I have a 9 HP Yanmar 1GM10 that had cold starting issues at any temperature. As the engine cranked, the mechanical fuel injection system kept pumping fuel into the cylinder, and when it would finally “catch,” it would backfire (some believe to be impossible in a diesel engine) and shred the foam air filter. After started and stabilized, the cold-engine white smoke would foul the air for a minute or two.
I thought of having a costly maintenance done, starting with rebuilding the injector (still not a bad idea for an engine with nearly 800 hours on it), but I kept getting mixed messages on the advice from marine engine mechanics and other sailors. I finally decided to look into this issue in a different community of knowledge. I went to my local Kubota tractor dealer and described my problem. I was referred to a knowledgeable person who said that I should hold off on the expensive repairs until I try using an oil pan heater – the bottom-mounted kind, rather than the dipstick kind. I liked the idea of trying the less-expensive option first, and I thought that the worst thing that would happen is having warm oil to prolong the life of the engine, which is actually a good thing.
The operational concept is simple; the heating pad is mounted at the lowest part of the engine, which heats the whole thing, not just the oil. Diesel engines love heat, and having a warm engine helps it start. Some alternate starting solutions, more complex and costly, use intake air heaters to help cold starts. I also decided that these more-complex solutions would provide more exposure to maintenance problems.
These heaters are a seasonal item, so they may be hard to find until the fall season. I found what I was looking for on Amazon.com, though. It is a Kats 50 W self-adhesive pad heater http://www.amazon.com/gp/product/B000I8YPQ4/ref=ox_ya_oh_product which did the job. Kats and Wolverine both manufacture these heaters, and the Wolverine site http://www.wolverineheater.com/products.shtml recommends 50 W heater for 1 - 2 qt capacity (the 1GM10). When I mounted it, the 2 x 5-in pad fit the bottom of my oil pan perfectly, edge to edge.
The installation was simple. The paint on the surface to adhere to must be sanded off, and a non-acetone solvent (I used denatured alcohol) is used to clean the freshly sanded surface. At that point, all that is needed is to peel off the adhesive backing, align the pad, press it onto the bottom of the pan, smooth out any bubbles, and plug it in. A 110 V outlet in the engine room provides a clean installation.
The next day, I started it in the first 2 or 3 seconds of cranking (it used to take about the same number of minutes), and there was no white smoke. I have been using this heater for months now, and I absolutely love what it did to my little engine. I feel so strongly about the benefits that I decided to take the time to write this posting. No, I have no financial interest in any part of the heater manufacturing. If you want to prolong the life of your engine and have a better-behaved cold start, you should consider taking a few dollars and minutes to apply a heating pad.
I almost forgot, for me running a 50 W heater around the clock for one month, the additional electricity is approximately $1.80 at $0.05/kW-hr. So, both the non-recurring and recurring costs are very low.