Do you use 15W40 , 10W30 , or even a lighter weight oil ?

Did you use it based on some's recommendation or what the owners manual stated ?

Not asking about Syn-oils , yet............

I have decided that I will probably start slowing switching all of my fluids out to synthetics. Just that piece of mind of having a fluid that will instantly flow is very reassuring. I understand that others have gone over 1 million miles on dino oil but I dont think they were in extreme low temps every single day like a few of us are.

 

 Thats the main reason I dont consider using it. I am very seldom in places that see the temps a lot of you see. Occasionally we will see temps in the teens, but it is unusual. Normal lows around me would normally be at or just below freezing. Just does not get that cold that often. This winter would be a bit of an exception however.

Synthetics also shine on the hot side when towing. I see a much bigger pressure drop pulling a grade with Dino vs Synthetic.

I cant say as I have ever noticed an oil pressure drop when pulling a grade in the summertime. But i am using the factory gauge and my looks at it are pretty quick and as long as it sitting about a 1/4" above the forty mark I figure it is good. A real gauge might show me something different. On top of that, I dont pull my trailer often. Probably 5 times a year, from one job to the next, sometimes home first. Never had any bad luck using dino. 

 I dont have anything against synthetic. I just have not had any issues thru the years using dino.

In your 02 I am not certain that it shows accurate pressure anyhow.

Thats where I was going whit the other post. Until I started hanging out here I had no Idea that the oil pressure gauge is mostly a dummy just letting you know you had pressure. Thats only a couple of steps ahead of an idiot light. I guess  could see the pressure start falling off well before the idiot light came on though. I dont watch it near as much DD'ing as I do when towing.

I am not 100% sure of operation on a 2002, but I do believe it is a glorified idiot light. On a 2003+, for sure, it has to see 0 psi for 30 seconds before the dash alarm goes off and the needle moves.

 

AFIK the late 2nd gens with the "updated" software are the same, only uses the transducer as a on/off switch.

It is not accurate on the 2002's for sure. Mine does the same as MoparMan's 

15-40 Rotella here.

 

 

I've heard from, the guys at my local cummins power systems shop that if you've been running conventional motor oil for the life of your truck, (or if you bought a used truck and the engine oil type history is unknown) then you should never switch to synthetic as it will cause seals to leak. 

It will not cause leaks, but it will clean the sludge off of the seals that may have been sealing the seals. It's because conventional oil doesn't clean the motor as well.

My truck had Delo 15w-40 run its entire life of 215,000 miles. Switched to 5w-40 full synthetic about a month ago and have driven over 4,000 miles since then. No leaks to speak of here.

My truck was also run on dino oil for the first 12 years of its life (about 67k miles worth). I switched to synthetic and have not developed any leaks. The engine is one of the cleanest I have ever owned, not even the slightest of leaks anywhere. Recently the power steering pump developed a slow leak, so I will be addressing it this spring.

I'll have too add that to my list

Old wives tails about oil. :banghead:

My 1998.5 Cummins has had 15-40 Rotella all It's life, with 202727 miles there have been no issues and she does not burn oil or smoke.

My 1998.5 Cummins has had 15-40 Rotella all It's life, with 202727 miles there have been no issues and she does not burn oil or smoke.

That is the way they are supposed to be as long as you take care of them, but if you were to start yours at -25* your truck would take quite a while building oil pressure. Synthetics will flow quite a bit easier at that temperature. This winter where I live we had 70 days so far this winter below zero (previous record was 59). With synthetics through out the drivetrain sure helped this year.

First couple of years I ran Rotella 15w-40. Then I retired and the wife and I started running the country visiting family and friends. Was visiting a friend in New York one winter and when I tried to start the truck, I did not like the sound or oil pressure. Went to 5w-40 full synthetic. Later found out during a call to Cummins, they sends out all their engines with Valvoline Full Synthetic and recommends using it. I use the 5w-40 year round because I never know where we might end up at, what season of the year it might be in and in what weather condition. Just service when due and go.

The 15w 40 is fine here temperature wise...but the smell when you come to a stop sign or red light is just nasty.

I switched from rotella to a hd irving brand 15w40 (its local) same smell. I added a couple feet to the puke hose.But I think I might have to go a bit further.

Regards Chris

The 15w 40 is fine here temperature wise...but the smell when you come to a stop sign or red light is just nasty.

I switched from rotella to a hd irving brand 15w40 (its local) same smell. I added a couple feet to the puke hose.But I think I might have to go a bit further.

Regards Chris

Have you seen this?? It would probably help/solve your problem smell wise.

 

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/26-engine-systems/42-crankcase-vent-mod

I had no Idea the vent mod was that good.

Thanks ever so much....doing my happy dance now, woo hoo.

Thanks 

 Chris

Ya. It is probably the easiest, cheapest and most effective mod that I have done to date. If you havent already your radiatior could probably use a good rinse out too.

I just watched the little movie.

His truck is identical to mine.

Mine is not that clean though.

I plan on doing that mod this weekend

Chris