Abused oil... an analysis I bet some would like to see

[Forkman]

I was just thinking about this. Can't believe I didn't mention this before. At the prison I work at we have a perimeter vehicle that circles the prison 24/7 (when its not in for repairs) at no more than about 20mph and less than 1000RPM on average for engine speed. The vehicle is a 2003 Dodge Ram Cummings Turbo Diesel... the oil is changed every 3K and one lap around the perimeter is about .7 miles.

I'd love to see an analysis of this oil... anyone else care to take a stab at what kind of problems we'd see in an sample of this oil?

 

[Audi Junkie]

Without multiple cold-starts, the oil is not really stressed. It is probally a HDEO 15w-40 anyway. It would be best if it were rung-out once in awhile though.

 

[Jelly]

Never heard of a Cummings...hmmm, much be some sort of super-duper unlisted special option or something?

[ April 27, 2004, 12:39 AM: Message edited by: Jelly ]

 

[seotaji]

cummings are pretty much te best diesels you can get, too bad they're in a dodge.

they give great results when boost is increased.

 

[jthorner]

That sounds like easy duty for the truck to me. Moderate speeds, yet on long enough to get up to full operating temperature.

3,000 mile OCI on a diesel rated oil should be no problem.

 

[Neil Womack]

Can you get a sample?

I think you will get high wear numbers in iron & chromium with fuel dilution of the oil.

Both due to wash down of the cylinder walls. This is like a continuous idle condition.

If my math is correct you change the oil every 100 day after 2400 hours of operation. Only analysis will tell. However, my guess is that way to long a change interval.

[ April 27, 2004, 03:58 AM: Message edited by: Neil Womack ]

 

[Jelly]

quote:

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Originally posted by carrera79:
I'll put a Duramax up against the Cummins any day.

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I must say, the Duramax has exceeded my expectations from day one. I was born and raised around semis and I6 engines, and a V8, aluminum-head diesel was foreign to me...I said a lot of bad things about the Duramax that I just shouldn't have said.

The newly redesigned Duramax is even more impressive and I'd have no problems recommending it to anyone.

In comparison to the ISB though, they are two totally different engines, that in reality, although they are put in the same size vehicles, were actually designed for two entirely different applications.

First off, the Duramax is a light duty engine and the Cummins is a medium duty engine.

The Cummins will last longer and the Cummins can put much more power to the ground before giving up the ghost...

 

[Jelly]

quote:

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Originally posted by Chris B.:
Diesels are ment to idle. Look at all the semi's that idle al night long when the dirver sleeps. I bet it would be ok.

---

Chris,

Diesels aren't meant for idling by any stretch of the imagination...they're just better at it that they're gas counterparts because of no air restriction at idle, thus consuming a much lower amount of fuel when at a dead idle.

BTW, most drivers don't idle all night long either. Unless it's very cold or very hot, you'll hardly see it because its simply a waste of fuel and increases engine wear. More and more drivers are becoming aware of this and actually doing it as fuel prices continue to rise.

Wanna hear something funny? A few fleets actually now will SLOW YOUR TRUCK DOWN if you idle for too long! If you're idling time is over a certain percentage of total operating time, max road speed is derated to 68mph instead of 72. This isn't done by a aftermarket computer either...this option is already in the ISX PCM.

 

[pezzy669]

I was always told it is bad to idle diesels or any turbo/super charged vehicle for that matter.

From what I understand the piston rings on forced induction engines require some turbo/super charger pressure to seal properly. So at idle the rings are not sealing completely, there is more blowby, less efficient combustion, and more fuel getting into the oil.

Please correct me if I am wrong.

 

[Pitbull]

quote:

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Originally posted by carrera79:
I'll put a Duramax up against the Cummins any day.

---

It's pronounced duracrap'

 

[G-MAN]

quote:

---

Originally posted by pezzy669:
I was always told it is bad to idle diesels or any turbo/super charged vehicle for that matter.

From what I understand the piston rings on forced induction engines require some turbo/super charger pressure to seal properly. So at idle the rings are not sealing completely, there is more blowby, less efficient combustion, and more fuel getting into the oil.

Please correct me if I am wrong.

---

The compression ratio on even a non-turbo diesel is roughly two to three times what it is on a typical gasoline engine. Turbo pressure to seat rings would therefore be a non-issue. AFWIW, I've never heard of this before anyway.

 

[Forkman]

Something else to consider is the abuse the cooling system is taking, since it never gets moving fast enough to move a decent amount of air through the radiator.

The electronics on the truck are constantly failing. Its always going in for an ABS/Brake light coming on, or the airbag light. The headlights were blowing too about once per week until the dealership disconnected the DRL feature.

 

[Bio-T]

quote:

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Originally posted by Pitbull:

quote:

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Originally posted by carrera79:
I'll put a Duramax up against the Cummins any day.

---

It's pronounced duracrap'

---

No engine brand wars please. I will take any one of the three, Cummins, International or Duramax. He who has the best price, gets my business. The rest is just bragging rights.

 

[ekpolk]

quote:

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Originally posted by Forkman:
The electronics on the truck are constantly failing. Its always going in for an ABS/Brake light coming on, or the airbag light. The headlights were blowing too about once per week until the dealership disconnected the DRL feature.

---

Well Forkman, let's be optimistic. As you said, this vehicle is used to patrol the perimeter of a prison. Any person who might reasonably be expected to be found in the path of this truck is either: 1) if outbound, an escaping felon or 2) if inbound, probably assisting someone from the first category. For the good of society, both need to be shot or just run over. So who cares about the ABS anyway?

 

[dustyjoe1]

I agree that is probably too long and oci

 

[G-MAN]

quote:

---

Originally posted by Neil Womack:
I think you will get high wear numbers in iron & chromium with fuel dilution of the oil.

Both due to wash down of the cylinder walls. This is like a continuous idle condition.

---

Not with a diesel.

 

[Jelly]

Wet stacking anyone...

 

[carrera79]

I'll put a Duramax up against the Cummins any day.

 

[Chris B.]

Diesels are ment to idle. Look at all the semi's that idle al night long when the dirver sleeps. I bet it would be ok.