Starting to hate boating

Hi,

You have luck on your side with those engines.

They are based on a virtually bullet proof Mercedes Benz base.

Think yourself lucky they are not one of the new fandangled 2 or 4000 series that I am reading so much negative stuff about.

Also , Would you happen to have any soot leaks in your exhaust system? This will kill filters quicker than look at them.

The MAN version of this engine has some real nice K&N air filters available that are washable. See if they might be available for the MTU?

Those airseps can be washed also. I use sep 60 ,I think it is, and the red oil they sell is nothing more than colered mineral oil

If it isn't the filters the injectors may be the culprit. Had a good friend have a similar thing happen, lots of smoke, lower WOT turns. Engine manuf. (MAN not MTU) went through their usual checklist; dirty bottom, bent wheels, filters, 1000 hour service, excessive weight, bad fuel etc. to no avail.

What it turned out to be was partially clogged injector tips, one or more holes not the entire injector failing. Unfortunately this is usually not detected during the injector short out test which looks for specific rpm drop when each injector is shut down. Seems a stale/dirty load from a seldom used travel tank had made it's way past Racor primaries, MAN primaries AND on-engine 2 micron secondaries! Small trash particels clogged random orifices in the tips which showed by uneven spray pattern on the tops of the pistons. Swapped out both sets with new (24 total, OUCH!) and cleaned her right up.

For some reason no one has the facilities to test the newer common rail (or HEUI) injectors except the factories themselves and replacement is the only option left unless you want to wait a long time for test/rebuilding if it's even offered.

A thorough borescoping may reveal individual ones that have uneven spray patterns and possibly a heat gun on the manifold comparing EGT on each cylinder can also show which ones are hotter or colder than the average. Not sure if that's possible on that engine or not though.

Ugh, you may be right about that. I had really hoped it was those nasty filters since the alternative can be expensive. At least taking a look at a couple of injectors and crowns is a good idea.

How old is the fuel?

Hi,

It is pleasing to read that there is some light at the end of the tunnel.

Ugh is right! 5K doesn't sound too high for turbo work, a grand a pop for CAT cartridges is pretty much normal on C-32's plus labor. The problem is definitely with the port engine, 300 rpm difference is putting a huge load on the stbd engine. I presume they want 2350 or so, fix the port and you'll be well into the governor on stbd at WOT.

Low boost pressure isn't always due to turbo vane clearance but it can be. Just as often the low boost is because she isn't flowing enough exhaust to spin the inlet side to generate boost pressure. Did they do a full load test on each engine independently to see what each would turn up on it's own? That should quicly show the port as the much weaker engine, a big difference in achieved rpms would confirm that.

Not sure about those particular engines and my MAN dealer next door has gone home for the night so I can't ask him if the turbo's can have the vane tip clearance mic'd like the other brands to verify but it sounds like some "trouble guessing" may be going on. I'll ask and get back in the AM.

bolt loose or missing?

Hey Dave,

I fought the same thing with a starboard engine last year for nearly 2 months. She would get on plane in the right sea conditions, but only because the port was strong, and even then lagged behind by 300rpm. Tried everything you have done thus far. Resigned to idling around at least to be on the water while working to solve the matter. All finally pointed to the turbo, even though it spun freely.

Then as I began to remove the turbo, my eye caught an open hole across the valley (3208's) on the air cooler/intake flange to the head. Sure enough, there was the bolt and lock washer lying below on the block. The bolt above it was loose as well, but still in place, and the 2 opposite were tight.

Put the bolt back in, torqued all 4, went out for a run and all the angels sang as if there had never been an issue. It simply could not build boost until it got up enough rpm to overcome the air leak.

Felt like an idiot, but at least I was boating again. Not at all assuming this is your issue, but it is a cheap look and fix.

Evan

I feel your pain

I travel a lot so I don't get to be on my boat too often, but lately it seems like every time I do get to go out, I have an issue and it's killing the desire to go out. In the last month alone, I've had my generator go out. My freezer stropped working after that. Last week, a guest tied up to a buoy with the line over the bow rail and it bent. Today I was picking the **** thing up from the welder's and then my controls took a crap. A man can only take so much.

Dave, I am not familiar with the machining and resleeving of the turbo housings. Does this hold-up well? Have you heard of any failures?

Thanks,

Saul

I have seen the problems you're experiencing and have seen a stuck open waste gate as the culprit on a Man 1350.

Easy to say that boats love to be run, but I have a different perspective.

I am convinced that overall stuff breaks at *exactly* the same rate, used or unused, but it feels much better to fix things that have broken whilst use, than those broken unused. Yes, probably different things break, but it feels ok to break things while you were having fun.

We use our boat nearly every weekend (except for the last awful year), and fixing stuff is completely expected.

Resentment only builds when you get bills/disappointment without the compensating enjoyment.

This past summer one of my engines developed an aftercooler leak. FIxed that with a new one. A month later the hot water tank started leaking (a ****** Al tank) and fixed that too by buying a new one. Then a month later the master shower hot water line started leaking - fixed that too. All was good until the vessel hit its ninth birthday. I can't wait until the boat becomes a teenager. But gosh it is fun and sure beats mowing the grass and raking leaves!