Valve question - PeachParts Mercedes-Benz Forum

psaboic · #1 02-21-2011, 11:17 AM

My teenage son came up with a decent question I thought I would post to the forum. When doing a valve adjustment on a OM617, do you need to do them in a certain order (i.e. cylinder 5 then 4, 3, and so on) or can you do all the intake first then the exhaust (Provided of course the cam is set to the proper position for each valve before you do it?)

He said he thought if you were able to do all the intake first, then the exhaust you would minimize the chances of screwing up the adjustment. For the life of me, I cannot think of any reason why it could not be done this way.

Anyone??

Stretch · #2 02-21-2011, 01:50 PM

Quote:

Originally Posted by psaboic

My teenage son came up with a decent question I thought I would post to the forum. When doing a valve adjustment on a OM617, do you need to do them in a certain order (i.e. cylinder 5 then 4, 3, and so on) or can you do all the intake first then the exhaust (Provided of course the cam is set to the proper position for each valve before you do it?)

He said he thought if you were able to do all the intake first, then the exhaust you would minimize the chances of screwing up the adjustment. For the life of me, I cannot think of any reason why it could not be done this way.

Anyone??

This is fine - do what ever you find easiest. Some people insist that it is important to adjust in a certain order but all you really need to ensure is that you adjust the clearance when the cam lobe is not near to the follower.

When adjusting valves it is best to leave them on the looser rather than the tighter side.

If you want to see measurements of the cam have a look here:-

http://www.peachparts.com/shopforum/showthread.php?t=290268

This is for a non-turbo cam, but I understand the turbo one just has a higher lift ~ 10mm

tbomachines · #3 02-21-2011, 01:59 PM

Doesn't matter the order, I find it easiest to jump around to whatever cams are suitable for measurement (i.e. lobes pointing up), then as they become measurable when the engine turns over. So to answer your question it does not matter the order as long as you keep track to hit all of them, and correctly identify/adjust intake vs. exhaust.

TnBob · #4 02-21-2011, 02:46 PM

The important thing is to make sure ALL the valves get adjusted properly.

Easy way is to draw a pic showing all 10 valves and mark them off as you do each one.

Biodiesel300TD · #5 02-21-2011, 02:51 PM

Order doesn't matter. I just progress through each on as I rotate the engine around. Which ever one comes up to the proper orientation next as I rotate is the one I adjust. I too also make a little cheat sheet with 10(or 8 for a 4 cylinder), and mark each box with and E for exhaust and I for intake matching the order on the engine, and mark them off as I go.

layback40 · #6 02-21-2011, 08:07 PM

Quote:

Originally Posted by TnBob

The important thing is to make sure ALL the valves get adjusted properly.

Easy way is to draw a pic showing all 10 valves and mark them off as you do each one.

I usually place a piece of card in the spring of each valve when its been done.
Its quicker and easier to just do them as the lobes come to the top. Less turns of the crank.

charmalu · #7 02-21-2011, 09:45 PM

I start at the front, and adjust each valve as the cam lobe points up.

Clean off the oil pipe with some brake clean, and write a "E" for exhaust and an "I" for intake at each spring with a felt tip marker. this way it helps me from confusing my self as to which one Iam on.

Or maybe a spot of red paint for exhaust, and blue for intake.

Also a good time to be looking at the timing chain as it comes around for broken/loose links.

Charlie

MarkM · #8 02-21-2011, 10:21 PM

I purchased a set of feeler leaf gauges for doing valve adjustments...two handles came with the set, all the leaf gauges came separate on a key change. On the handles, there is a little knurled finger nut for installing the desired feeler gauges. I set up both handles with desired gap for intake and exhaust, so I always have them. I put a piece of black electrical tape around the handle of the exhaust gauge and no tape on the intake gauge..this is consistent with schematic in the maintenance manual showing the intake and exhaust valves...intake = white arrow going in, exhaust = black arrow going out. This setup makes it easier to do the job, pick the correct gauge, etc. I also drew a diagram from the repair manual and made several copies of it...I use one each time I do the job...(of course I made these diagrams AFTER I did several valve adjustments using the book, and those pages of the book are a mess with black oil!)

Regards,

Mark

leathermang · #9 02-22-2011, 12:15 AM

Quote:

Originally Posted by charmalu

.....Or maybe a spot of red paint for exhaust, and blue for intake....

And then a dot of the same color on the correct feeler gauges ( both sides )..

Would be hard to mess up with those precautions taken.....

whunter · #10 02-22-2011, 02:16 AM

Quote:

Originally Posted by psaboic

My teenage son came up with a decent question I thought I would post to the forum. When doing a valve adjustment on a OM617, do you need to do them in a certain order (i.e. cylinder 5 then 4, 3, and so on) or can you do all the intake first then the exhaust (Provided of course the cam is set to the proper position for each valve before you do it?)

He said he thought if you were able to do all the intake first, then the exhaust you would minimize the chances of screwing up the adjustment. For the life of me, I cannot think of any reason why it could not be done this way.

Anyone??

Adjust each valve as the lobe reaches the position in the pictures in post #1 of the following thread.

Valve adjustment OM615, 616, 617 FYI.
http://www.peachparts.com/shopforum/showthread.php?t=107729

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