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  #1  
Old 02-22-2019, 04:33 PM
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What Causes This Issue? OM606 Video Included

I installed this head. It had two bent intake valves in the cylinder making the noise. I just scavenged two from another head and lapped them into the seat. Was hoping for an easy inexpensive repair. Apparently not! Maybe there was damage to the valve seat that I couldn’t see for myself? Maybe? What say you?

Kevin


Last edited by oilslick; 02-23-2019 at 04:11 AM.
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Old 02-22-2019, 04:33 PM
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Forgot to load the video.

Sorry

https://youtu.be/bycMJ-opgn0
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  #3  
Old 02-22-2019, 05:39 PM
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Definitely leaking compression.
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  #4  
Old 02-22-2019, 06:17 PM
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You can hear the compression leak/misfire. Most likely damaged the seat. Should have taken it to a machine shop to have it evaluated at minimum for slapping the head back on. What caused the two valves to bend? Exhaust and intake on the same cylinder bent?
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  #5  
Old 02-22-2019, 08:24 PM
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Valve is not sealed when in closed position.
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Old 02-22-2019, 08:35 PM
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Machine shop time, hate to be that guy but it should of went there the first time.
Injectors are the same, send them out or prepare for a headache.
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  #7  
Old 02-22-2019, 10:05 PM
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What caused bent valves the first go around?

Is the most forward valve on cyl 6 the only one blowing back?

With the engine off and valve off the lobe, shine a light in the port and see if the valve is being held open. I've had lifters expand when an engine is apart and they need to bleed down before the valves fully close.

Pull the valve cover and make sure the intake valves are not being held open by the cam / lifter / broken valve spring.
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Old 02-23-2019, 04:15 AM
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Thanks!

Quote:
Originally Posted by engatwork View Post
Valve is not sealed when in closed position.
I appreciate the opinions of what should’ve been done. Just looking for the possible cause of the issue. Thanks!
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Old 02-23-2019, 10:27 AM
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Thanks!

Quote:
Originally Posted by 97 SL320 View Post
What caused bent valves the first go around?

Is the most forward valve on cyl 6 the only one blowing back?

With the engine off and valve off the lobe, shine a light in the port and see if the valve is being held open. I've had lifters expand when an engine is apart and they need to bleed down before the valves fully close.

Pull the valve cover and make sure the intake valves are not being held open by the cam / lifter / broken valve spring.
I will inspect!
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  #10  
Old 02-24-2019, 09:07 PM
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Did you look at the seats after lapping? Sometimes the get so recessed that the lifters can't compensate. Always seems to be the 5th or 6th cylinders that have this problems on these 606.91X motors
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Old 02-26-2019, 07:19 PM
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Actually...

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Originally Posted by bigpanda16 View Post
Did you look at the seats after lapping? Sometimes the get so recessed that the lifters can't compensate. Always seems to be the 5th or 6th cylinders that have this problems on these 606.91X motors
When I was lapping those valves it did appear that the seats were more recessed than the others. It’s going to be rebuilt and hopefully all will be well. Thanks for the insight.

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