oil cooler hotter than any other part of the engine?

[The motor guy]

So the rest of the parts where oil is like the oil sump, oil filter etc, is at like 185 degrees, but hitting the oil cooler measured like 218 degrees after running an hour or so cutting an empty lot in 60 degree ambient temps. Why is the oil cooler so hot? Guess because it sends the hotter oil to the cooler to be cooled down? The cooler fins are dirty with dirt, so I guess I need to blow it out. Still thought it was odd though. This is a 25.5hp kawsaki fx801v 852cc engine

 

[DemoFly]

That would make logical sense. It gets heated and then sent there to be cooled.

 

[The motor guy]

That would make logical sense. It gets heated and then sent there to be cooled.

unless it's caked with dirt I guess lol

 

[MolaKule]

No, the combustion chamber and heads get hotter than the oil. A 5 second search showed this:

https://www.cycleworld.com/blogs/ask-kevin/how-critical-motorcycle-engine-parts-are-cooled/

 

[The motor guy]

No, the combustion chamber and heads get hotter than the oil. A 5 second search showed this:

https://www.cycleworld.com/blogs/ask-kevin/how-critical-motorcycle-engine-parts-are-cooled/

I just meant the areas where the oil is inside the engine. I worded it wrong

 

[johnmyster]

Piston cooling is sometimes a thing.

Generally, an oil pump pulls from the sump, forces oil through the filter and oil cooler before it is then fed into the various bearings/jets. As such, sump temperatures are generally higher than galley oil temperatures. Dry sump systems are an exception...

 

[Bottom_Feeder]

No, the combustion chamber and heads get hotter than the oil. A 5 second search showed this:

https://www.cycleworld.com/blogs/ask-kevin/how-critical-motorcycle-engine-parts-are-cooled/

Wow, I've never seen/heard Kevin Cameron talk before. His writing is brilliant.

 

[bullwinkle]

I just meant the areas where the oil is inside the engine. I worded it wrong

I bet turbocharger & rod bearings get warm, too; and underside of pistons (if an engine has piston cooling nozzles). I've heard of older diesel Mercedes running off oil cooling in an emergency, when the regular cooling system had a problem. Engine oil moves a LOT of heat!

 

[Brian123]

So the rest of the parts where oil is like the oil sump, oil filter etc, is at like 185 degrees, but hitting the oil cooler measured like 218 degrees after running an hour or so cutting an empty lot in 60 degree ambient temps. Why is the oil cooler so hot? Guess because it sends the hotter oil to the cooler to be cooled down? The cooler fins are dirty with dirt, so I guess I need to blow it out. Still thought it was odd though. This is a 25.5hp kawsaki fx801v 852cc engine

Your Engine is in the Rear and not the front of the Mower, so it will run hotter. Kind of the reason Kohler got with Amsoil 2 design a 10W-50 motor oil. Whether this is a Kohler or Kawasaki, we are talking air cooled. Here is what you need to do, forget about the Infrared Gun because it is not accurate. I got myself a thermometer temp probe that I take the dipstick off after mowing and get my temp reading.

With the Infrared Gun the Oil Temp means nothing since you are taking a temp of the oil filter housing, same thing with taking a temp near the oil drain plug. You are taking a temp of the metal and not the oil. I bought a thermometer that was like $8.00 from Amazon, and it has been a great help.

My other thought here is to make sure you blow this mower off after each use, everything on this Engine needs to be free of debris and dirt. Take like 2 minutes or less after each time you mow the yard to just blow everything off your mower, this means the whole mower and not just the engine. Blow between the deck and engine!

I leave my Mower running for a minute while I go get the blower and blow the machine off, and then I put it in the shed and turn it off.

Why is your oil cooler so hot? You said the cooler fins are dirty, so like you said, you need to clean it up.

I want to point something out again about blowing everything off after each mowing, or if the machine is used commercially, after each mowing. This is an air-cooled engine, it needs to be blown off, after each mowing.

 

[RazorsEdge]

Your Engine is in the Rear and not the front of the Mower, so it will run hotter. Kind of the reason Kohler got with Amsoil 2 design a 10W-50 motor oil. Whether this is a Kohler or Kawasaki, we are talking air cooled. Here is what you need to do, forget about the Infrared Gun because it is not accurate. I got myself a thermometer temp probe that I take the dipstick off after mowing and get my temp reading.

