'Normal' operating Temp and Pressure

[D & C M]

At last we have been able to get a week on our 2010 R25 so this has been the first time to run the Yanmar under differant conditions. In the manual I found that an alarm is trigered when the temperature is over 210F, but no mention about the 'normal' expected temperrature or oil pressure. I have been used to a sail boat diesel that gave constant readings what ever the rpm. I have found that at 1500rpm the Temp was 194F and pressure 30, 2000rpm 200F and 50, at 2500rpm 205F and 60 at 3000rpm 207F and 65 and at 3500rpm 209F and 65. The coollant is full and there appears to be plenty of raw water. Are these temperatures too high at increased rmp and the pressure too low at low rpm do I have to worry :?: Fortunatly we tend to cruise mostly around 2000rpm.
Dave and Chris on "QT"

 

[rt11002003]

Those numbers seem to indicate things are OK. Oil pressure keeps rising until rpm approaches max rated, at which time it remains constant. That is to be expected. The temp numbers also seem OK, especially considering you're talking about a couple of degrees difference on the high end. Most gauges can't even be read that precisely. I'd expect 10 to 15 degree temp rise in the early range of rpm rise and also when moving from cruise rpm to around 90% of max rated rpm.

Newer model engines run at higher temps than the older ones. My Yanmar in my 1987 Albin ran about 175 degrees at cruise and 190 degrees when advanced to about 3000 rpm, 80 to 90% of max rated rpm.

gene

 

[Levitation]

If it ain't clanging, banging, and smoking, it's fine...

 

[ttlmac]

There have been several threads in tugnuts on this topic. I have a 2010 R25 with the Yanmar 150 and get basically the same temperatures as you. I cruise alot in the low 3000 RPMs with the engine temp at 206 or 207. At WOT I am usually at 208. I have 175 hours on my engine without any problems at all. Also, I believe the engine alarm is 225, not 210.
Tom
Indian Summer

 

[D & C M]

Thanks Gene, denny-o and Tom you have reassured me, I especially liked denny's "mechanic's" quote. 🙂
Dave
"QT"

 

[JerryE]

Dave, u are wise to watch the temperatures. I have a Yanmar 4BY 150hp that was running 208-214 which I was told was "within specs." Actually that was high and was due to coolant leakage from my heater hoses, a problem Yanmar recently addressed by a huge recall. For me it caused long delays and missed time cruising until the temp finally got high enuf for folks to believe me; i.e., send out a Yanmar warrantee mechanic.

Your engine preheats at 77 deg with the coolant increasing to 86 deg. at what is called "post heating." Operating temp is 190 at beginning throttle opening and 205 at wide open throttle (WOT). If the ECU ( brain) detects higher coolant temps it will reduce engine power output. At 226 (or higher) the Yanmar display illuminates a warning, the Garmin declares "overheating" and an ear splitting alarm goes off until u turn off the engine. The maximum operating temp is 248 deg, but a Yanmar mechanic told me the ECU will not shut down the engine for overheating no matter the temp ever, cause u might be in a tight spot.

I'm sitting in Edgartown Harbor (80 degrees on Columbus Day weekend in New England-eat your hearts out Washintonians!) and I ran at 203-207 getting here in chop, but not exceeding 3000rpm. I'd agree with Tom that your numbers are where they should be. I'd add that no matter what anyone says keep an eye on Your temps and memorize your boat's ranges. I was right to be concerned even when others said my temps were "within specs." U should be around 205 when cruising under 3000 (I ranged 204-207) and around 205-208 over 3000 like Tom reports-although that will fluctuate a bit due to engine/boat/condition differences.