Knock sensor or dealer copout?

[MonteC]

Originally Posted by schardbody

they want no part of the truck anymore because they are worried about public humiliation when they cant figure out the problem......

like someone else said if the computer doesnt spit out a specific problem that localized to a very common problem then they are stumped.

the VERY second thing done should have been a compression and leakdown test, while its likely it'll come back in spec it would atleast rule out a few things.

they wouldnt be able to diagnose a valvespring issue unless its obviously broken, my opinion is its likely just weak.

a bent pushrod would cause less power from that cylinder which would show up as a misfire (cylinder contribution) but i've never seen an LS bend a pushrod even when being over revved.

a lifter is another possible cause but you really wont know much without pulling the head and swapping them since its a higher RPM issue they/it is probably going to appear fine to the eye just like the valve spring....


be glad they decided to send you packing, they never would have figured it out and you'd have a truck that was part swapped until they were fed up, because throwing parts at a problem is all they are capable of, even with all the technical support and equipment they are still incompetent....

I had two bent out of one engine. Bone stock.

[schardbody]

Originally Posted by MonteC

I had two bent out of one engine. Bone stock.

what caused them to bend? not trying to say it doesnt happen just saying i've never cured a driveability issue on an LS based engine by replacing bent push rods...

[MonteC]

Originally Posted by schardbody

what caused them to bend? not trying to say it doesnt happen just saying i've never cured a driveability issue on an LS based engine by replacing bent push rods...

I have no idea. I bought the motor with 89k miles on it out of a fbody parts dealer. Put it in my monte carlo and pulled the valve covers to change springs and found two bent pushrods. Was attached to a six speed if that makes any difference.