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+--- Thread: 617 valve lash (/showthread.php?tid=3143)
617 valve lash - larsalan - 11-21-2011
I may have asked this before but don't know if I got any valuable responses.
Adjusted my valves the other day because I thought the motor sounded kinda clacky.
I cannot have been 10,000 since I was last in there and yet every one of the exhaust valves was tight as could be against the cam. While every intake valve was right where it should be.
It this is how it pretty well always goes for me. That the exhausts are tight and intakes need no adjusting.
What does that tell you? Nothing? I guess I need valve adjust every 5k or 8k cause 10k is way too long.
RE: 617 valve lash - Hercules - 11-21-2011
Higher exhaust temps. could cause exhaust valve stretch.Higher rpm usage could also do same,and cause seats to beat -in. Valve adj. to be set cold,but below freezing to increase clearance. Nothing wrong with increasing clearance a small amount,and or adj.at less mileage.
RE: 617 valve lash - dieselboy - 11-21-2011
Mine were all in spec after 10k and I rev the piss out of my car with some decent egts.
RE: 617 valve lash - Hercules - 11-22-2011
You"re Question; What does tight exhaust (only) Say.IF each time only exhaust are tight. Not a normal condition! Almost always serviceable. Will be ok inless you run out of valve adj. thread. Why? tight. Valves stretching,valve seat area sinking in or both. No other possible reasons!
Quality, mileage,age ,temp.stress all plays a part. Soft cylinder heads do occur even on Mbz. (been there).
Why only exhaust side,++ add heat!
Keep those valves adjusted,---Roll On.
RE: 617 valve lash - larsalan - 11-22-2011
Time to get the FMIC on and help cool it off
and figure out this whole drip timing mystery.
RE: 617 valve lash - Captain America - 11-22-2011
(11-21-2011, 07:45 PM)Hercules Higher exhaust temps. could cause exhaust valve stretch.Higher rpm usage could also do same,and cause seats to beat -in. Valve adj. to be set cold,but below freezing to increase clearance. Nothing wrong with increasing clearance a small amount,and or adj.at less mileage.
I have read that low RPM High load is what causes seats to wear more? Something like there is more pressure closing against the valve than when there is a higher RPM.
I read that in a Mercedes Tech manual
RE: 617 valve lash - Hercules - 11-22-2011
Yes, lugging the engine High heat, high stress. Called severe operating conditions,(adjust valves more often). This condition usually found on trucks, buses, heavy laden vehicles. Higher, normal rpms will be less wear.