2003 Mack dump truck oil change intervals advice needed

We have a 2003 Mack tri axle dump truck.

387,500 miles or 19,800 hours on original engine.

Since I’ve now taken over servicing the entire fleet at our company (while also driving transport trucks), this truck has been an issue to me.

Every time I change the oil at 12,500 miles (700-1000 hours) the oil is like tar when it drains out.

I’ll change the filters, put 8 gallons (30 litres or so) of new oil in, start the truck, build oil pressure, shut it down, check the level....

Where’s the new oil? It looks like I haven’t changed it.

I spoke to my boss about it. I told him that maybe we should go by the hour meter instead of the odometer as the truck only averages 19.5 miles per hour stop and go.

We change all the oils in our construction
equipment at around 300-500 hours depending on which machine.

So far none of our machines make thick ugly looking oil when I drain them and they’re clean looking after a change.

I suggested we do like the machines, yes it’s almost double the oil changes but I don’t need a oil sample to tell me the oil is way past due.

I believe every machine is different, some can go a long time between changes and some cannot.

My boss’s son is like the devil on his other shoulder whispering in his ear not to listen to me. He said the oil is good quality and good for 12,500 miles no problem all of our trucks.

What happens? The boss listens to his son....

I installed a new turbo on this truck 3 years ago, and now there’s a brand new one on as of yesterday. Last one leaked oil into the intake.

Our 3406B Cat powered trucks went 33,500 miles between oil changes with no issues but they burn pretty clean.

So I’m wondering what would be the best way to clean up the engine to make it work better and keep the oil cleaner?

 

I’m sure if I can keep quiet, just change it, maybe it’ll start getting better.

If they asked why, I’ll tell them too bad.

While I have inframed a couple Cat engines, I’m not looking forward to inframing a mack.

 

Spsauerland: I’ll have to look into that.

I am not well versed in this engine as I am with the Cats we have.

But you are right. They’re absolutely gutless. We tried to see if a tuning guy could fix that but no luck.

Engine really has no power below 1,450 rpms. It’s also the worse on fuel economy out of the 3 dump trucks we have.

We have a 2003 Mack, 2005 sterling with Mercedes, and a1990 international with 3406B Cat.

The international will pass all of our dump trucks on the roads except on construction sites for maneuverability.

I didn’t know the Mack’s have egr. Can’t even see it. Our Mercedes powered dump truck has a egr cooler and valve at the front of the engine.

I know my 2005 freightliner with ACERT Cat uses IVA for egr.

Maybe that’s enough clues to which engine it is?

 

This is a Mack granite truck, 12 something litre engine, I think 400 some hp.

what cam would you recommend to fix this sooting the oil issue?

I do know that the large oil pan on the Mercedes does allow that engine to go a lot longer between oil changes but that’s a lot of oil.

 

Sounds like a crappy engine to work on.

the guy that drove it for 7 years I think has officially retired (I think).

It was hilarious when he jumped into the international (425hp 3406b cat) while his Mack was down for rear end repairs last year.

The guy that was always driving the international jumped into the sterling truck. (450 hp MBE4000)

(the speedo isn’t quite accurate in the international.)

The international takes off and leaves the sterling in dust.

I got told by the international driver that he’s always complaining that the Mack driver was always too slow, driving at 50-53 mph.

While in the international, the Mack driver is going 69 mph while thinking he’s actually going 56.

Speed limit around here is 50 mph..... lol!

International driver couldn’t believe it.

I’ll have to check into Rochester Diesel.

I’ll try and find the model of this Mack engine and we can see about going from there.