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P0036 and no compression in cylinder 6

wrd1972

Full Member
Joined
Jul 19, 2013
Messages
94
While passing another car on the highway, the engine rev'd to its acceptable highest RPM, up-shifted and then I had a P0306 code show up. After investigation, I have no compression in cylinder 6.

5.3 LC9 is bone stock with 190K miles. I have yet to start working on it but I am assuming it has a bent valve from smacking a piston at high RPM. I would love for it to be a broken valve spring but I dont really see how that can cause a compression lost without dropping the valve.

But my real question is, WHY did this happen on a bone stock engine? Is this a known issue?

Thanks. :)
 
what year avy?
 
Any ticking noise ???


The P0036 is a O2 sensor code.
 
I was hoping it was not that. more than likely it's a collapsed valve lifter. It is a known issue on some 07 -08.

Do a search on the site with the letters  AFM
 
Okay. So does this mean its unrecoverable and must be replaced?

Can I remove the AFM lifters and install normal lifters plus de-function the AFM in the PCM? Or are there additional parts that would need to be replaced to de-function the AFM?
 
Well you could replace the lifters and camshaft but at 190,000 miles it may be better to replace or rebuild it.


Summit Racing sells this kit.
https://www.summitracing.com/parts/cmb-09-0026/overview/

I've never pulled apart a motor with over 100,000 that did not have other problems. twisted connecting rods, bad crankshaft bearings etc
 
Thanks for the reply.
I think the plan will be to use a delete kit and tune it out. Engine runs fine otherwise...just cant afford a rebuild.

Whats the chances that the cam lobe would be damaged from the busted AFM lifter?
I have seen where others have had this happen but I hope it was in cases where lots of miles were driven while it was damaged. I put maybe 50-60 miles on it, in this condition. But obviously, I will check the lobe.
 
Pop off the valve cover and see how loose the rocker arm is on number 6 cylinder.
 
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