SLOWEST Z

what is the reason for lifters failure? Can it be due ro failure of oil pump that leads to lack of lubrication?

how can the healthiness of oil pump be checked? does the oil pump normally fail in the C6Z ? My car has around 70k miles

Dan_the_C5_Man

The prevailing theory is that these cam and / or lifter wheel failures are due to a lack of proper surface hardening, not due to a lack of proper lubrication.

The interesting thing about the design of the LSx oil pump is that it can't really "fail" per-se.. What can happen is the blow-off valve gets clogged with junk from the initial machining operation or wear over time and causes the valve to stick open, which results in zero pressure build-up, and a "failed" oil pump..

If the pressure release valve ever became clogged and stuck, you could potentially pull the pump off, disassemble and clean, put it back into service for another 100,000 miles.

My recommendation is anytime you have the front of the motor off, let's say to do a cam swap, it should just be part of the process to disassemble the oil pump, clean out the inevitable machining shavings that will be trapped in the blow-off valve area, reassemble and install.

outhouse

Residue or debris can also stick in the actual valves valve, causing a collapsed lifter. Improper preload can also lead to this.

SLOWEST Z

Thank you for the helpful info