Engine stuck

[babikov]

Hi,

I have a 4.3 LX/V6 Alpha One Balanced Shaft/Thunderbolt IV Ignition engine on my 20? Sea Ray. The year is 1993. The engine is in very good general condition, with only 600 hours on it, after 20 years of light use.
It worked fine for me for 5 years, but now I got a serious problem.

When I tried to start the engine last time, I heard a strong single knock sound, like if someone would hit a rail with a hammer. Starter tried to turn the engine, clearly, but could not. It was stuck. The oil was OK, good quality and in good amount. I took my boat to a small mechanic shop at the lake. They checked battery and the starter ? OK. They were also able to turn the engine (by hands, I guess, not sure) but said that it feels like something inside the engine is loose. They mentioned it could be due to starting gears, or the timing chain/gears. They could not do this job at that shop in the time frame while I was on vacation, so, they did nothing.

I can manage to do the seasonal maintenance by myself, but this problem seems to be more severe, and I will probably have to take this engine to an experienced mechanic, finally. I would appreciate, however, if someone could give his opinion about what might be the problem. Knowing roughly what it could be, and what it could not, will help me to choose the right shop, and the right guy to take care of the engine.

What might cause the problem, is that the engine was dieseling sometimes (continuing several turns after the ignition key was turned off). I thought this was fine, not a real problem. But now I feel that some of those detonations were hard enough to break something inside. The serious problem described above happened when I tried to start the engine after it was dieseling during the preceding switch off.

I would greatly appreciate to read your hypotheses.
Thanks!

 

[achris]

Re: Engine stuck

What can happen while the engine is 'dieseling' is it can suck water back though the exhaust system and into the cylinders. I would remove the spark plugs and try and spin the engine over with them out. Watch for water coming out of any of the holes.

If you have a serious problem, and are looking for a shop, look for one that has Mercruiser Certified Technicians.

Chris....

 

[babikov]

Re: Engine stuck

Thanks, Chris.

Any other thoughts? Anyone?

 

[Bondo]

Re: Engine stuck

Thanks, Chris.

Any other thoughts? Anyone?

What might cause the problem, is that the engine was dieseling sometimes (continuing several turns after the ignition key was turned off). I thought this was fine, not a real problem.

Ayuh,.... It IS a Serious problem, that causes hydro-lock, which is what ya just went through,...

Unless yer gonna turn yer own wrenches, ya need a Mechanic to fix it up,...

Generally speakin' dieselin' can be cured by a Tune Up, 'n operator education,...
aka; let it idle after hard runnin', 'n give it a proper Tune up,...

 

[babikov]

Re: Engine stuck

Yes, I saw that ideling, after a fast run and just before switching off, does really helps. And I tried to do it, in almost all cases but few, when I was disturbed and forgot, etc. As for Tune up, I took it to a mechanic for tune up. In the shop it looked like it helped, but later the problem of hard starting and dieseling during switch off returned.

Well, will try to take spark plugs out, as Chris suggested, and repost after that. Thanks.

 

[babikov]

Re: Engine stuck

OK, took a wrench and pulled the spark plugs out. And what – a lot of water in cylinders!

Couple things to note: 1) How amazingly sharp this blog is. 2) How amazingly stupid was that mechanic on the lake (see my description above). I gave him the same symptoms – dieseling and stuck – and he had no idea about possibility of a hydro-lock! What a …

Anyway, I sprayed some fogging oil into cylinders, let it sit for a while, and turned the key on. The engine rotated without any trouble, a lot of water ejected. Cleaned the mess. Sprayed more oil into cylinders, let it sit, turned the key. Cleaned the mess. Sprayed fogging oil third time. Let it sit till tomorrow.

Now, what is the best way to proceed tomorrow? My plan was to turn the engine one more time tomorrow without plugs to push the oil out. Put in new plugs. Take it to the water (or muffs?) and try to start. Is there anything special I should do for this condition? Should I change the motor oil immediately, or it can wait for a month till winterizing? Anything else?

I was thinking replacing the plugs, just in case (there was water). They don’t look bad, but I would better spend $5 on new ones. The old plugs look unusual to me – they don’t have a copper ring, but have a cone-surface. Is this the right plug? Are they all like this in the boats? Is it because they are expected to be puled out seasonally for fogging? If I buy new plugs in Autozone, what gap should I pick? Or this is a special boat plug?

