Yanmar temp. UPDATE!!!

[micky692002]

My Yanmar engine is running at 180-185 degrees at 3000 rpm at it goes up to 190 at 3200. The thermostat opens completely at 171 degrees and its relatively new and the impeller is new too. Are these temps normal??

[mymojo]

Micky,
not sure if your Yanmar wwould be similar to my previous 6lp dte which ran at about 175 @ cruise of 3100 and typically rise to 185 when idling around. Have you checked the boatdiesel website?
Greg

[Anonymous]

My 240 Yaqn has only 80 hrs.
It runs about 140 to 160 degrees. At most speeds.
When trolling it just creeps up to 160.
Looked at owners manual. before sending this. There was no mention of running temps in book.

180 to190 seems high.

Len

[Anonymous]

I can't believe there hasn't been more discussion on the subject.

I know a retired engineer from Electric Boat in Groton , Ct who told me diesels should run about 140 ideally. 160 tops!!!

So when I read running temps of 180 and 190. Wow. Is this good for engine??!!

Any gurus out there? Rsvp!!

Len

[micky692002]

At 2950 rpm the temp is 187.

Next week I'm removing the thermostat to see what happens.

[Mistress]

Len...I'd have to disagree wholeheartedly. Diesels run better the hotter they are...to a point. There's an old saying: "the faster she goes, the hotter she gets, the faster she goes...."

My Dodge truck never sees less than 190. One of the hardest things on a diesel is running too cool (cylinder head temp). The carbon builds up and cretaes all sort of problems. That's why the big rigs all have cold weather fronts (the zipppered covers for the front grill). Granted cyl. head temp and water temp aren't the same, but related.

The only motors I know that like to run cool is raw water cooled gassers. Saltwater does funny things above 150. The salt crystalizes out of solution and plugs stuff up.

[micky692002]

I was just cheking my engine's book and it says that the opening temp of the thermostat is 167-174 F and the full open temperature of the thermostat is 194 F.

[Anonymous]

Just got off the phone with Yan dist in St. Pete, Fl. Nothing wrong with 160. Thinks my guage is off a little. Running over 190 is bordering on trouble.

Yes, you'll get a cleaner burn at higher temp, he says. Less smoke.

Len

[fisherofmen]

Micky,

How do you know the temps? Are you reading this from an analog guage? Do you have access to a temp gun so you could get actual temps? I don't trust analog guages.

Rick

[micky692002]

Rick I have a mechanical gauge in the boat and also have the laser thermometer. Both read the same temp.

In the pic the #1 is where the temp gauge is (on top of the water pump). If the temp there is 185 in #2 the temp is 165.

[fisherofmen]

Micky,

If you have a laser heat gun, then the temps are correct. Looks like your boat is eating belts. My Yanmar 190 used to do the same thing. It seems Like I was changing out the belt about every 150 hours.

Rick

[micky692002]

Rick, I have to tighten the belt every 2-3 times I use the boat.

[fisherofmen]

Micky,

I had a little surface rust on my pully. I used some steel wool and put it on the pully while it was running being careful not to get my fingers caught in the belt. It got all the rust off the pully and seemed to slow down the wear on the belt.

Rick

[skipm]

My Cummins has a 190 thermostat & thats what it runs at as long as the raw water screen is clean.

[micky692002]

Today I found the overheating problem. I took apart all the cooling system of the engine, heat exchanger, intercooler, turbo, air cooler. The impeller is in good condition, the heat exchanger was clean. When I took apart the intercooler, half of the fins (pathways) were clogged. That's one of the problems. The otherone was that both end caps of the heat exchanger have a round gasket with a division in the middle and that division was missing, maybe because of the years and that division separates the in and out of the water in the heat exchanger. If that division is missing cool water and hot water mixes so there is no cool water to cool the engine.

[Anonymous]

Has anyone talked to Yanmar and discussed running temp.

There has to be something sort of "official" on this, right?

I still run just under 160 and its a new engine with only 90 hrs.

Have had no problems. Should I anticipate any?

Len

[micky692002]

I talked to a Yanmar dealer and they told me my temp should be between 175-185 degrees