Re: 'Stuck' Mercruiser 170 will not turn
Okay, ready for the big, BIG news?!!!!!!!!!!!!!!
The head is off. And the good, GOOD news is that things look pretty good. The #4 piston was virtually (if not actually) at TDC, so that prevented any rusting of the cylinder wall by virtue of water / moisture on top of the piston. I'll have to take a peek at the timing mark to see if I'm actually at TDC, or, if not, which side of TDC I'm on. Because I anticipate maybe tapping on a piece of 2x4 resting on top of this piston, or maybe I'll get crazy and cut a circular piece of 3/4" plywood to fit on top of the piston to protect it, then use the 2x4 on top of that, and tap on it that way to force the piston back down -- while maybe having a helper try to turn the crankshaft (perhaps from the rear using the driveshaft?). So it'd be nice to know which side of TDC I'm on so that I can have the helper trying to turn the crank in the proper direction.
Then again, maybe I should do my tapping on one of the other pistons? But aren't they at BDC if this one (and #1) are at TDC?
So TDC could be good news and bad news, I suppose. Good news for the reason I stated, and also as per below, but bad news because it doesn't give me a good "bite" for forcing this (or another) piston downward and thus freeing up the stuck piston.
Anybody who has a suggestion on how to free this piston up (short of pulling the engine) please chime in.
As I say, the piston was high enough that any possible cylinder wall corrosion above it could really only be to the ridge that ya have to ream before removing the piston (or maybe just a hair shy of that) and that area obviously never gets involved in any ring-sealing situation. So corrosion there is no big deal (and there isn't any anyway). I can't imagine that there's going to be any cylinder wall corrosion below the top of the piston. This was not a case of the cylinder head gasket leaking -- this was due to the fact that the boat hasn't been run in too many years and thus moisture, and maybe even some water, has gotten to that back cylinder because the boat is stored on the trailer and tilted back to let the rain water run off the cover.
The other cylinders all look fine. Boy, are these pistons BIG!
The intake valve looks like I should pull it and check it out. No problem there.
I'll likely also pull the harmonic balancer just to make sure I'm okay there. Thanks again for that one, Mdlee. Might also pull the starter, just to be on the safe side there too.
The job went smoothly. Consistent with my ever-adaptable personality (a.k.a shapeshifter) I reversed myself on the issue of not removing the exhaust and intake manifolds -- and I'm glad I did.
Here's how that came about. I mentioned previously that I thought I might destroy that power steering pump stud that needed to be removed (because I was going to use my pipe wrench to get it out). But then I remembered the old "double nut trick" and so I tried it and damn if it didn't work like a charm. So that stud came out pretty slick.
The main reason I was going to leave the exhaust manifold on the head was due to the long studs that would have prevented me from simply unbolting the manifold and pulling it away from the head a bit so that I could just lift the head up and out. In order to do that I'd have to remove those long studs, and I figured (from past experience) that would be a real PITA. Those stud threads are usually stuck pretty good.
But after my stunning success with the double nut trick on the power steering pump stud, I decided to try that trick with the long studs on the exhaust manifold. There are only 3 of 'em and the first two actually came out by just turning the original nut -- the coarser 'stud threads' actually preferred to give way to the finer 'nut threads' on the other end of the stud (they were a bit rusty, I have to say). So just trying to 'unscrew the nut' caused the stud to unscrew.
That was a bonus fer sure.
The other one came out easily with the double nut trick.
The other reason I changed my mind (assuming I could get those long studs out) is that there's a LOT of hoses and stuff to disconnect if ya wanna take the exhaust manifold off. Leaving it in place on the boat means ya only have to take one very short hose off -- from the head to the (very heavy) cast iron coolant reservoir. That hose is so short that it's kind of a PITA, but it wasn't a big deal to get it off.
The intake manifold is a breeze to take off, so no problem with removing that.
So it looks like Service Manual #8 was right on the money (Don?) because removing the manifolds is DEFINITELY the way to go -- assuming you can get those 3 long studs out.
I was pleasantly surprised when I pulled the rocker arm cover off. The rocker arms look brand new and everything under there is spanking clean. It could be a new or rebuilt head but the rocker arms do indeed look new to me. I had a feeling this engine was worked on fairly recently before I got it.
So that's my story so far, and I'm sticking to it.
Now the first thing I have to do is get to the store for some more GOOP because I'm out of it. I believe I actually have another unopened container of it around this zoo somewhere but I'm giving up trying to find it. I'll just go buy another one -- THEN I'll surely find it. Cuz that's how that ALWAYS works.
Anyone not familiar, here ya go -
http://www.goophandcleaner.com/
This is the ONLY stuff you EVER want to use (good for stains when doing laundry too -- as they like to point out). I've been a shade-tree mechanic since I was 13 (50 years and 2 wives ago) and also worked as a mechanic in several garages during my teen years. Then I was an Army-trained track and wheeled-vehicle mechanic at Uncle Sam's urging back in the day (they actually gave me an MOS that I was highly qualified for -- go figure) so I know a thing or two about hand cleaners. And trust me, this is the ONLY stuff you'll ever need. It's a freakin' miracle -- the Eighth Wonder!! A lot of supermarkets carry it around here, so it's easy to get.
They gotta be making MILLIONS off this stuff.
As to Uncle Sam and that whole thing, it was 1966 and those of you old enough to know might remember what was goin' on back then. I guess I should have been reading the papers more carefully, or otherwise paying more attention, because I never expected that I couldn't take a year off after high school before starting college. Well, suffice to say, I got my letter even before my 19th b'day -- and ya only had to register when you turned 18.
There was no "lottery" back then.
Look, I was 18 freakin' years old. My attentions were diverted elsewhere. Who was reading the freakin' papers? I had better things to do.
Have ya ever seen
Scent of a Woman? Hoo ha!
Anyway, when they gave us the battery of tests at Fort Dix, most of the goofballs I was with were just goofing around about it. Bad idea -- real bad idea. If you had some sort of talent for something they ALSO might need, well then you maybe had a shot at not getting the dreaded "foot soldier" MOS. So I took those tests REAL SERIOUS-like.
And son-of-a-gun if they didn't make me a mechanic.
Spent my time in Germany drinking that good German beer and hanging with the Fr?uleins. The Man In The Black Pajamas never got past Heidelberg (as old Lonesome George used to sorta say).
Oh yea!!!
Being the genius that I am (if I do say so myself -- and I do) they also wanted me to go to OCS. But I figured they had enough raw 2nd lieutenants to send "in country" for cannon fodder, so I declined that offer.
Too bad it wasn't peacetime because being an officer in this man's peacetime Army could definitely have been fun -- I'd have even gladly taken the extra year.
Anyway, the head's off and things are looking good. Suggestions on what to do next welcome, as always.
.
