How Can I Make Sure the Engine is OK?

[Sabbatical II]

Originally Posted by Driftwoods

We're looking at a boat and we quite like it. During the survey, we discovered all the engine gauges had been disconnected. It started up and ran well although it did overheat during the sea trial - no alarm sounded since it was disconnected too.

What can we do to make sure this engine is in good working order? Obviously just reconnecting the gauges is not going to cut it since we don't know how many hours are on the engine (disconnected too) and we don't know if it's been running in a overheated state for a extended period of time or if this was the first time.

Any input is appreciated!

If you love this boat, buy it but assume that you will need a repower and pay accordingly. And repowers end up costing a lot more than the "estimation" they give you because of all the incidentals. Even if you get an A grade marine mechanic to inspect it, he is not going to pull it apart so he can only give you an impression. I would assume that a motor that has had alarms disconnected and overheats on the test run, has been badly overheated previously (& on every subsequent test run) and therefore cannot be relied on. A known crook motor is a fantastic bargaining chip for a bargain price.

[Driftwoods]

Thanks Greg ...

Rather than rely on a inspection, even one from a top notch mechanic, would it be better to insist on at least a overhaul if not a a rebuild of the engine? The seller is willing to go pretty far to make this engine acceptable so I have some options (a total repower is not going to be one of them though).

When we surveyed the boat, the engine oil looked like it might have been put in there about a hour before we got to the boat, it looked like it does right out of the can. So now I wonder if even a oil analysis would tell us anything.

Would an overhaul give me the interior look at this that is meaningful?

[ohdrinkboy]

From afar it looks appears that someone is trying to hide a problem by disconnecting the panel and hoping it wouldn't overheat. I could be wrong.

[Sabbatical II]

Originally Posted by Driftwoods

Thanks Greg ...

Rather than rely on a inspection, even one from a top notch mechanic, would it be better to insist on at least a overhaul if not a a rebuild of the engine? The seller is willing to go pretty far to make this engine acceptable so I have some options (a total repower is not going to be one of them though).

When we surveyed the boat, the engine oil looked like it might have been put in there about a hour before we got to the boat, it looked like it does right out of the can. So now I wonder if even a oil analysis would tell us anything.

Would an overhaul give me the interior look at this that is meaningful?

Might I suggest that a repower with a brand new motor is usually better value than having a mechanic overhaul it. A brand new motor comes with a total warranty on everything inside it. A "rebuilt motor" is one that has had a mechanic pull apart, make subjective decisions about the likely longevity of some components, and put back together with fingers crossed. It is seldom cheaper in the long run and fraught with danger because of the "human element." If just one minor component that is judged to be serviceable, fails the week after the overhaul, the whole process is likely to need repeating and the mechanics warranty will cover only the work he did, not the work he didn't do, since its how the fine print on the back of the work order is written.

[Rakuflames]

Originally Posted by Driftwoods

We're looking at a boat and we quite like it. During the survey, we discovered all the engine gauges had been disconnected. It started up and ran well although it did overheat during the sea trial - no alarm sounded since it was disconnected too.

What can we do to make sure this engine is in good working order? Obviously just reconnecting the gauges is not going to cut it since we don't know how many hours are on the engine (disconnected too) and we don't know if it's been running in a overheated state for a extended period of time or if this was the first time.

Any input is appreciated!

Where I am, you can get an engine survey just as you can get a marine survey.

Wish I had known that then ...

[Rakuflames]

Originally Posted by Tingum

You are dealing with an overheating engine. That could or could not be a major problem. Hire a competent professional and by all means insist on the oil analysis. Then make your offer based on facts not guesses. Fair to both you and the seller.

This is really true. My boat had a saltwater cooled engine, and it turned out (eventually) that the overheating was caused by multiple problems, some of which could be traced back to lack of zinc maintenance.

I had to get a new engine.

Unfortunately I didn't know about engine surveys at the time.

[Target9000]

Originally Posted by Driftwoods

Thanks Greg ...

Rather than rely on a inspection, even one from a top notch mechanic, would it be better to insist on at least a overhaul if not a a rebuild of the engine? The seller is willing to go pretty far to make this engine acceptable so I have some options (a total repower is not going to be one of them though).

When we surveyed the boat, the engine oil looked like it might have been put in there about a hour before we got to the boat, it looked like it does right out of the can. So now I wonder if even a oil analysis would tell us anything.

Would an overhaul give me the interior look at this that is meaningful?

I doubt the owner would pay for an overhaul for a sale? Why not just chop some of the price and let the next guy do it? And from your standpoint, you'll want to have the piece of mind selecting the shop and the parts, etc during the overhaul anyway. Deals like this are cut in the purchase price. Its all a dollar amount on uncertainty.

My .02 about the motor...

Lets ignore the fact that the gauges were disconnected (which is a huge deal but merits a different type of discussion).... The motor overheated on a sea trial.

