, nothing obvious. Noise is no louder.
Here's the kicker. I did a compression test on all 8. 7 of 8 showed 175-180 PSI. Cylinder 3 which was full of fuel showed 150#. All 8 were leaking off at roughly the same speed, nothing wildly out of line.
So, here's where my logic goes. If it were a bent valve, it would either leak down much faster or it would show zero compression. Since cylinder 3 leaks down at the same speed but shows lower compression, that rod is most likely bent.
By the end I will at a minimum pull the head and check the valve as well as measure piston to deck height to confirm diagnosis, but in the mean time I'd love input on this, possible alternatives. Thanks guys
2002 6.0. Just installed a ton of new parts - heads, cam, lifters.... Injectors.... Allegedly "genuine" AC Delco Made in Germany. Well upon closer inspection after the fact, they shipped from China. Fake Delco injectors.
Anyway - got the engine back together and running. Was smoking some so I shut it down. When I started it again it started to crank, kicked, and stopped dead. One injector had leaked down and filled the cylinder with fuel. Pulled plugs, cranked over fine, cleared out fuel. I reinstalled the original injectors (so much for being proactive) and restarted the motor. I now have a ticking.
I am familiar with both bottom end and top end noise. This one is odd, somewhere in-between, but seems fast for a top end noise. So here I go, crossing my fingers for a bent pushrod. Pulled valve covers and no such luck - all good. Started with valve covers off, nothing obvious. Noise is no louder.
Here's the kicker. I did a compression test on all 8. 7 of 8 showed 175-180 PSI. Cylinder 3 which was full of fuel showed 150#. All 8 were leaking off at roughly the same speed, nothing wildly out of line.
So, here's where my logic goes. If it were a bent valve, it would either leak down much faster or it would show zero compression. Since cylinder 3 leaks down at the same speed but shows lower compression, that rod is most likely bent.
By the end I will at a minimum pull the head and check the valve as well as measure piston to deck height to confirm diagnosis, but in the mean time I'd love input on this, possible alternatives. Thanks guys