Everything Wrong with the Cummins 6CT 8.3L

Sure, it's heavy as hell, but it's pretty dang reliable, easy to rebuild, the p-pump models are easy to tune and get more power out of, and for applications like motorhomes and busses, you're more likely to see the vehicle break down and fall apart well before the engine fails.

For medium-duty applications, it's a pretty solid engine with decent power output compared to comparable engines from other companies like Cat and International.

But, because of its hefty weight, it's a bad candidate for swapping into anything like a 1500 or 2500 truck, although it can and has been done before.

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[Dustrunnersauto]

What do you think? Good engine or overrated?

[laladilky]

I drove a mobile Lube truck with the 8.3 36, 000lbs bed all over and serviced with it, never turning off idling and running for anywhere from 8-14 hours a day. Never had a single issue! The truck currently has over 38, 000 hours and it’s still a one of the most reliable in the fleet. Will always be a fan.

[lamarzimmermanmennonitefar]

I'm an International Harvester diehard, but I'd say farmers in my area very much prefer the 5.9 and 8.3 Cummins. Reliability and fuel efficiency are usually mentioned. I'm sure it helps a lot that the Cummins tractors had powershift and nice creature comforts!

[bladenrexroth]

Uncle p pumped his ISC after the CAPS went out. I helped him put on a compound Switzer(whistler) over HX55 turbo with an air 2 air inter and after cooler. Truck is easily putting down 450hp/1300tq. He's had it 10 years and we rebuilt it last February. Says it has better performance than his stock ISM310 and get almost 5 mpg better. Almost 17 mpg loaded to 50k#'s

[lamarzimmermanmennonitefar]

Cavitation is just a maintenance issue. The International 300 and 400 series had the same problem as well which is why International introduced the field service kit with the water filter with pelletized coolant conditioner.

[lllateralus]

My old 2003 Alpine Coach diesel pusher has the CAPS ISC 8.3, 116K miles and runs like new. a few oz of 2 stroke oil every fueling keeps the pumps lubricated and problem free. Mine has the old Banks Power Pack kit (Ottomind fuel controller, wastegate, gauges) and is rated at 440 HP and 1200 ft lbs. GREAT engine. 30 pounds of boost all day.

[mayberickcanfixit]

Deboss Garage has a pretty good explanation on the 8.3 in the combines. Its something to do with the thermostat housing, to fit the machine it needed to be modified but it starves the block of coolant. I wish I could remember what episode that was.

[richardroberts]

Worked on these and other Cummins a few years ago, just before the IS versions came in. As per the B series the C series had there camshaft and cam follower issues, we made tooling that allowed you to change both without removing the engine or oil pan. All wet sleeved Cummins tend to suffer more with cavitation erosion of the liners if the DCA coolant additive is not used and maintained.

[gbrads]

Drove a lot of 18 wheelers and the Cummings 15L ISX was always my favorite. Reliable, reliable, reliable. But yes they are incredibly heavy.

[robertthompson]

I just picked up an M923A2 with the 8.3L. Thanks for breaking all this down and making it easy to understand. It gives me a good idea of things to look out for.

[farmerboy]

Combines run wound right out at around 2700rpm all day, coupled with other abuse and sometimes poor maintenance that’s why they explode more often then other 8.3s. The 8.3 in the Magnums ran around 2k rpm for peak power and would only rev to 2300 or 2400 and had less issues but a very common issue I’ve seen on every 8.3 I’ve come across is that they all blow headgaskets

[blakebreckenridge]

Very very good engine, in the Ag engines I've seen the CDC version, in the Case IH Magnum tractors with over 15k hours on them. The combine engines typically run higher RPMs, and in a combine while in operation, you have to run full throttle all the time, for the machine at the proper threshing speeds.

[fordmuscleluis]

Glad you got this Video uploaded on Everything wrong with a 8.3 Cummins

[madmax-rxik]

I think its funny that you bring up the weight being high. In my truck people (military wrecker) people complain about it being too light for the truck

[dylangoldsmith]

I’m looking to buy a 2388 combine which has this engine so I’m glad I saw this and can keep that issue around 6-8000 hours mark in the back of my head 👍

[someinternetguy]

Unfortunately, your not quite right on a few things here:
1) cavitation is an issue with all Diesel engines, the 8.3 is no more or less prone to issues with it than any other sleeved engine. There is no “band aid” required, and sleeveless engines don’t have as many issues because they are usually smaller, lighter engines which make less power.
2) failure in a combine is not any more common than anything else, and it was mostly about how Case IH set them up. That engine was in gleaner, white, Massey, and a few other combine mfg’s and they didn’t have that same failure rate. This is one of the most loved engines in Ag between 150-300hp.
3) Combines run at high idle while working, so their duty cycle is much higher than most engines.

It really shows you just looked up some stuff in the internet and watched a few videos and made this one. While your effort is noteworthy, I’d advise folks to take their advise from people who actually work on them for a living.

[peterwhite]

Most likely has something to do with the fact in combines it is running at full tilt all the time, as well as the dust clogging up air intakes and causing it to overheat. Though I have not heard of the same issues in heavy equipment, like loaders, haul trucks, and excavators, though I'm not sure if those were a common use for this engine.

[joshbergellin]

I’d say the 8.3 Cummins is pretty well liked in the farm equipment world, the 160, 170, 185, and 195 white all had an 8.3 Cummins and those are some of the toughest tractors ever built, more important is the case Ih 7100, 7200, and 8900 series magnum, I think those all had the 8.3 liter and those tractors dominated the market almost the whole time they were around, and their still one of the most popular tractors in the farm equipment world

[reubenmosman]

Great video's man, can't wait to see more. Thank you for all that work.

[MrKweezy]

I have a fully mechanical 6CTA in an offshore fishing boat and one thing not mentioned is that these engines are loud. Yeah, diesel sound good, but on a multi hour trip it becomes a drone with the engine set at constant 2200 rpm. The only louder boats I've been on are Jon Deere powered