Dd15 maintenance questions

[Ballerxl]

Hey guys I have a 2020 Freightliner 122sd 39122 miles dd15 14.8 L
Questions are is there a certain type of oil I put in and is there any precautions I need to consider when changing oil and fuel filters? And can I put gear oil in with I’m changing oil? I did that with my Cummins engine but I don’t know about the Detroit engines.. I’m trying to learn everything about this engine to keep it running good for a while

[JimT]

don't own one of those, but gear oil isn't recommended if the engine is burning oil and the DPF is intact as it will leave a lot of ash. Not sure the recommendation for engines with aftertreatment that don't burn oil.

Rawze's thread on gear lube:
Why I add 12% (one gallon) of gear lube at every oil change...

As for type and when to change oil, regular old conventional oil is the way to go, unless you're in an extreme cold weather application then synthetic will help with cold starts. As for brand, most guys recommend Rotella though any major name brand oil found at truck stops should be fine. Best to pick one and stick with it, which is why ease of availability is a factor.

Don't bother with oil or fuel additives unless you are treating a specific condition such as microbial growth in the fuel with a biocide. The so-called performance boosting additives rarely produce measurable benefits while costing a lot more then any maintenance they claim to prevent.

Oil change interval should be based on average fuel mileage during that oil's life.

ISX and Bypass Oil Filter Systems:

(03-01-2016 )Rawze Wrote:  Here is what I would recommend to others based on what I have seen..

If your average fuel mileage every 10,000 miles is ...

less than 5 MG -- Change your oil every 8,000 miles or so.

5 - 6 MPG -- Change your oil every 10,000 - 12,000 miles or so.

6 - 7 MPG -- Change your oil every 12,000 - 15,000 miles or so.

7 - 8 MPG -- Change your oil every 15,000 - 18,000 miles or so.

8 - 9 MPG -- Change your oil every 18,000 - 22,000 miles or so.

above 9 MPG -- Change your oil every 22,000 - 28,000 miles or so.

I did a little adjustment to the above numbers to come up with this simple calculation for my fuel mileage spreadsheet so I can easily track when my new oil change should be in real time with each fuel up:

Code:

Next Change = Previous change odometer + ((Average fuel mileage this oil - 2) * 3000)

For example:
Previous oil change: 586,296mi
Average Fuel Mileage since last oil change: 7.275mpg
586,296 + (( 7.275 -2) * 3000) = 602,120mi or about 15,824mi for that fuel mileage.

I use that calculation as a target for scheduling my next oil change. The above calculation changes Rawze's chart to look like this (Note that on the high and low ends of MPG my calculation is a bit conservative favoring slightly shorter intervals):

Code:

3 mpg --------> 3000 mi
4 mpg --------> 6000 mi
5 mpg --------> 9000 mi
6 mpg --------> 12,000 mi
7 mpg --------> 15,000 mi
8 mpg --------> 18,000 mi
9 mpg --------> 21,000 mi
10 mpg -------> 24,000 mi
11 mpg -------> 27,000 mi

values between intervals easily computed via simple equation:
( AVG MPG - 2 ) * 3000

For EGR enabled engines a bypass oil filter (an inexpensive Amsoil unit is typically recommended by people here) will greatly help reduce soot buildup in the oil but it shouldn't be used as a tool to extend oil drain intervals.

Personally I always change fuel filter with the oil. Fuel/water separator in mine is a Davco with the clear plastic housing so I change that according to it's level. If your freightliner has a different setup for fuel/water sep then you will need to follow different guidelines.

As for filter brands, I usually stick to the Fleetguard brand. Available almost everywhere and usually the most cost effective.

While the info on this site is geared toward Cummins engines the basic points of an EGR Tune-up are the same and will be one of the best tools to maximize engine and aftertreatment life and minimize down time.

[Rawze]

I can't find the TSB's on it but DD's have an inherent problem as they age where is says something about never changing the fuel filter and oil + oil filters all at the same time. Big lawsuits have been made over this in the past against oil change places who do the typical drop the oil, all the filters including fuel, dacvo if there is one, etc.. all at the same time .. put new oil in, put new filters back on and then crank it up. That extra delay in firing off due to fuel pressure lag + the oil pressure not up to snuff yet = known issue being high chance of spinning a main bearing and destroying the crank/engine. It can do this even if they pre-fill the filters.


So....

Always ensure whenever the oil is replaced... change the oil and oil filter only ... crank it up and let the oil pressure build back up good before going any further. Then change the fuel filter separately. Otherwise, the older the engine gets, the higher chance of it loosing a bearing.

=====================

here is another FYI:

dd15's ... The starter is on the exhaust side of the engine... below the hot exhaust piping. - i can;t tell you how many people that I have met, were totally stranded at a truck stop fuel island with their DD's not wanting to crank. They call a tow-truck because no matter what they do it will not crank ... just some faint clicking maybe. Half an hour or so later, by the time the tow-truck arrives .... engine fires right off again without any issue. There is never any faults or codes in the dash... nothing. it simply leaves you stranded.. and it is a common issue.

- The reason it happens is that someone is pulling a hill and exhaust is really hot... or it went into regen or some other thing that got the exhaust real hot. The driver pulls off the freeway and into a fuel island.. and shuts truck off and exhaust is still quite hot. - All that heat bleeds into the exhaust side of engine and block and it trips the starter over-temp sensor.. and the thing will refuse to crank until the whole thing cools off, sometimes 20 - 30 minutes later or more.

Just an FYI: Seen several people with my own eyes this happened to ... Pour several gallons of water on the exhaust side of the engine block and around/onto the starter to cool it off ... and it fires up again... no need for a tow-truck. - I also then remind them to always let the engine and its exhaust cool off for several minutes before shutting engine down and it will prevent it.

[Ballerxl]

Cool thanks for a lot of the info and I’ll definitely keep the starter in mind .. I live in west Texas so it’s mostly hot here .. but I will separate my oil and fuel changes when it’s time.. so I’m guessing I don’t have to fill my oil filter cartridge with oil and can just place the filter inside and put the cap on it? I’m used to the Cummins and I would fill my oil filter before I put it on.. so I’m researching all I can about this engine and I know here I would find very helpful info as y’all have helped me before so I appreciate it guys

[Rawze]

(01-24-2021 )Ballerxl Wrote:  Cool thanks for a lot of the info and I’ll definitely keep the starter in mind .. I live in west Texas so it’s mostly hot here .. but I will separate my oil and fuel changes when it’s time.. so I’m guessing I don’t have to fill my oil filter cartridge with oil and can just place the filter inside and put the cap on it? I’m used to the Cummins and I would fill my oil filter before I put it on.. so I’m researching all I can about this engine and I know here I would find very helpful info as y’all have helped me before so I appreciate it guys

I would suggest you change your oil/filter as recommended by the engine maker, however they say to do it.