I have a 1983 Yanmar 2GM raw water cooled engine. When the ambient temperature drops below 45-50F it won't start unless I'm at a dock and can put a hair dryer into the air intake. Can glow plugs be used on such an engine? I couldn't find a location on the engine diagrams.
Yanmar Glow Plugs
- Thread starter sailhappy20778
- Start date
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,078
The Yanmar 2GM diesel engine does not use glow plugs.
It relies on compression ignition. The 2GM model is known for starting well without glow plugs. This is due to the relatively high compression ratios and efficient design. In cold climates or if the engine is hard to start, some versions may include or be retrofitted with an intake air heater (thermostart), but this is different from glow plugs and not always standard. That would be why your Hairdryer trick works.
If you’re having trouble starting it, common culprits include:
It relies on compression ignition. The 2GM model is known for starting well without glow plugs. This is due to the relatively high compression ratios and efficient design. In cold climates or if the engine is hard to start, some versions may include or be retrofitted with an intake air heater (thermostart), but this is different from glow plugs and not always standard. That would be why your Hairdryer trick works.
If you’re having trouble starting it, common culprits include:
- Air in the fuel lines
- Weak battery or starter
- Poor fuel quality
- Valve or Piston wear - lack of adequate compression
Somewhat familiar with the starting ability of a cold 2GM. What worked for me was to move the throttle to 3/4 max then begin to crank the engine. It often took up to ten cranking seconds before the engine would start to fire. Once it did, then I moved the throttle back to about 1/4. Never a problem when warm, just during the cold winter months. Try that to see whether it makes a difference.
Hard starting on the GM series is usually indicative of other problems, even when cold. In no particular order: adjust the valves, service the injectors, confirm that the fuel system is clean from end to end, and there are no leaks. As John noted above, a weak battery can cause hard starting, as can undersized cables, corroded terminals, or loose connections at the battery and starter terminals.
If you have easy access to the engine and air intake, you can try heating the air at the intake before trying to start the engine. If you have AC power, blow a hair dryer into the intake. If you have some help, keep the hair dryer on while you start the engine. If no AC power, use a lighter or something to heat the air. Remove the filter first!
Then Terry’s notes on throttle settings are good recommendations.
Greg
Then Terry’s notes on throttle settings are good recommendations.
Greg
I had the same problem with a 3GM in my last boat. A Yanmar mechanic gave me a tip that worked.
Crank the engine for 10-15 seconds while holding the stop button (or whatever other means you have to prevent it from starting). The compression warms the heads. Then wait 30 seconds to 1 minute to let the heat distribute. Then try to start it. This worked well at 50 F, anything colder and it took a couple tries.
Crank the engine for 10-15 seconds while holding the stop button (or whatever other means you have to prevent it from starting). The compression warms the heads. Then wait 30 seconds to 1 minute to let the heat distribute. Then try to start it. This worked well at 50 F, anything colder and it took a couple tries.