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?
2003 Mack dump truck oil change intervals advice needed
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Oil turning black instantly isn't a sign of bad oil or something wrong. This pretty typical. Oil is designed to pick up and hold carbon/soot deposits. Most older engines are like this. Being like tar and very very sooty at change time is a for sure sign it is being used too long. Trucks like a dump truck don't see many highway miles and idle a lot or stop and go a lot which is hard on everything. Most rules of thumb point engines with less than about 5.5 mpg to be severe service therefore fall under lower change intervals. End of the day, oil is cheaper than an overhaul. Change oil, not engine. Try changing the oil a hundred hours earlier and see how it looks.
2003, is it an ETECH or ASET motor. The ASET AI or AMI they used in vocational trucks has internal EGR (massive valve overlap) . It soots the oil pretty good. I think in 04 Mack updated the oil pan to a 55 qt to increase OCI. Thank goodness, but we no longer run any everyday. They are actually pretty dependable, just absolutely gutless. Not designed to operate much below 1450 RPM at all. Overhauled 2, and I think put cams in all we had (all bought used during recession, so previous maintenance was non-existent). Swung longblock in one also. Not bad to overhauled, but standard liner puller doesn't work. They stay tight the whole ride out of the block.
We changed oil on 10,000 mile intervals. Soot was always higher than comparable engines until we put cams in them. ASET AC was external EGR with better cam if you catch my drift.
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?
Sounds like an ASET AI motor. We ran primarily 427's, but had one 460 with a smoke file and it ran okay. Our T800's dumps with 335/1550 high torque rise C13's would eat the Mack's alive and the KW's had 4.33 and Mack's had 4.42 gears. I think Rochester diesel does offer some performance improvements. Some folks got so frustrated with them they converted them to E-TECH motors. A bigger oil pan or shorter OCI is a must if keeping same camshaft. Oil pan is over 2 grand USD through Mack, found stainless oil pan through B and H tubes for around $1200.SAR Thanks this.
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.
Mack ASET AC 460 cam if keeping as ASET, E-TECH if converting back CCRS E-TECH. I think Rochester diesel has injector nozzle options for power increase, but the EPA tuning kills any performance in those dogs.
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.spsauerland Thanks this.
Hold on a sec and ill post a link to bmt forum where a guy converted his ami 370 to a plain ole E-tech. Just seeing the manifold size difference will tell you everything you need to know.
The 460XT file was 487hp/1760tq out of a 11.9L (728 cu) they can be made into monsters. A 3406 has a 6.5 stroke and 5.4 bore. The E-7 also has a 6.5 stroke 4 7/8 bore. The E-7 has buttress bolts as well.
Give me a few ill post the link. Very informative read
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