Mechanic coming to look at my engine. What else should I do?

[Juanona]

I have a mechanic coming to do a couple minor jobs I don’t feel comfortable doing on my own. While he’s here I plan to have him adjust the valves and check the mixing elbow. I’m debating asking him to do the following. Is it needed and is there anything else I should have him look at? The engine is a 1988 Yanmar 3HM35F and is running fine. Sometimes I see hints of black and/or white-blue smoke. It has 5500 hours. Was rebuilt in 2001 at 2700 hours.

Check compression? (Last checked Oct 2011 900 engine hours ago and was fine)
Check injectors? (Last reconditioned May 2007 1100 hours ago)
Anything else?

Thanks. I will try to check the board more frequently now that we’re settled into a marina for the winter in Holland.

Max

 

[Don S/V ILLusion]

Be careful what your expectations are - a mechanic onboard your boat can't check injectors with his typical toolbox. Buyout might consider asking him to replace parts which wear, e.g., water pump, belts, tensioner, impeller, alternator brushes, check motor mounts, etc..

 

[TomY]

Hi Max, you know I'm not a mechanic. Obviously you'll have him look at obvious things form problems.

If the engine is running fine, starts quickly, no changes, I'd let sleeping dogs lie (skip the compression test, injectors give warning service is due).

Send us photos from Holland, please.

 

[Juanona]

Yeah, after thinking about it I’m going to hold off touching the injectors and doing the compression test. The mechanic is highly recommended so having him do a couple basic things will give me a sense of him in case I need anything more serious in the next few years that we’re around here.

 

[NYSail]

I had the same engine on my last boat..... change all hoses, mixing elbow, check mounts and alignment, check valve clearance, hoses and belts. My engine had no smoke and ran like a top. Great motor!

 

[CarlN]

In my experience, anytime someone touches my engine, there a 25% chance of something being worse after they've left that means they have to come back. The more they touch the greater the chance. So besides doing the routine, I think the best reason to have a great mechanic look at your engine is 1) they are experienced enough to notice something that isn't "right" - I once had a mechanic hold up a tiny screw he saw in the bilge. "That's Yanmar grey" he's said. After a bit of search he found it held an injector tubing bracket on - and all the nearby screws were also loose. 2) They can tell you exactly what to watch for on your engine. The same mechanic pointed to a spot on the manifold. He said "If you ever see a drop of coolant or rust right here, it needs to be fixed right away."

 

[Dave Gibson]

What TomY said. If it ain't broke, don't fix it.

 

[py26129]

Hi Max, you know I'm not a mechanic. Obviously you'll have him look at obvious things form problems.

If the engine is running fine, starts quickly, no changes, I'd let sleeping dogs lie (skip the compression test, injectors give warning service is due).

Send us photos from Holland, please.

Tom
For my education, what are the symptoms of an injector needing service? The background to the question is that I have my engine in my garage for the winter and was considering having the injectors checked while it was out of the boat.

Thanks in advance

Matt

 

[TomY]

Tom
For my education, what are the symptoms of an injector needing service? The background to the question is that I have my engine in my garage for the winter and was considering having the injectors checked while it was out of the boat.

Thanks in advance

Matt

Hi Matt, I would think unburned fuel making for a black smoky, sootier exhaust. Running rougher and maybe slow starting, stuff like that. Mostly when injectors are needing service it's a sloppy spray pattern and dribbling that results in uneven combustion.

I had them serviced once because of the above problems.
But like I said, I'm no mechanic.

 

[py26129]

Tom
The symptoms make sense. I have had two boats with Yanmar diesels (YSE8 and now 3GMF) and both have had sooty bums. I had the injector checked on the YSE8 and it was pronounced fine. The 3GMF runs and starts fine, so I assume the injectors are fine. I will mull this over for the next few months to determine whether being sure of the state of the injectors is worth messing with them. My first instinct is no.
Thanks again
Matt

 

[Juanona]

The mechanic came by and agreed with what many of you have said: “if it’s running fine and sounds fine, little or no smoke, no need to pull the injectors” and no need to adjust valves if they aren’t making a noise. He is going to come back to check the mixing elbow, and on his recommendation we will replace the exhaust hose which is starting to crack. Something that I hadn’t really noticed so glad to have some fresh eyes on the engine as Carl pointed out.
Thanks for the discussion.
Max