Bukh Dv-18-Me Running Cold

[zerubb]

Hi my engine is a Bukh DV-18-ME (18hp). The two previous owners of my 1990 Vertue used the boat infrequently; as a result the engine only has 260 hours. Now the engine starts first time and runs perfectly, but seems to run colder than one would expect. I have changed the thermostat, this made no difference. I have also noticed at the end of a recent 2 hour trip when I was forced to motor due to a lack of wind that a slight oil/fuel? slick was behind the boat, I only noticed this when I was in my berth and about to shut down the engine. I would appreciate any thoughts or ideas.

Regards

[MMNETSEA]

Originally Posted by zerubb' date='07 June 2010 - 02:56 PM

Hi my engine is a Bukh DV-18-ME (18hp). The two previous owners of my 1990 Vertue used the boat infrequently; as a result the engine only has 260 hours. Now the engine starts first time and runs perfectly, but seems to run colder than one would expect. I have changed the thermostat, this made no difference. I have also noticed at the end of a recent 2 hour trip when I was forced to motor due to a lack of wind that a slight oil/fuel? slick was behind the boat, I only noticed this when I was in my berth and about to shut down the engine. I would appreciate any thoughts or ideas.

Regards

If it is running colder after say 10 minutes in gear at s say 2,000 RPM - what temperature would that be? A diesel runs more efficiently when hot - many are design set to run between 180 <<>> 200 degrees F. No more than 92 degrees C.

Unusual fault! Cold. What is the flow of water from the exhaust like ? Cold ? Plenty?

Have you checked the oil before and after a day out on the water.

[zerubb]

Hi Thanks for your reply MMNET, Unfortunately no temperature gauge fitted, engine never feels more than warm to the touch; even after extended running, (not very scientific) Oil levels remain good with no sign of water or other impurities. Water flow is good hot or cold...Regards

[delatbabel]

No temperature gauge fitted for a diesel is a serious problem. Get one fitted asap. The engine might not feel more than hot to the touch because you might not be touching the hot parts, and if you're using your fingers as a temperature gauge get used to burned fingers.

A normally aspirated diesel should run within 5 deg C of 80C, and even prehistoric temperature control systems are pretty good at holding them to that. A turbodiesel should run between 85C and 92C. Anything else is a problem. My old Vetus with 5000+ hours on the clock runs at very close to 80C all the time, warm day, cold day, high or low revs. The temperature needle in my VW Caddy (turbodiesel) is almost never seen to flinch off exactly 90C.