Help me trouble shoot my engine!

centerline · Jun 12, 2012

excessive blow by is an indicator of a well used engine, but that doest mean it needs a rebuild..... with what you are discribing I would check the condition of the fuel itself.... is it cloudy or clear? it needs to be clear...greenish, redish, yellowish tints are ok, but clear..... if its cloudy it has absorbed water and diesel can hold a lot of water. the more water molecules that has adhered to the diesel molecules, the less readily it combusts. it can cause a vibration and at low rpms in a worn engine there wont be enough compression to keep it running properly. and it will vibrate due to the way a diesel is timed and the late incomplete combustion......
good clean fuel should burn fine without any symptoms....
another issue that can duplicate your symptoms is worn injectors..... it works the same way. the fuel is delivered in an incorrect pattern at a lower rpm and causes erratic combustion of the fuel, which in turn, causes black stuff on the water and vibrations. at higher rpms, there is more and quicker compression in the cylinders so the fuel will burn better and is less noticable.... but it still doesnt burn like it should.
either way, it sounds like you are getting fuel as it seems to run fine at the higher rpms, so i would check something other than fuel delivery at this point.

anchorclanker · Jun 12, 2012

weinie said:
I think you confirmed it for me

... or is my thinking overly fatalistic?

IMHO, cleaning injectors is part off regular maintenance, especially when you have a running problem. For all we know a good tuneup is all the poor thing needs.... A check/reset of injection timing, a couple oil changes, clean injectors, cleaning out the cooling system, and running it hard for 10 or 20 hours might solve all your troubles. And as stated, making sure the fuel is good quality. Any one of those could have caused your trouble, but the blow by is now a mechanical problem.

Ive had many diesels that initially had some blow by and/or smoked, used oil, ran like crap, that came back and ran like a champ with some solid TLC and a long hard run. Diesels dont like to sit around dormant, and then putt around idling intermittently. These engines are designed to run over 10,000 hours, possibly three times that, but many barely see 1000 hours over a 30 year span and die of neglect rather than wear.

newboatowner · Jun 19, 2012

I had a bear of a time with my M18 that is in my Catalina 30. It started stallling at low RPMs and smoking at speed and finally, at the end of last season the engine would not start after I installed a new starter motor. After rewiring the harness, checking all ground wires, replacing the injectors, changing the filters, blowing out all lines, fully charging the batteries and hitting it with a hammer, I removed the injector pump and sent it for a rebuild. I replaced it and, voila, the engine starts immediately and runs very smoothly. The only problem is that it is so severely underpowered for the boat that I grow old getting out of the marina.
The injector pump can be expensive but this rebuild by Hanson Marine was reasonably priced.

Stu Jackson · Jul 27, 2012

I'd buy two new gaskets. Th old one will be wet and could disintegrate when you remove it. And the edge of the gasket is very close to one of the mounting stud holes and requires careful fitting it back on, so if you miss and tear the gasket it'll be useless and you'll need the second one. They're not expensive.

anchorclanker · Jul 27, 2012

You need to pull the injectors and clean and test them, and follow through with a thorough servicing and tune up. Check valve clearance, injection timing, adjust no load rpm, check aircleaner, exhaust elbow, etc... Then go out and run it hard, 90% for a few hours. You can check rough compression after you have injectors out if you want, but it probably wouldnt start if it was under 300, and if you have that much there is some hope to turn it back around. If one is near dead, well, thats that isnt it?

If it were me, I would put an ounce of MMO in each cylinder while the injectors are out. If it has carboned up rings it would help free them up. Just be sure you spin it over on the starter before putting the injectors back in to blow the oil out. It will probably destroy the motor if you dont.

Stu Jackson · Jul 28, 2012

http://c34.org/bbs/index.php/topic,978.0.html

Stu Jackson · Jul 31, 2012

weinie said:
If anyone needs the parts list, please PM me and I gladly send it to you or if anyone has a website to post it on, that would also be great.

Why not right here?

jrowan · Aug 3, 2012

anchorclanker said:
You need to pull the injectors and clean and test them, and follow through with a thorough servicing and tune up. Check valve clearance, injection timing, adjust no load rpm, check aircleaner, exhaust elbow, etc... Then go out and run it hard, 90% for a few hours. You can check rough compression after you have injectors out if you want, but it probably wouldnt start if it was under 300, and if you have that much there is some hope to turn it back around. If one is near dead, well, thats that isnt it?

If it were me, I would put an ounce of MMO in each cylinder while the injectors are out. If it has carboned up rings it would help free them up. Just be sure you spin it over on the starter before putting the injectors back in to blow the oil out. It will probably destroy the motor if you dont.

Hey Anchor Clanker,

Why would you recommend something that might "destroy your motor"?
Is that really worth the risk? Why not let some of the other Catalina owners who actually own a M 18 diesel engine offer advice that is specific to their engine, then just grasping at straws? Bad advice is worth less then none at all.

anchorclanker · Aug 3, 2012

jrowan said:
Hey Anchor Clanker,

Why would you recommend something that might "destroy your motor"?
Is that really worth the risk? Why not let some of the other Catalina owners who actually own a M 18 diesel engine offer advice that is specific to their engine, then just grasping at straws? Bad advice is worth less then none at all.

