Community Forums

**pasdad1** · 03-02-2020, 09:30 AM

Quote:

Originally Posted by jimmy braden

Only if oil temps are near the 200 degree range. Most the time its closer to 180 at most. My pre tier4 engine doesnt get coolant temps over 183 normally.

But yes, there is moisture, the question is when does it bc problematic.

Oil temperature is usually much hotter than coolant temperature.....especially when it is circulating around the crank bearings, rod bearings, etc. If you measured in the sump, then you are measuring the temp of the oil after it has already cooled some (which is the point of the big oil pan and gallons of oil). Pretty much guarantee the oil has reached temps of 200+ at some point in its travels through the engine.

Jon_C · 03-02-2020, 12:07 PM

Is there a diesel motor failure epidemic in this country from folks not changing oil yearly? If so I haven’t heard about it, but maybe you have?

Steve578 · 03-02-2020, 12:42 PM

It's cheap insurance to change the oil every year, even with low miles. I would not change the fuel filter until the computer on the dash says so or when the recommended interval is reached.

bentjm · 03-02-2020, 02:03 PM

If you bought a new coach that had been sitting on the dealer lot for a year, would you have them change the oil as part of the purchase?

Monacoach · 03-02-2020, 03:43 PM

Quote:

Originally Posted by Piros1

Then why would you think it is OK to go 3 years if your manual states 15,000 miles or one year? Either is the maximum and hot the minimum.

The one line printed in the manual applies to us all regardless of idling time, miles, type of driving, climate.
Its a wide brush and subject to interpretation and adjustment. The manual is not my only source of information. You feel differently and that is fine

Parkers2ca · 03-02-2020, 03:49 PM

The only enemy to your oil and engine while parked would be condensation. If you live in a climate where the seasons, and storage facility, can leave your vehicle sweating ,then the inside of that engine sweats too. If you start it up briefly during storage your not helping that condensation issue (because the engine would really need to reach operating temp. to burn that off). So, if your high and dry you'll be fine. If you suspect condensation (water), then I'd change oil and filter.

jimmy braden · 03-02-2020, 04:27 PM

Quote:

Originally Posted by pasdad1

Oil temperature is usually much hotter than coolant temperature.....especially when it is circulating around the crank bearings, rod bearings, etc. If you measured in the sump, then you are measuring the temp of the oil after it has already cooled some (which is the point of the big oil pan and gallons of oil). Pretty much guarantee the oil has reached temps of 200+ at some point in its travels through the engine.

most cummins have oil coolers. I can tell you mine is not anywhere near 200. Iv pulled the dipstick and its not that hot after several hours.

jimmy braden · 03-02-2020, 04:34 PM

Quote:

Originally Posted by pasdad1

Oil temperature is usually much hotter than coolant temperature.....especially when it is circulating around the crank bearings, rod bearings, etc. If you measured in the sump, then you are measuring the temp of the oil after it has already cooled some (which is the point of the big oil pan and gallons of oil). Pretty much guarantee the oil has reached temps of 200+ at some point in its travels through the engine.

you might be right but most cummins have oil coolers. So, that being the case, it would stand to reason a good 45 min run with turbo at full load should heat it up enough.

maybe,.

Sundancer268 · 03-02-2020, 04:42 PM

Quote:

Originally Posted by jimmy braden

you might be right but most cummins have oil coolers. So, that being the case, it would stand to reason a good 45 min run with turbo at full load should heat it up enough.

maybe,.

You are right, the sump temp is lower, the critical heat is generated on the cylinder walls and bearings on the cam and crankshaft, here the heat generated will be hot enough to remove any water in the oil. The cooler is used to keep the oil going to these critical parts low enough so the additional heat generated there will not cause the oil to break down in those critical areas. The oil pan also acts as an oil cooler with the large surface area of the pan and the large quantity of oil held there.

Monacoach · 03-02-2020, 04:49 PM

So when does condensation occur? After one year? All the time? If it is an everyday occurrence i dont understand the change oil connection.......it seems as others have stated that condensation burns off while driving.??....

jimmy braden · 03-02-2020, 04:52 PM

The only problem there is that means a conventional oil might be approaching the thermal limits and it really not be reflected at any measurable level. And since some of these newer motors have to have LOW SAPs (https://www.bobistheoilguy.com/forum...:_ACEA_warning ) to keep from fouling DPFs, it still is a possibility that the oil will be experiencing a loss of viscosity for some of the engines with lots of emission controls.

Im not to worried,, my oil analysis shows rock solid after multiple samples..

Quote:

Originally Posted by Monacoach

So when does condensation occur? After one year? All the time? If it is an everyday occurrence i dont understand the change oil connection.......it seems as others have stated that condensation burns off while driving.??....

It begins the second you shut it off..

You have to decide if thats a risk you need to address.

gelliott · 03-02-2020, 04:59 PM

Oil and filters are cheap, relatively speaking. If it has been a year I would change the oil. Why not.

Monacoach · 03-02-2020, 05:09 PM

Quote:

Originally Posted by gelliott

Oil and filters are cheap, relatively speaking. If it has been a year I would change the oil. Why not.

2.5 years actually

Monacoach · 03-02-2020, 05:20 PM

Quote:

Originally Posted by jimmy braden

The only problem there is that means a conventional oil might be approaching the thermal limits and it really not be reflected at any measurable level. And since some of these newer motors have to have LOW SAPs (https://www.bobistheoilguy.com/forum...:_ACEA_warning ) to keep from fouling DPFs, it still is a possibility that the oil will be experiencing a loss of viscosity for some of the engines with lots of emission controls.

Im not to worried,, my oil analysis shows rock solid after multiple samples..

It begins the second you shut it off..

You have to decide if thats a risk you need to address.

So based on condensation alone when does changing the oil eliminate the risk.... just trying to wrap my head around this condensation and one year connection.....does condensation become rampant after one year? Does driving the coach not burn off condensation? If so i would think you could use the same oil for a hundred years and have the same condensation so long as you drive the coach? Just referring to condensation at the moment....