mercruiser 3.0lx cylinder head help!!!

SVFreddy

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Oct 30, 2012
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I am replacing a head gasket in this merc 3.0 and have ran into a bit of a problem and would like some help/suggestions.
While trying to torque the rocker arm nuts, my torque wrench failed to work properly to the suggested (manual says 20 ft pounds) specs. I should have known better but in the process over tightened the nuts on two of the rocker arm studs, then when I realized it and backed them out, The rocker arm studs started to back out with the nuts. as you can see in the pics, The two are slightly higher than they should be.
Where do I go from here? Whats the best cost effective way to resolve this?
I also read on the forum that the manual isnt exactly clear on the right steps to re-installing the rocker arms?
Somewhere on here I read that you should find compression tdc and tighten the nuts so that the play is token out of the push rods? Anyone else agree with this? any help will help, Thanks

engine type:
mercruiser 3.0lx 1997
s/n 0k03XXXX
20130505_193308.jpg
 

slag

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Re: mercruiser 3.0lx cylinder head help!!!

Disregard, they are press in, not screw in.
 

SVFreddy

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Re: mercruiser 3.0lx cylinder head help!!!

I thought they were pressed in studs so how would they screw back in? even if they did screw back down, Would they stay down?
 

Don S

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Re: mercruiser 3.0lx cylinder head help!!!

While trying to torque the rocker arm nuts, my torque wrench failed to work properly to the suggested (manual says 20 ft pounds) specs.
What manual are you using?????? I know of no 3.0L engines that get the rocker arms torqued down to 20 ft lbs.

engine type:
mercruiser 3.0lx 1997
s/n 0k03XXXX

What is the full serial number, XXXX means nothing.
 
Joined
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Re: mercruiser 3.0lx cylinder head help!!!

It looks like you have the nut on backwards, the taper end usually goes to the rocker!!
 

SVFreddy

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Re: mercruiser 3.0lx cylinder head help!!!

service manual 26. Sorry picture of the serial number is blurry, im away from home to double check but from a picture it looks like 0k038470
 

Fishermark

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Re: mercruiser 3.0lx cylinder head help!!!

It looks like you have the nut on backwards, the taper end usually goes to the rocker!!

No, there is cone shaped bushing under the nut. He does have the nut on correctly.

If your studs are pressed in, your only option may be to take it to a shop and either have a new stud pressed in, or tap it and install screw in studs.
 

Don S

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Re: mercruiser 3.0lx cylinder head help!!!

It looks like you have the nut on backwards, the taper end usually goes to the rocker!!

Those are right, the taper does go up. The nut sits flat on the round "Ball Unit"
 

RogersJetboat454

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Re: mercruiser 3.0lx cylinder head help!!!

Most likely press ins....

I would like the opinion of a machinist on this one to see if they can be pressed back into place, or of they need attention. Did you bring the head to a machine shop for work after what I would assume was a blown head gasket?
 

81 Checkmate

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Re: mercruiser 3.0lx cylinder head help!!!

I guess my eye is bad....... Per Don's specs
 

SVFreddy

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Re: mercruiser 3.0lx cylinder head help!!!

Most likely press ins....

I would like the opinion of a machinist on this one to see if they can be pressed back into place, or of they need attention. Did you bring the head to a machine shop for work after what I would assume was a blown head gasket?
Blown head gasket is correct, I inspected the block and head and everything seemed normal so I just went ahead and installed a new head gasket. From what I keep hearing, They're pressed in which would probably be the reason they sell oversized replacment studs.
 

Don S

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Re: mercruiser 3.0lx cylinder head help!!!

service manual 26. Sorry picture of the serial number is blurry, im away from home to double check but from a picture it looks like 0k038470

Just looked at 26 (wrong manual for you BTW) and it looks like Merc added pages 3A-24 and 3A-25 by mistake. If you look at earlier pages 3A-17 to 19 you will see the proper way to adjust the valves.

Still the wrong SN, that is for a V8.
 

Don S

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Re: mercruiser 3.0lx cylinder head help!!!

Here is a page from the proper manual (#13) what is strange, is they also showed the wrong specs, but they at least noticed it.

Click on the little box in the middle of the page.

View attachment #13 GM 4 cyl 90-97 101.pdf
 

Fishermark

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Re: mercruiser 3.0lx cylinder head help!!!

Here is a page from the proper manual (#13) what is strange, is they also showed the wrong specs, but they at least noticed it.

Click on the little box in the middle of the page.

View attachment 192969

That's curious they would do that - I wouldn't have thought of clicking on that little box unless you mentioned it. Do you see that often in the online versions? (Not mistakes necessarily, but the little info box).
 

Don S

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Re: mercruiser 3.0lx cylinder head help!!!

That's curious they would do that - I wouldn't have thought of clicking on that little box unless you mentioned it. Do you see that often in the online versions? (Not mistakes necessarily, but the little info box).

That is the first one I have seen from Merc, I have added notes to a couple in the past. I just changed my copy to reflect the error.
It now looks like this. From manual 26

View attachment #26 3.0 98-newer 127.pdf

Also, if I give a link to this manual now, it will also reflect the change.
 

RogersJetboat454

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Re: mercruiser 3.0lx cylinder head help!!!

I inspected the block and head and everything seemed normal so I just went ahead and installed a new head gasket.

I assume this inspection included using a machinist strait edge and feeler gauges to check the trueness of the head, and deck surface, right? ;)
 

SVFreddy

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Re: mercruiser 3.0lx cylinder head help!!!

Brought the head to a machinist and got new ones pressed in, Also found a sucked in valve and got that fixed too. Kind of a good thing I brought it in.
Also found the right way to adjust the rocker arms per the "right" manual. Just waiting on the gasket to come in from iboats ;)
Thanks again for all the help guys!
 
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