Grasping at straws? Bad advice? First off, I have been an engine mechanic for over 40 years. There is NOTHING about an M18 that makes it any different than any other diesel. That engine is used in a lot more than just Catalinas, and not just boat engines, but I degress.

Its a diesel. I know how they work and I know how to work on them. I told the guy what to do, what I would do, and over a month later hes still trying to get around doing all the maintenance that he has no clue when it was done last. Hit and miss approaches usually end up wasting a lot of time and money, and in this case time has likely already ran out.

But to better explain the procedure. If the engine has fouled rings, caused by heavy carbon deposits caught in the ring lands of the pistons, there are only a couple ways to fix the problem. Remove the engine and completely overhaul it. Remove the engine and replace it. Or try to unstick the rings and see if it will run decent again. People have been unsticking rings by that process, many times successfully, for over 100 years. Its an old remedy that you apparently have never heard of, because your not a mechanic, hence your comments of claiming I am giving bad advice, grasping at straws, and wouldnt know one end of a connecting rod from the other.

Ralph Johnstone · Aug 3, 2012

jrowan said:
Hey Anchor Clanker,

Why would you recommend something that might "destroy your motor"?
Is that really worth the risk? Why not let some of the other Catalina owners who actually own a M 18 diesel engine offer advice that is specific to their engine, then just grasping at straws? Bad advice is worth less then none at all.

Reading Anchoclanker's advice, he quite clearly states that the engine will probably be destroyed if one DOESN'T blow the oil out of the cylinders before replacing the injectors. We call this "hydrolocking". It occurs when the piston comes up against the incompressible MMO and tries to launch the head.

If one DOES blow out the oil before replacing the injectors .................. no problem.

Anchorclanker's advice on removing carbon from the rings seems well grounded, suggesting that he's "grasping at straws" perhaps not so.

kloudie1 · Aug 4, 2012

Valve clearance would probably not cause the symptoms .. but it should be verified before beginning a long chain of troubleshooting.. To get a pretty good "top dead center" to use for setting valves, use a mirror or whatever it takes to set it one time.. then carefully mark the front pulley with paint or a scribe .. use a fixed reference point on the front of the engine somewhere so you can duplicate the setting pretty closely after rotating the crank several revolutions.. be sure the fuel stop is pulled and the decompression levers (if available) are set so that the engine does not start and damage YOU. Marking the front pulley is generally is not accurate enough for checking fuel injection timing , but for setting valves, it is ok..
Sounds like it is time to get a good engine guy to look at setting the governor in the unloaded mode ..

jrowan · Aug 4, 2012

Anchor clanker,

If you are an engine mechanic, then why wouldn't you recommend that the first thing to be done is to diagnose the problem correctly, by getting a real diesel mechanic to perform a compression test on the cylinders, and checking the fuel pressure psi at the fuel pump. This is the only way to know the condition of the fuel delivery & the piston rings, not by pouring oil into the cylinders. That is a last resort measure. There are so many more obvious problems that typically occur before you go to the rings as a source of a problem. Checking the diesel fuel condition, fuel filters, fuel rate flow at the injector pump, checking the exhaust elbow for obstructions, etc. You assume too much by saying I don't know one end of a connecting rod from another. I too have had a lot of experience with diesel engines, as I have sailed boats with them for nearly 30 years. I have owned 4 boats with different diesels, and have also rebuilt several of them myself. So don't "digress" to personal attacks. If someone can't fix an engine after a month's time then it would be better advice to suggest hiring a professional to get the job done right, instead of suggesting to a novice that he pour oil into the cylinders, which will result in damage if it is not completely cleared before the injectors are restored. If you know the M 18 so well, then you should know that most problems with OUR engines are fuel related, not compression related. Another post by a M 18 owner states that he had the same problems & rebuilding the fuel pump solved it. Another simple suggestion I was going to make was to check the fuel pickup tube in the tank & make sure that there are no partial blockages in the fuel flow. My Universal diesel had these type of issues from inadequate fuel pressure flow to the engine, not a piston ring problem. If the rings were truly seized, his engine would probably not even start. Running at full throttle after thorough warm up can also help dislodge some carbon buildup caused by extensive low idle running. By the way, what type of engine do you have in your O'Day 22? I would think that the owner of a Catalina 30 with a Universal diesel might be able to offer advice specific to that engine which they own, with specific reference to how it performes within that specific model of boat. Specific information information & advice from sailors who actually own that model & boat is invaluable. Practical application & specifics to that model cannot be beat. That's what I'm trying to say. You of course can suggest anything you want.

Help me trouble shoot my engine!

.

.

.

.

.

.

.

.

.

.

.

.

.

Attachments

.

.

.

.

.

.

.