Thanks for your suggestions!

 

[achris]

Re: Engine stuck

IF the engine is 1993, then the right plug is NGK BR6FS or AC MR43T. Please post your engines' serial number to confirm the right plugs. And yes, they have a tapered seat, and no gasket. And any auto shop should be able to supply the plugs. What plugs did you pull out?

As for oil... It's quite possible (in fact, I would say likely) some water has seeped passed the rings and found it's way into the oil pan. Personally, to avoid any risk of mixing that water and oil together (and then distributing it right through all the engine galleys :facepalm, I would drop the oil from the pan via the plug on the pan (not sucking it up through the dipstick) and put new oil straight in.

Once you have new oil, I would run it on muffs and monitor the condition of the oil. Let the engine fully warm up, then do a compression test....

Chris..........

 

[babikov]

Re: Engine stuck

Thanks, Chris.

The engine is 1993 4.3LX/V6 Alpha One Thunderbolt Ignition, serial number OF0244564. The transom is OF058634. The drive is OD886515.

The old plugs: CHAMPION RV15YC4. On the metal part: 203 7E.

Thanks.

 

[achris]

Re: Engine stuck

Thanks, Chris.

The engine is 1993 4.3LX/V6 Alpha One Thunderbolt Ignition, serial number OF0244564. The transom is OF058634. The drive is OD886515.

The old plugs: CHAMPION RV15YC4. On the metal part: 203 7E.

Thanks.

There's one too many numbers in the engine serial number (I think it should be 0F024564)... But it's in the Gen II range (for the engine, not drive. But the drive is also Gen II :facepalm: I know that's confusing) so the right plugs ARE the NGK or AC numbers I listed. I would 'deep-six' those champions ASAP... (only THE worst spark plug for multi-cylinder engines EVER produced)....

Chris......

To clarify the engine/drive thing....

The first of the balance shaft V6 engines was called a 'Gen II' engine (1992 to mid-1996). The next 'update' was for the vortec heads, and that was called a 'Gen+' engine (mid-1996 to current).

For the drives, the Alpha One ran from 1986 to 1990. The next update was then called 'Alpha One, Gen II'.... and that is still current, and what you have...

Hope that helps...

 

[babikov]

Re: Engine stuck

Thanks, again, Chris. You are correct, this is Gen II. I checked the web site of O'Reilly and it looks like they may have the NGK. Should I also provide the gap size when I buy them, or there is only one gap value for boat motors?

 

[achris]

Re: Engine stuck

I ALWAYS check the gap on any spark plug I install. Just a habit from the old days. Supplied from the manufacturer spark plugs are usually only a non-specific gap. If the gap is specific, it's usually reflected in the number, like BP8H-N-10 (will be 1mm).

But the yours will not be the right gap from the box. The correct gap for these plugs on your engine is 0.040"...

Chris.....

This is the right one....

http://www.oreillyauto.com/site/c/detail/NGK1/4323.oap?ck=Search_br6fs_-1_-1&keyword=br6fs

 

[babikov]

Re: Engine stuck

Got the plugs, gaped them to 0.040". How tight these tapered plugs should be screwed in? The plugs on my car of similar size, but with gaskets, need 12 ft. lb. Is it the same on the tapered plugs? Thanks.

 

[achris]

Re: Engine stuck

I've never used a torque wrench on spark plugs... I usually just 'nip 'em up'.. I looked up the correct torque setting for you (and my own curiosity)... 15 ft.lb.... So yeah, about the same as gasketed plugs (just a tweak more )....

Chris......

 

[babikov]

Re: Engine stuck

Thanks, Chris. By the way, I checked the oil drain. Removed the plug and found ... some water in the oil, just as you suspected. Interestingly, the water was well separated from the oil, not really mixed in. And there was not much, may be 1-2 mililiters. The oil on top of it was not milky, very dark but transparent, typical to the end of season. I drained all oil, purchased new, will buy oil filter tomorrow and start putting things back... Thanks for your guidence!

