Diesel starting procedure

[Stan]

I know this is a basic question. But I need an answer.Last August we took delivery of a new Catalina C320. After reviewing all of the systems with the Dealer he started the 3 cyl. Yanmar let it warm up (no load) for about five minutes.This went against everything I learned about starting a diesel. I was taught to fire up the engine and immeadiately put a moderate load on it. In fact I was taught never to let a diesel idle without a load on it. My understanding is without a load the blow-by is excessive and the oil is quickly fouled. After questioning my Dealer on this he repeated the need for a "no load" warm up. This is how we started the engine the rest of the year. I would sure like to have a definitive answer before we put her back in the water in April. I just have a hard time letting a diesel run "unloaded". Am i right of wrong??

 

[hp]

starting your engine!

this is just my personal belief but no engine should be operated without a short "warm up" period. It should be just so that the water and oil warm up before placing a load on them I think five minutes is not going to much of a blow-by problem. I just put mine at a idle speed of 900 to 1000.It won't reach operating temp but it gives me a chance to check things (exhaust water flow,check for fuel,water leaks,general condition) Hope this helps Pete

 

[Ron Thom]

Diesel warm up

I agree with Pete. Long before I got my boat, I took an 'air brake' course to drive large trucks. The instructor insisted on warming up the diesel truck motor at no more than 1000 rpm until the everything was warm etc., this usually took about 5 minutes. With the Universal 11 h.p.in my Cat 30, I warm it up until the water temp gauge reads about 145, again about 5 minutes. Well that's my 2 cents worth. Have a great new year and a happy & safe boating season!

 

[Gordon Torresen]

Wrong!!

Letting things get up to temperature is always a good idea. You may get there by idling or with a light load. Blowby is exacerbated by loading. If the piston could get out of the way as fast as the fire burned there would be no blow by. This obviously cannot happen but the more resistance there is to piston movement, the greater the blow-by pressure. Enjoy the boat. With proper maintenance that engine will last a long time, warmed or not, loaded or not.

 

[Sam Lust]

Just to ad some confusion

The Yanmar Owner's manusa does recommend warming the engine before putting it under load. Now the confusion. The Oil maker I spoke to suggested strongly that with the recommended multi-grade oil the engine should not be subjected to full power until the oil is warm, which occurs well after the water is warmed. Something about long polymer chains and such. Once fully warmed the oil reaches it's full (and superior) lubricity.