Lifter Noise

M

moparnum5

New Member
Jun 16, 2009
17
Pensacola FL
Boat Info
175BR
Engines
3.0l Mercruiser/ Alpha I
As my sig says, I have the little 3.0l Alpha 1 gen II combo. The motor has always had a little lifter noise, but I've had motors that clacked for years with no real ill effect.

So I was testing SS props the other day and I was trying a prop that had a lot less pitch then stock (17P vs. 21P) to see where my limits were with RPMs. I had the boat cruising at 4800rpm, which I understand is the safe upper limit for these motors, when the rpms started to drop for no apparent reason. I pulled the throttle back and sure enough the motor was knocking loudly. I putted straight back to the dock and pulled it out for the day.

I did a compression test and got consistent high results across all cylinders. (180ish which I thought was high, but it was consistent across them all)

The spark plugs were all in great shape, and all valves moved as they should.

Then only indication of trouble is a squishy lifter on the last valve. A blown lifter seems to be an odd problem; however it seems to be the issue. That being said, is there any easier way to change the lifter without removing the head?
 
Unless they have changed that engine there should be inspection covers on the side of the block, you should be able to remove and replace the lifters though that section. Just be sure that any parts removed are kept so they can be reassembled together. Your service manual should give you proper instructions for that.
 
Thanks for the quick reply!
I just went out and looked at it and that's what it looks like. My SELOC manual makes no mention of it or any process to remove the lifters. Hopefully it will be straight forward.
 
Pull valve cover, rocker arm, push rod, remove push rod cover(the side cover), remove bolt from lifter retainer, remove lifter, clean and inspect parts, lube all parts, reverse procedure. I hope the Seloc manual covers tightening the rocker arm, it should give you a torque for the rocker arm nut. You may have to get a lifter remover tool, not real expensive and you can get at local auto parts store. It is a pretty straight forward procedure, caution on the covers, don't jump on them with a pry bar, work them loose gently, if you bend or warp them you will have engine oil leaks.
 
So, I pulled the boat out of the garage so that I could play with the rocker while the engine was running, and to my surprise, that was most certainly not the problem. The clanking is coming from the front of the motor under the valve train. This leads me to believe that it is a rod bearing. To further fuel my diagnosis, there is no oiling for the first cylinder’s rockers, indicating something further down is out of place.

Well looks like I'm down for the season...can't afford this repair right now :(

Any ideas on a cheaper alternative to a full rebuild or reman long block without being a "patch" repair? I'd be doing all my own work other than machining.

Also, What would need to be changed to swap in a 4.3l?
 
Sounds like you wiped out a bearing. Gonna need to pull it, put on a stand, invert it, get the main/rod caps off and get a look at the bearings and journals. I'm not sure where the oil galleries are on that motor but you will defintiely need to tear it down and re-bearing it and clean out the galleries. I'd get the crank checked too by a machine shop for galling. You should be able to leave the pistons in the bores as long as the bores are clean. If' they're scored you need a complete rebuild. If not you need a bearing set and a gasket set. G/L.
 
yup, that's the plan right now. My biggest concern is what caused the bearing to let loose in the first place.
 
Are you sure of the 4800 RPM number? I have an old manual that shows 3900-4200 for the 120 hp version and 4200-4600 for the 130 hp version. And are you also sure of the tach's accuracy?
 
I had to go look in my manual after reading Frank's post, mine shows 3.0L 120 HP @ 4200 4600 and 3.0LX 135 HP @ 4400 4800. I had a 1987 that I thought was rated at 4800 max, that is why I checked.

From the latest diagnostics I have to agree that you may have a bearing bad. I also wonder about the lack of lube to the #1 rockers and the knock in the front of the engine, tried to find the lube chart for that engine to see what path it runs to get to the lifters. Possible oil galley plugged, main bearing spun. I will have to find my other book to get that info, at least I think it is in that book. Either way it does sound like you will have to pull and tear down to find out what the damage is. Just talking here trying to get my old brain to remember. Good luck to you and when you get ready to do the work let us know and someone will help you with advice.
 
hey guys, I finally have a chance to work on this thing. I was looking through my SELOC manual and it says I have to remove the whole stern drive in order to pull the motor. This seems like an aweful lot of extra work to get the engine out. Is there anyway to disconect the drive unit from inside the boat? Is the engine just coupled with a flywheel like an auto? It seems like if I can remove the dust cover on the tranny looking thing, then I could try to unbolt it from under the engine. I'm just not sure.
 
It's not a big deal to pull the drive. The shaft from the drive goes inside the engine coupler. You either have to pull the drive to free every thing up or if you have room in front of the engine you can move the foward when you free every thing up and then lift. On my old boat with a merc I just unbolted the drive and me and a friend wiggled it loose, and took it off, I used an engine hoist on my omc but it was lite enough for me to lift it by my self.
 
I would pull the drive then the engine, that what when you reinstall the engine you will be able to align the engine before you put the drive back on. When you pull the engine you always need to check the alignment if you don't then you can get things in a bind, may not even be able to put the drive back on and if you should pull the engine with the drive still mounted and in stalled it back and it is not lined up then you have to pull engine again to get the drive free so you can remove it and align the engine. You should be able to do all the work yourself, you will need to borrow or rent an alignment shaft, if you can't then you may have to take the boat to someone and just have them do the alignment.
 
Thanks for the help. I was able to pull the drive and get most everything unhooked from the engine. I'll get some pics later.
 
UPDATE:


I've got the engine out of the boat and the engine mostly stripped down.

How do you remove the harmonic balancer? Usually there is a bolt holding it in, then you use a puller. I see no main bolt, just the threaded holes for the puller :huh:
IMG_2126.jpg
 
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That dampner needs to be pulled with an automotive type Harmonic Ballancer Puller. Yes there is typically a crank bolt holding it on and that is how it would be install too. Seems odd that the end of the crank is painted over as if this engine has been worked over in the past. What I do when I suspect internal engine failure is cut open the oil filter and inspect for debris. It dosn't soung good. ...Ron
 
It looks like there may be a bolt broke off in the hole in the center of the crank, I can't imagine that bolt breaking off as it is a rather large bolt. There should be threads in that hole for a bolt to screw into. You should be able to pull the ballancer off with a steering wheel/ballancer puller.
 
There is no broken bolt that I can see, or anything threaded in the center. I just don't want to put a puller on it without knowing how it is attached.


So I removed the pistons today. The #1 piston and cylinder is all sorts of scarred up on one side. The wrist pin is really tight and blued like it was extremely hot. I used some plastigauge on the rod bearing and it was to spec. My best guess right now is a plugged oil galley that led to a frozen wrist pin....but still not sure. I'll check the main bearing clearances tomorrow, and hopefully get that harmonic balancer off.
 
well, it's been a while and everything is still apart. I started flight school eearlier then expected and haven't had time to mess with this.
That being said, I don't have time to rebuild this thing anymore and need to start looking at faster options. Ideally, I would like to have a quality long block to throw back in...whether it is the same motor rebuilt by someone else or purchased elsewhere.

What do you think and where should I go? I'm in pensacola/milton Florida.
 
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