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Dear Tom, You might be interested to share with your readers my experience having a boat surveyed and what I think was a fairly unusual discovery that took some time to actually figure out. About two years ago, I had a 54’ motorsailer surveyed for me by a really well known surveyor in the Portland, Oregon area. The boat was a fairly new boat, built in 2000 and equipped with a Volvo turbo engine. Everything about the boat looked really good to me. The sea trial went well, no problems or surprises. When we returned from the sea trial I did notice a layer of soot on the transom around the exhaust. When I asked the owner of the boat, he said it’s always sooted up a bit so he never worried about it. I chalked it up to hull design. The exhaust is beneath the transom platform, which made me think the flow of air around the stern when the boat was moving was causing the exhaust to back up and stain the transom. After consulting with the surveyor, I decided the problem has to be a bad fuel problem. That conclusion was further reinforced when the owner told me he has been using heavy bunker fuel! The filters needed changing every 20 hours. This had to be the problem. Dirty fuel will do this, I kept telling myself. Bad fuel will clog the filter, which in turn, will cause the engine to starve a bit, causing uneven burning of fuel, giving the black smoke. Little by little, the black transom subsided, but not totally. After months of fighting the dirty fuel the transom still would have soot. I began to think that it was a function of hull design and it would never go away. This year things finally came to a head. The transom was getting blacker, and then a new symptom developed that really woke me up. The engine is a newer Volvo with some safety devices built in. If there is a problem when running, the engine will go into a “get home mode.” It won’t go above 1500 RPM. That’s what happened to me. Here I was running along at my cruising RPM of 2300 RPM, when the smoke became visible, pouring out of the transom. Then the engine went into get home mode. We slowly made our way back to the dock, watching smoke billow out of the exhaust. My friend’s response was the turbo was blown. No sooner did I get back to the dock when he was there ready to pull off the turbo and see what he could see. Pulling off the turbo is a big job, not one to undertake with a few wrenches and screwdrivers. I decided to try and get to the mechanic’s dock (about 20 miles away) and have them take a look at it before doing any major surgery. The boat made it there in “get home mode,” leaving a smoke screen behind us. The mechanic found the gasket for the intake manifold cracked, causing air to escape, preventing the proper boost pressure, which will cause improper burning of fuel, and therefore exhaust smoke. It was an all day repair, removing half the engine to get to the manifold. When the mechanic finally made his way to the manifold he found two bolts holding the manifold to the block were sheered off and two bolts were missing. The manifold was being held on by only three bolts! That was eye opening, I never would have seen or known that and I can honestly say there was no way the surveyor could have seen the problem unless the sheered bolts were in the bilge, which they weren’t. The sun was setting by the time we were ready to go home. I felt a lot better and was anxious to get back to my dock. I had planned a cruise up north and wanted to be on my way. The mechanic untied the dock lines and off we went. I idled past the marina and started to power up when all the engine would do was 1500 RPM. I looked aft and there was the smoke, following me like a killer fog. My friend and I looked at each other and didn’t say a word. I turned the boat around while he got on the cell phone to the mechanic. As we got closer to the mechanic’s dock, we could see him standing there with the same look on his face as we had. No one said a word. The mechanic jumped aboard and off we went. He dove down into the engine compartment and found a small air leak in a boost relay, a $25.00 part. He plugged the hole with 50 cents of epoxy and we were up and running at full speed again. We got it this time! It felt really good to be cruising along at speed, but I did watch the gauges more than the water ahead. It was dark by the time we made it back to the dock. The first thing I did was jump off the boat and look at the transom from the dock. It was black! OK, so we must have a bad injector along with the other problems we fixed. I decided not to worry about it and run tomorrow at first light. My plan was to sail as much as possible anyhow. Well, you guessed it. I was about 10 miles from home when the engine went into “get home mode” again (and no wind). Smoke began billowing out about as heavy as the weight I felt on my shoulders. I sunk down with the feeling of total gloom and doom. We made our way back to the dock. One hope I had was from a past column of yours regarding exhaust back pressure. Back pressure could be the problem. I took apart the exhaust, hose by hose, and expected to find something, anything lodged in there. Nothing, the exhaust looked fine. I made my way (slowly) back to the mechanic, tied up the boat, walked off and got a ride home. My worst thoughts of turbo, injectors, manifolds, and other assorted engine parts raced around in my head. I had given up and asked the mechanic to do what he could and call me when and if he found anything. I got a call the next morning from the mechanic’s office manager, the boat was ready to go home. Driving back to the boat I had very mixed feelings. I felt as if I had been on a roller coaster ride, up and down. I hoped for the best but expected the worst. I kept calling the mechanic to find out his results but he was gone for the afternoon on another job. When he did call me he said the boat was ready. I asked impatiently what the problem was. He told me the air cleaner/filter was clogged. I couldn’t believe this oh so easy fix, and said I had replaced it two weeks ago. He said in his typical low key, self assured voice, yes it was the air cleaner. He took the boat out on a sea trial and became frustrated with the problem and kicked off the air cleaner. The difference was night and day. The boost pressure was where it should be, no more smoke and lot’s of power. A dirty air cleaner! Granted there was a primary problem with the intake manifold gasket, but what happened was because the exhaust smoking escalated, it began to find it’s way into the engine room through air intake vents on deck and clogged up the air cleaner. As it did so the smoking problem became worse and worse, which clogged the air cleaner even more. I think this is a classic case of Murphy’s Law. Tom, I hope your readers will get something out of my roller coaster ride. As the mechanic told me, it is usually the simple things even with these new high tech electronic engines. It’s been six months since that event. The transom is clean and no smoke. I now have a clean running engine. Frank Allred Olympia, Wash. Ask the surveyor Live and learn. My feeling is if you use any machinery, you will be faced with the unknown at times. The newer electronic engines have the ability to diagnose a problem if it develops, either by gauges controlled by the engine’s computer or through the exchange of information from your mechanic’s laptop plugged into the engine. Really cool technology but the simple causes will not show up in the diagnostic instruments. Sounds like you have a mechanic that has more than by the book knowledge. He has an instinct and the field experience necessary to solve your rather simple yet complicated problem. Tom Averna is an independent marine surveyor, specializing in sailboats. He can be reached at 1-800-544-5758, emailing him at: chartert@rockisland.com or by writing him a letter to this magazine. ...back to 48° North title page. |