Report from the Diesel Doc

  Friday, August 31, 2012 / Brian / Maintenance  

While Stephanie and I were enjoying the dockside life last night Rode Trip was nervously awaiting her first check up by a real professional since 2009. This morning Gary our mechanic arrived right on time at 7:30 and asked for all the details. I gave him all the information that my equipment troubleshooting had enabled me to collect. 1. After we had been running the engine for a while the oil pressure would drop slowly 2. When the oil pressure dropped the oil level in the tank would go up. 3. We were collecting approximately 3/4 pint of additional volume every 3 weeks/20 engine hours 4. The engine seems to still start and run normally other than the fact that we were "making" oil 5. The tachometer fluctuates slightly (50 rpm) for the first 30 seconds to a minute after starting the engine. Gary listened carefully to all the details that I gave and started asking questions. He still wasn't sure, but we moved on to looking at the engine. His first reaction was " this engine looks like it is in great shape". After taking a quick look around he had me start the engine, he looked for a smoky exhaust, or a hard start. Our good old perkins started up right away, just like usual. He made another comment that most Perkins require quite a bit more cranking than that to get going. He reassured me about the fluctuation in the tachometer. Apparently our tachometer reads off of our alternator and if the engine belt slips at all then the tachometer will fluctuate, but the engine is really running fine. I suggested that I would tighten the belt later, and he said that it would be better to leave it the way it is, better for the alternator. After gathering all this information his opinion was...that it almost had to be a bad fuel lift pump. We talked about how that had recently been replaced with a new unit. He suggested that with the symptoms that we were having it seemed most likely that we had been sold a bad fuel lift pump. We made a plan that he would check the new fuel lift pump first, and then move on to the injectors. While he was starting the fuel lift pump check he found that we had a glow plug (fuel preheater for starting the engine in cold weather) that he missed on his initial inspection. He decided to check this first as it was very easy to pull and check. His check indicated that the valve inside was most likely leaking past! Whew! Talk about relief, it seems that our problem was caused by one small valve that we don't need and weren't using. Ten minutes later the glow plug was replaced with a bolt, and I have instructions on how to install a new glow plug if we decide to do some cold weather sailing. I was ecstatic! I had been convinced that we were going to be stuck at the marina here at Point Judith while we waited for parts and had to have major engine work done. Instead the mechanic was done in about 1 1/2 hours, we didn't have to order any parts, and I got some of my lingering engine questions answered. 1. There are no pencil zincs on our engine or raw water cooler 2. The prop will always spin slowly even when we are in neutral. 3. The transmission fluid should be changed every 1000 hours approx I also asked about what usually breaks on a perkins, and he told me "nothing, these engines are just about bulletproof" Thanks to Rich and Carol for recommending Point Judith Marine. We were very happy that our problem was solved so easily, although I imagine that the marina was probably hoping we would at least have to buy some parts after we stayed at their dock and used their showers!


  1. From Maggie on Sep 06, 2012
    Such a Chemist!!

  2. From admin on Sep 01, 2012
    That makes sense. The water heater in my travel trailer has something similar, they call it the sacrificial anode rod.

  3. From Brian on Aug 31, 2012
    The mechanic seemed a little dubious of the effectiveness of the glow plug on a marine diesel, and wasn't hesitant at all about capping it off for us. We don't plan on being anywhere cold enough that we will need it in the near future. Anytime that 2 different metals are in contact with each other and immersed in salt water one will start to corrode. If you add a piece of zinc it will corrode first and save the other metals...sounds like a post on electrolysis is in order.

  4. From Brian on Aug 31, 2012
    We're happy to keep making posts! It has been really neat to see the coastline start to changeover from Rocky to more sandy beaches. We especially like the fact that the water is getting warmer!

  5. From Brian on Aug 31, 2012
    Dark and Hoppy at the same time...that sounds fantastic! I think we are going to have to take our kayaks ashore right now and look for something like that.

  6. From admin on Aug 31, 2012
    Automobile diesel engines all have glow plugs since they have to deal with cold weather. But it makes sense it's not a requirement for you. Glad the fix was so easy; has to give you great confidence going forward. What is a pencil zinc? --Mark

  7. From Sue McGown on Aug 31, 2012
    I have loved following your adventures down the New England coast! Seems like a long time ago when you were in the quiet rocky harbors & coves in Maine. Have safe winds & a following sea........& keep posting those blogs for all of us to travel with you.

  8. From Dennis on Aug 31, 2012
    Fantastic news!! So glad it was something small and easy to fix. I was thinking about you guys when I cracked a new home brew last night, dark and hoppy........