With the Infrared Gun the Oil Temp means nothing since you are taking a temp of the oil filter housing, same thing with taking a temp near the oil drain plug. You are taking a temp of the metal and not the oil. I bought a thermometer that was like $8.00 from Amazon, and it has been a great help.

My other thought here is to make sure you blow this mower off after each use, everything on this Engine needs to be free of debris and dirt. Take like 2 minutes or less after each time you mow the yard to just blow everything off your mower, this means the whole mower and not just the engine. Blow between the deck and engine!

I leave my Mower running for a minute while I go get the blower and blow the machine off, and then I put it in the shed and turn it off.

Why is your oil cooler so hot? You said the cooler fins are dirty, so like you said, you need to clean it up.

I want to point something out again about blowing everything off after each mowing, or if the machine is used commercially, after each mowing. This is an air-cooled engine, it needs to be blown off, after each mowing.

I do this every time. Also I've heard of garage fires from grass being left on the mower and catching fire.

 

[ripcord]

If you are comparing the temps with a heat gun type thermometer, you should know that they are not the most accurate. The texture and reflectivity of the surfaces you're measuring have a big impact on their readings. 50f errors are totally within the range of possibility. The most accurate way to check is to use a K-couple type thermometer.

 

[The motor guy]

I bet turbocharger & rod bearings get warm, too; and underside of pistons (if an engine has piston cooling nozzles). I've heard of older diesel Mercedes running off oil cooling in an emergency, when the regular cooling system had a problem. Engine oil moves a LOT of heat!

It might, but I think that's more of a diesel thing.

 

[burbguy82]

So the rest of the parts where oil is like the oil sump, oil filter etc, is at like 185 degrees, but hitting the oil cooler measured like 218 degrees after running an hour or so cutting an empty lot in 60 degree ambient temps. Why is the oil cooler so hot? Guess because it sends the hotter oil to the cooler to be cooled down? The cooler fins are dirty with dirt, so I guess I need to blow it out. Still thought it was odd though. This is a 25.5hp kawsaki fx801v 852cc engine

There is a spot in the engine, lubricated, that is hotter than the 218 you posted.

By the time the oil gets to the cooler, it would have to cool down some, even if a "small" amount.

 

[ripcord]

So the rest of the parts where oil is like the oil sump, oil filter etc, is at like 185 degrees, but hitting the oil cooler measured like 218 degrees after running an hour or so cutting an empty lot in 60 degree ambient temps. Why is the oil cooler so hot? Guess because it sends the hotter oil to the cooler to be cooled down? The cooler fins are dirty with dirt, so I guess I need to blow it out. Still thought it was odd though. This is a 25.5hp kawsaki fx801v 852cc engine

It depends on the path oil follows through the oiling system. If the cooler is the last thing in line, i.e. after the bearings, then it is going to be hotter than the sump temps (being compressed by the bearings causes heat). The oil in the sump is down stream from the cooler so would have the benefit of being cooled by the cooler and therefore have a lower temp than at the cooler.

 

[Opelman]

The cooler is not going to be after the bearings. Most mower engines have the oil cooler plumbed before or after the oil filter. Next time I am at work I'll check the plumbing for flow. My instinct tells me after the filter.

 

[The motor guy]

The cooler is not going to be after the bearings. Most mower engines have the oil cooler plumbed before or after the oil filter. Next time I am at work I'll check the plumbing for flow. My instinct tells me after the filter.

I'll have to look. It has hoses coming from the filter housing. The filter was like 185 when I measured. Same with the valve cover.

 

[The motor guy]

I think it goes through the cooler, then the filter becaise the filter was 185

 

[The motor guy]

Both those hoses 90 out of the filter head

 

[Opelman]

Both those hoses 90 out of the filter head

I'll follow the oil path when I go back to work. We have several brands to choose from, Briggs, Kawasaki, Yamaha, and Kohler. My thought is that I would want the filter first to help prevent the cooler from plugging up internally.

 

[burbguy82]

did you add this cooler?