Adjusting Valves on a Mercruiser 3.0lx

[MikeDobbs]

Engine Serial # 0K277779

I'm having some difficulty getting the valves adjusted properly and have read two different suggestions for the correct method. I cannot find the correct manual for this engine- so if anyone has the link I'd very much appreciate it. Otherwise, if anyone has the manual I'd love to know how I am supposed to do this.

Method 1: You simply bring each cylinder to TDC compression stroke and torque the nuts to 20lbft of torque. This sets the last automatically.

Method 2: You bring cyl 1 to TDC compression and adjust certain valves by loosing nut until you can spin the rod between your fingers. Then, slowly tighten until you cannot spin the rod anymore. This is zero lash, and from here you tighten 3/4 of a turn.

I tried method 2 (being the first one I came across) and it seemed to go fine, but I had a fair amount of what sounded like valve train noise. So I tried it again, and now I can't even start the engine. Then I came across the second (err. 1st?) method and it sounds a lot simpler, so I'd like to give that a try tomorrow if it is correct.

Thanks in advance for any help- this has been a particularly frustrating day of working on the engine...

Video attached if you care to have a listen and suggest what you think the problem might be- or what I should do to diagnose.

 

[flipbro]

You DO NOT tighten till you can't spin the push rod. Just spin it till you feal the slightest resistant thats zero lash then turn half turn. If you tightened till they wouldnt turn then three quarters more I can understand why you have so much noise and troubles starting.

 

[airshot]

According to my mercruiser service manual (3.0) it states to adjust until you remove end play...ability to move push rod up and down, not just spin...then turn additional 3/4 turn. From the sound of your video....sure you don't have a collapsed lifter? Either that or they are way out of adjustment.....Are you sure you were at tdc and not 360 out. It takes two full revolutions to make tdc. I would check lifters and valve springs then start over.

 

[Bt Doctur]

listed as a `97, both manuals have 3/4 turn down from 0 lash MERCRUISER WOPS-TWOPCEX-WO REM-EST IGN 3.0LX ALPHA
PARTS CATALOGS

• 809870 96 - 3.0L/LX Alpha One

 

[MikeDobbs]

From the sound of your video....sure you don't have a collapsed lifter?

No- how can I tell if I do?

Are you sure you were at tdc and not 360 out. It takes two full revolutions to make tdc.

Yes- that I'm sure of- rotated until both valves remained still as timing mark approached the 0 mark. Adjusted 1 IE, 2I, 3E, 4I. Then 360 to get #4 TDC, and adjusted the rest. Sounds like I'm being too aggressive with finding the zero lash position. I'll try this morning with a softer touch- perhaps that will do the trick.

I would very much appreciate any advice on diagnosing/replacing a lifter.

 

[MikeDobbs]

You DO NOT tighten till you can't spin the push rod. Just spin it till you feal the slightest resistant thats zero lash then turn half turn. If you tightened till they wouldnt turn then three quarters more I can understand why you have so much noise and troubles starting.

This may be my problem filipbro- thanks very much. I'll readjust this morning following your advice

 

[Silvertip]

And make sure the engine is turned so the lifter is on the base circle of the cam. Follow the manual. You cannot adjust all the valves without turning the engine.

 

[MikeDobbs]

And make sure the engine is turned so the lifter is on the base circle of the cam. Follow the manual. You cannot adjust all the valves without turning the engine.

Yes- that much I know- I have to adjust 5 of the 8 at #1TDC firing, and the other 3 at #4 TDC firing (360 degrees apart)

So I went out this morning, pulled all the plugs, and very carefully adjusted the valves to just take out any vertical movement, so they still spun rather easily, but with not "play" in the vertical direction. Also inspected all push rods against a piece of glass- all straight.

After this valve adjustment she started right up. I've turned the engine off and started it back up a couple times now, so we seem to be back to a reasonable adjustment now. Still have a noise- still unsure what to do. flipbro mentioned that he thinks there's a cover on the side of the block that reveals the lifters for inspection/removal. Can anyone verify this? If so, is it as simple as pulling the old one out and putting the new one in? I can't find anything online about lifters in a merc 3.0

Also- what do you guys think about running it around on the water with some seafoam or similar product at a low speed? Might that be worth a try, or do you think it may do more damage than good?

Thanks as always!

Here's an updated video of the engine after most recent valve adjustment:

 

[flipbro]

Goggle Changing Lifters in a 3.0 mercruiser you tube. Watch some of the videos alot of your questions will be answered

 

[MikeDobbs]

Hey flipbro- I googled that (and many other search phrases) but aside from another thread here on iboats I haven't found anything describing or showing the process. I have been able to confirm the side plate you mentioned- although I'm not 100% sure I can change the lifters by simply pulling that.

If anyone on iBoats can offer me some guidance about how to change the lifters on my Merc 3.0lx I'd very much appreciate it.

 

[Bt Doctur]

remove the pushrods, remove the side plate,lifters lift up and out

 

[airshot]

The side plate is used for lifter replacement, however the valve adjuster must be backed off and the push rod lifted to get the lifter out. Sometimes they can stick in the hole due to all the oil in there. They can be slippery little buggers to remove. Lifters can appear to be good but break down under pressure. On occasion some gunk might be built up inside preventing proper oil pressure inside. In the old days we would take them apart and clean them to try and get them working again. Sometimes it worked and sometimes it didn't. I don't believe lifters are that expensive though.

 

[flipbro]

Mike that side plate is how you change service that part of the valve train. Did you watch the youtube video on how to tell if you have a bad lifter?

 

[MikeDobbs]

Mike that side plate is how you change service that part of the valve train. Did you watch the youtube video on how to tell if you have a bad lifter?

No- I'm not sure of which video you are referring to. I will search for it now- if you have the link, and can post it, I'd appreciate it.

Also thinking, perhaps doing an oil change with a quart of Rislene or Mystery Oil might not be a bad idea? Thoughts?

BtDoctur/airshot- is there anything I need to do when replacing the lifters? I've seen a video online where they said to soak the lifters in oil overnight- is that necessary? The service manual (#13) is pretty vague on the procedure. It doesn't even mention that plate until the end where it says to put it back on (even though it never said to take it off

I'm happy to replace the lifters- they're only about $8 apiece. If there's a way to verify that they're causing the problem before hand that would be great though- otherwise it's $100 bucks and an afternoon still chasing a problem...

 

[MikeDobbs]

Hey everyone- I ordered the lifters, but I realize I will need a lifter cover replacement gasket. I can't find the correct part #- it is conspicuously absent from the parts manual. Does anyone know the correct part number for the gasket? I think it is either:
Sierra 18-0328-9, or
Sierra 18-2815

My engine serial # is 0K277779

Thanks

 

[MikeDobbs]

Pretty sure I got it- [h=1]Sierra 18-2815 Push Rod Cover Gasket[/h]
If anyone knows that to be false please let me know : )

Otherwise, if you're looking that should be the one