Over Heating a Yanmar 3gm30F
- Thread starter NCBrew
- Start date
Many different things….
But a few questions to help us narrow things down…
1) are you getting good water flow out of the exhaust? Lots of potential causes, and this would certainly cause overheating.
2) Do you have AF in the heat exchanger? Is there some AF in the overflow tank? I bought a boat and was motoring it home…a30 minutes into bashing. seas on Lake Michigan, engine alarm went off….engine overheated. Nursed her into the closest port, and found nothing in the HX. So I know this can cause Heating issues.
3) is the bottom and prop fairly clean? Overloaded ngine could run hot.
4) Any smoke, oil, or other stuff in the exhaust? Something mechanically gone wrong in the motor?
Give us a little more and we can narrow things down for you.
Greg
But a few questions to help us narrow things down…
1) are you getting good water flow out of the exhaust? Lots of potential causes, and this would certainly cause overheating.
2) Do you have AF in the heat exchanger? Is there some AF in the overflow tank? I bought a boat and was motoring it home…a30 minutes into bashing. seas on Lake Michigan, engine alarm went off….engine overheated. Nursed her into the closest port, and found nothing in the HX. So I know this can cause Heating issues.
3) is the bottom and prop fairly clean? Overloaded ngine could run hot.
4) Any smoke, oil, or other stuff in the exhaust? Something mechanically gone wrong in the motor?
Give us a little more and we can narrow things down for you.
Greg
Here are 10 possible causes to add to @Tally Ho list:
10 Common Causes Of Marine Diesel Engines Overheating
I had a 3gm30f on a prior boat. It always ran at around 180 degrees at cruising speeds. Slowly the temp began to creep up over several months. Eventually I had to reduce the rpms to 2000 or less to keep at or below the 180 mark. It turned out to be a blockage at the top of the mixing elbow where the raw water enters. #2 on Hello Below"s list of possible causes.
Having really overheated mine due to the water pump impellor destroying itself I would say the possibly is pretty good.
I had an old hose on the fresh water cooling loop that would leak coolant went the engine got up to pressure at normal operating temp...low coolant level will definitely cause a high temp alarm.
I have a 2GM20F that started to overheat on me quite a number of years ago. I found that the antifreeze coolant was low, so I refilled it, but it kept going down (slowly), but it was not leaking inside under the engine. Long story short I removed the Heat exchanger, thinking there was a leak in there. I also used an antifreeze flush to clean out the system. When I put it back together with new gaskets and O-rings, it still leaked. I put a recommended amount of Barr’s Stop Leak in and the problem has never come back.
I used some stop leak on a car heater core and that prove to be a permanent fix as well.
Sir Michael
I used some stop leak on a car heater core and that prove to be a permanent fix as well.
Sir Michael