Every time an engine runs above its specs there is a chance for stuff to go wrong. Gaskets can break down. Metals warp. Seals give out. Oil burns, etc. Now someone had just taken care of this motor (hopefully) and changed its oil (possibly), but it still overheated. Even when on its show day.

Do you think it MAY have overheated before? Do you think repeatedly running above normal op temp could have repercussions? I sure do. And unfortunately, short of taking the head off the block to check for warping or bad gaskets, not sure what else you can do to see what type of damage may have come from that sort of thing.

Check the easy stuff first though, you don't need a mechanic to:

check the impeller
check the state of the heat exchanger tube
check the motor zinc
look at the fuel filters
send an oil sample for analysis (run the motor a bit with the fresh oil before taking sample)
look over maintenance log book
look at the motor mount conditions
feeler gauge the shaft coupler to check alignment
check the state of the propeller
etc

All of those jobs are simple and things you, as a boat owner, should know how to do anyway and chances are they may provide clues into why the motor overheated and what the other states of maintenance were.

[MarkSF]

Can you go into more details about what you did with the IR gauge? What readings you got, and where? Those things can be very inaccurate.

They do not give accurate readings on any bare metal due to large variations in emmissivity of metals. I've even seen 50F difference between anodised and bare aluminium.

It IS possible to get reasonably accurate readings on rubber hoses. If you want a reading on metal, tape a piece of black insulation tape to it and take the reading off that.

[perchance]

An engine survey will only tell you so much. Even the best mechanics don't have X-Ray vision. The new condition of the oil could be just a case of the owner doing his annual service before he hauled out.
A properly rebuilt engine is almost as good as new provided the engine builder doesn't cut corners. If the idea of rebuilding doesn't appeal to you, you can opt for a re manufactured engine from an authorised dealer or a complete new re power depending on the depth of your pockets.

[ranger58sb]

Of course there are conditions that can't easily be determined without a complete teardown... but there can be a difference between "a professional mechanic" or a "diesel guy" and a brand-certified technician. The first guys can be pretty good, but that doesn't necessarily mean they're specifically familiar with the engine brand/model in question... nor with any known wear points or service bulletins. Our main engines are Cummins diesels, so our mechanical survey was performed by the local Cummins distributor. Long punch list of correctable stuff; they knew what to look for. But yep, no guarantees.

I meant to add above that engine oil analysis can indeed be a good thing, can tell you something about the condition of the engine... but generally oil analysis is a long-term analytic tool, so you can monitor engine condition over time. IOW, a one-time-shot isn't the only way to use oil analyses.

-Chris

[rtbates]

Hire a marine mechanic OR RUN LIKE HELL!!

[Boracay]

Ask the owner to reconnect the gauges and to fix the overheating problem.

If they do see if you can talk to the mechanic who does the work.

Then repeat that part of the sea trial that caused the engine to overheat.

[Driftwoods]

Thanks for all the info. Great, great stuff. I'm a total noob on the whole diesel engine aspect of boats but I'm learning fast.

The seller is going to reconnect the gauges, alarms and do whatever it takes to fix the overheating problem. We'll have access to the mechanic that does it for any questions. I'm putting together a list already from some of the above feedback but if anyone has suggestions for questions to ask I'll ask those too.

After all that gets fixed, I found a Yanmar certified mechanic that will do a engine survey (hiring that one on my own dime so he's "my guy"). We're gonna beat that engine up a bit and see what shakes loose. He sounded kind of excited about it ... I like that.

It's not tearing into it and seeing the guts of it all but it should tell us a lot and it's about all we're gonna get. After that, we'll have to put some serious thought into the test results and recommendations and see where that leaves us.

[Rakuflames]

Originally Posted by ohdrinkboy

From afar it looks appears that someone is trying to hide a problem by disconnecting the panel and hoping it wouldn't overheat. I could be wrong.

I got that feeling too.

[rolandgilbert99]

Originally Posted by Driftwoods

After all that gets fixed, I found a Yanmar certified mechanic that will do a engine survey (hiring that one on my own dime so he's "my guy"). We're gonna beat that engine up a bit and see what shakes loose. He sounded kind of excited about it ... I like that.

I had a Marine Diesel specialist with a solid reputation look at my engine oil leaks, he charged me an arm and a leg to go around the engine with his spotlight and let the engine run for an hour. He could never tell me where the leak came from, he made guesses that had to be verified with additional $$$$. He could not tell me if the engine was in good health from the survey. He offered me to rebuild my engine or sell me a new one for $$$$$. I am sure your mechanic is excited about your business, for him it's more $$$$$ to come!

By the way I had my engine and tranny factory rebuilt (not by the mechanic mentioned above) for a little over $12K, buying a new engine and getting all the adjustments to fit it in the engine compartment would have costed me at least $26K.