Kubota, Rotella, and engine temp

[oledocward]

I'm getting ready to change the engine oil in my Bx2350. It was new last year and I'm assuming came with Kubota 10W30 oil. And after the 50 hr service, again with Kubota 10W30, the water temp consistently ran above normal all summer and the rest of the year with extended use. I've read a thread or two here which stated that by switching to Rotella 15W40, the engine temps ran lower than with 10W30. I've done a half dozen searches and have seen the cooler running temps with 15W40 observation only a couple of times.

My question is--should I switch to Rotella or continue with the Kubota oil--if engine temp is an issue?

By the way, my dealer said that the reason my tractor ran on the warm side was because of the location of the temp sensor relative to the radiator. Anyone heard of this?

tractoring in North Carolina, oledocward

 

[pdowling1]

I doubt that two different oils of similar viscosity will cause a difference in operating temp. More likely your radiator, or prescreen os obstructed with dust/dirt. Until you exceed the capacity of your cooling system, the operating temp is determined by your thermostat. If the oil is really causing you to run hot, it would mean it wasn't lubricating adequately, in which case your engine wouldn't last very long. I use Rotella myself in my BX2200. It only runs hot when the screen becomes clogged with dust & it's under heavy load. I just clean the screen & the temp immediately falls back to where it belongs. The screen & radiator tend to plug up quickly when mowing in dry conditions.

 

[drtydeed]

Can't answer for sure about the temp thing, mine never runs hot (and I've always run Rotella 15/40). The tech that dropped off my machine crossed out the spec in the owners manual and wrote in 15/40. You may want to check over in the O&L forums.

 

[Skyco]

Until you exceed the capacity of your cooling system, the operating temp is determined by your thermostat.

Exactly right. The oil has almost nothing to do with your operating temperature, something else is going on....

 

[Volfandt]

Likes been said, a clogged or partially clogged intake screen is the primary cause for a BX (or any tractor for that matter) to overheat. I can see immediate temp gauge deflection to the cooler side once I swipe the screen clean.

As to the oil, yes the oil does effect engine temp., but not to the degree of reduced air flow through a radiator and/or through the engine cowlings of an air cooled engine. Course this is more relevent to air cooled engines but it is still applicable somewhat to liquid cooled engines.
In liquid cooled engines the oil is cooled somewhat by having as large of an oil sump (oil pan) as the engine can have and still fit in it's compartment whereas high performance liquid and air cooled engines add external oil coolers. I added a thermostatically controlled oil cooler to my former Harley Davidson. The benefit of having it thermostatically controlled allows the cool oil to bypass the cooler which gets it up to operating temperature quicker. It was advertised as an addon to help keep the engine from overheating by cooling the oil. Later model models added these coolers as OEM, so they must have worked pretty good in helping to keep the engine(s) from overheating.

I don't know if 15w40 will cool any better than 10w30 and it won't hurt to try it. You're only talking about the cost of 4 qts of oil and a filter

 

[oledocward]

The first thing I did was clean the radiator screen and made sure there was nothing blocking the air flow around the radiator--and cleaned it over and over, even when it was not dirty. Still runs above normal, about half way between normal and hot. The dealer says nothing is wrong, just the location of the temp sensor. Maybe he's right, maybe my tractor just runs warm. I don't know.

Does the BX have a replaceable thermostat. I can't find it listed as a part anywhere.

 

[big bubba]

Could be a temp sensor related issue, would be good to get an actual degree reading with a high temp thermometer. perhaps at operating temp place a towel over the cap and SLOWLY open cap (some coolant loss) then take a direct reading. BE CAREFUL bb

 

[big bubba]

Naturally check coolant temp w/engine off. what about defective thermostat....these things seem unlikely (but possible) with a new tractor. even if you clean the radiator screen, also be sure to see that the radiator fins are clear. blow them out with low pressure from engine side out. surely the radiator itself is not restricted being that new? worth a flush?

 

[mozark]

From the posts I've read on here, I suspect a lot of the problem is a wide variance in temp gauges and sensors (why else wouldn't they put numbers on the temp gauge). Because of that, I bought a infrared thermometer to watch the temp on mine, the hottest I ever got it was on a 95 degree day, mowing hard. The temp gauge was getting close to the red when I checked it and the engine was 204 degrees and the hydrostatic was 185. I don't have a clue as to what temperature is considered "overheated", but I'm guessing that anything under 230 with an antifreeze/water mix is ok.

 

[Reg]

IF you have a problem changing to an oil that reduces or masks it would be a marginal solution at best. I would check the thermostat first, just put it in a pan of water on the stove. Auto thermostats tend to either fail open or open at lower temperatures as they age.
If that is OK, maybe the water pump - IF there is a real problem.
After that I guess just throw parts at it, starting with the temp sensor.

OTOH, I wouldn't buy a KooBooBoo anyway (-:

 

[Sully2]

Since most tractor ( and auto for that matter) gauges are semi "funky" I'd get a REAL GAUGE and hook it up and see exactly what the temp ACTUALLY is.

If the temp is actually running HIGH...termostat would be changed first...and if you like Rotella..as I do...Id go with the 5W-40 syn..which I did and Im glad I did.

 

[oledocward]

Thanks to all for good, sage advise; I think I will switch to the Rotella, just for the convenience and satisfaction most of the folks here have had with it.

And I will check the engine temp with a laser thermometer. I probably just worry too much because the tractor is almost new.

Does anyone know if the BX tractors have a replaceable thermostat? That was the next thing I was going to check after cleaning the radiator, screen, etc., but could not find a thermostat listed as a part anywhere.

Thanks, again to all.
oledocward

 

[Lockport]

I doubt that two different oils of similar viscosity will cause a difference in operating temp. More likely your radiator, or prescreen os obstructed with dust/dirt. Until you exceed the capacity of your cooling system, the operating temp is determined by your thermostat. If the oil is really causing you to run hot, it would mean it wasn't lubricating adequately, in which case your engine wouldn't last very long. I use Rotella myself in my BX2200. It only runs hot when the screen becomes clogged with dust & it's under heavy load. I just clean the screen & the temp immediately falls back to where it belongs. The screen & radiator tend to plug up quickly when mowing in dry conditions.

Absolutely! The screen behind the rad is dirty. Careful of the foam strip when pulling it out. It tears easy but can be glued. If it is already torn, then there is probably a lot of fine dust on your rad behind that screen (IE removed) behind the battery and compressed air or a small hand brush will get it off. I had the same problem last year. It ran hot all the time, which I discovered after discovering the temp wire had come off the sensor and that is why it would never warm up. Kept adding coolant too! Glad I never hurt anything.

 

[Volfandt]

Yes, BX engines have thermostats. They are located in the goodeneck where the upper radiator hose attaches to the engine and it is rated @ 180 degrees.