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

Sorry

https://youtu.be/bycMJ-opgn0

Definitely leaking compression.

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87 300SDL
87 190D 2.5NA 5sp
90 300GD with 606 turbo!
08 GL320 CDI
12 ML350 Bluetec
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Past rides:
82 300SD - the one that started it all!
81 240D
87 300SDL - the first one.
92 300D 2.5 Turbo
99 E300 Turbodiesel
07 E320 Bluetec
12 S350 Bluetec

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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Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k

Valve is not sealed when in closed position.

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Jim

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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1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

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 appreciate the opinions of what should’ve been done. Just looking for the possible cause of the issue. Thanks!

I will inspect!

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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97 e300d, 78 300Dt, 95 E300d, 94 E320 estate

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.