 

[babikov]

Re: Engine stuck

OK, put new oil, new filter. Cranked the engine without spark plugs one more time, to push out the rest of fogging oil and water. Put new spark plugs in (forgot to use the unti-seize compound, was rushing, hope this is OK). Connected wires. Put muffs on and tried to start. Lots of smog, from fogging oil I guess (I sprayed it directly into cylinders, see above). And, after three or four cranks, the engine started!!!
Runs nice and smooth. May be this is just me, but I feel it works even better now than before, must be due to new spark plugs, correctly gaped.

Waited till engine heats up, and tried to increase RPMS to about 15000. Kept there for a minute or so – no problem. Let the engine idle for few minutes, switched off nicely, no dieseling.

Unbelievable, but I did it myself, with the guidance of iBoats experts, of course, particularly Chris.

Tomorrow will check the oil again, may be drain some of it (at the bottom of the drain tank) out to monitor. Will change the entire oil in a month or so, anyway, to winterize.

Tomorrow will take the boat to the lake and will try to run it at progressively higher RPMs. Any tips on that?
I will take a friend with me who claims he knows how to adjust ignition, to avoid dieseling in the future. Is there a video or an understandable description of how to adjust ignition? You may think I try to do too much by myself, better take the boat to good mechanic now. Well, may be. I try to do things by myself not only to save $$, but also because I saw so many bad mechanics. So, adjusting ignition, in order to avoid dieseling, is it doable by a non-expert like me? Thanks for your opinion.

 

[achris]

Re: Engine stuck

..... Tomorrow will take the boat to the lake and will try to run it at progressively higher RPMs. Any tips on that?
I will take a friend with me who claims he knows how to adjust ignition, to avoid dieseling in the future. Is there a video or an understandable description of how to adjust ignition? You may think I try to do too much by myself, better take the boat to good mechanic now. Well, may be. I try to do things by myself not only to save $$, but also because I saw so many bad mechanics. So, adjusting ignition, in order to avoid dieseling, is it doable by a non-expert like me? Thanks for your opinion.

Now I'm sacred.... If he has only experience with car engines, and not the special circumstances that apply to marine engine....

The ignition timing is not what causes dieseling. Please, DO NOT let him mess with the timing... The timing on those engines is set at 8BTDC at idle (650rpm), and should not be moved from that.... Check it by all means, if it's out, adjust it back to 8BTDC....

Dieseling is caused by hot carbon deposits in the combustion chamber firing the fuel after the ignition is shut off. If the engine continues to diesel after shutting off the ignition, you could REMOVE the distributor from the engine completely, the dieseling will not stop....

The best 2 pieces of advice for dieseling... 1. Make sure the idle speed is set as low as practically possible (that lets less fuel into the chamber with the throttle closed). Make sure th4e throttle cable is adjusted correctly and not holding the throttle open slightly.... 2. Let the engine cool a little before shutting down....

Good luck....

 

[babikov]

Re: Engine stuck

Got it, Chris. Thanks.

 

[babikov]

Re: Engine stuck

New day, new problem, and new question from me:

Checked the motor oil (in the drain pan) in the morning and found that it is milky, light brown color. I never seen such bad oil in the engine before. Apparently, some water remained somewhere in the engine, either in cylinders or internally, and mixed with new oil as I hard-started and light-run the engine yesterday.

The only solution I see is to drain the oil again, and may be again, to “flush” the engine this way. My concern is that Quicksilver Synthetic Blend is pricy, and this “flushing” will be expensive.

My question is this: Can I use regular cheap car oil for these flushes, and what kind? Say pour cheap oil, run for 10-20 min, drain, repeat until the oil is clean. The gallon of cheap oil is about $5, doing 4-5 of these flushes is OK with me. Even if the oil is cheap, it should be OK for 10 min, correct? What do you think?

Should I also change the filter every time? Or just remove it, shake out old oil and put back?

Of course, at the end I will place new high quality oil and filter.

Thanks for your consideration.

 

[Bt Doctur]

Re: Engine stuck

You will never remove it just by changing oil. the motor need to be run at operating temperature to get rid of the remaining moisture.
15w-40 or 20w-50 will work.

 

[babikov]

Re: Engine stuck

Thanks, Bt Doctus.

How would you recommend running it, at idle (muffs), at somewhat elevated RPMs (muffs), or at the lake at a good speed? And for how
long before the next change?

And, are there any special chemicals to put in the motor oil (to bind water) during these cycles of “flushes” + operation?

Thanks a lot.