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.
Follow all our accounts below!
linktr.ee/dustrunnersauto
Gear I use to shoot my videos:
(Buying through these links supports the channel)
Sony A7IV: amzn.to/3CaDvQY
Sony 24mm F1.4 GM: amzn.to/3C6sZKv
Rode Mic: amzn.to/2J0lrik
Tascam DR05: amzn.to/2LvYFjR
Neewer lights: amzn.to/2Xem68x
-Copyright Disclaimer Under Section 107 of the Copyright Act 1976, allowance is made for "fair use" for purposes such as criticism, comment, news reporting, teaching, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational or personal use tips the balance in favor of fair use. No copyright infringement intended. ALL RIGHTS BELONG TO THEIR RESPECTIVE OWNERS

[@Dustrunnersauto]

What do you think? Good engine or overrated?

[@janamaro5894]

It's a good engine.

[@wizard_of_poz4413]

It's never been any good like the m11 cummins. The isl9 just completely blows it away

[@roballan4944]

2 valve 8.3c were excellent. Long lasting in heavy equipment and marine

[@rkalkes]

Can you do something on Kubota small diesel engines? Please.

[@CurtisWithoutHandles]

Coolant elbow is a PITA

[@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.

[@lamarzimmermanmennonitefar5269]

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!

[@farmerboy9029]

Cummins makes great engines and they had good power, but I don’t think they could beat the Torque and power to RPM of IHs 300/400 series engines. IH just had the more robust design and better lug down power

[@deeremeyer1749]

Like they've had a choice in the "modern era". Tractor-wise at least. How come AF combines stayed "all IH" so long?

[@bladenrexroth2555]

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

[@Bacongrease00]

CAPS sucked

[@bladenrexroth2555]

@@Bacongrease00 His CAPS was clogged with fuel hose rubber, Algae and had rust build up. Even with keeping a fuel/water separator and filter on it.

[@Bacongrease00]

@@bladenrexroth2555 when I worked for Cummins it was a high repair item. Bosch P pumps were so much more reliable but the push for emissions and efficiency ultimately wins out every time. CAPS is very sensitive to foreign debris, bad fuel, poor maintenance.

[@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.

[@lamarzimmermanmennonitefar5269]

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.

[@carlthor91]

Agreed, all wet-liner engines have either a notification to change coolant annually, or change the coolant filter (has additive puck in the bottom) if so equipped, annually. Best wishes from the far North.

[@mayberickcanfixit7468]

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.

[@cwj9202]

It would be interesting to see that video, because it is obvious to me the problem is not an engine issue but an application issue.

[@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.

[@richardroberts8742]

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.

[@reubenmosman9466]

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

[@fordmuscleluis9710]

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

[@dylangoldsmith4353]

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 👍

[@robertthompson5084]

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.

[@jdm1066]

I have been looking at getting one of those since 2010. How do you like it so far?

[@someinternetguy955]

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.

[@nspro931]

Same with the lift pump. IIRC it only ran for a minute during starting to prime the pump but shuts off after that, and the CAPS pump does all the pumping itself. Somebody correct me if wrong.

[@wizard_of_poz4413]

Yea they're junk engines that get quickly replaced when manufacturers get something better

[@someinternetguy955]

@@nspro931 Yes that is correct, Caps pump has it own gear pump built in. Unfortionately that was a weakness, as any leak in the suction side would could cause low fuel pressure and starve the pump and wreck the piston pump side of it. Changes made to supply constant low pressure fuel via the lift pump will solve that issue.

[@bobsyouruncle1574]

Damn good engine. It's a wet sleeved, p-pumped, 8.3L 12 valve. What else is there to say?

[@madmax-rx5ik]

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

[@farmerboy9029]

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

[@wizard_of_poz4413]

Usually you aren't gonna run a combine anywhere near that fast unless older ones are that much different. Case now runs the 6.7 and 9l and 13l in their combine and tractor lineup which are just frankly superior engines

[@antoinelenouail3122]

Only the 1680s with the 8.3 turn that fast. When CaseIH went to the 88 series they slowed them down to 2450 rpm. That made them much more reliable.

[@wizard_of_poz4413]

@@antoinelenouail3122 ours with the 6.7 only turns like 2100

[@farmerboy9029]

@@wizard_of_poz4413 2388s turn in excess of 2400 rpm

[@wizard_of_poz4413]

@@farmerboy9029 ours is a 5130

[@peterwhite9546]

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.

[@m16ty]

Even in construction equipment, the engines don't get the workout they do in a combine. Modern combines are pretty much run wide open and at full power the whole time they are operating (which is all day long during harvest season). Combine threshing systems work the most efficient when ran at close to 100% capacity, and that's where farmers run them. You don't see many combines with 8,000 separator hours though, usually the rest of the combine is worn completely out before they get that many hours.

[@blacksmokin]

You need to look into this... it's because the later model ISC 8.3 L had wrist pin problems due to the pistons only certain esn where affected. What do mean Bandaids? All weat sleeved engines require those As you call bandades because of cavitational erosion.

[@blacksmokin]

Stop talking about diesels you don't know what the f*** you're talking about

[@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.

[@elroyelblander6277]

I've got one in a dozer and a feller buncher...I like em.had to inframe one at 8,000 due to oil consumption cause of rain water intrusion on account of missing rain cap.liner was pitted..all in all a good engine and design.. wonder why the combines have chucked rods..?.. think perhaps a fastener issue where a bolt came loose and Left ..then the rod existed..never seen one to blown to dissect...but anyway 👍👍

[@Kolton9330]

Combines toss rods because they run wide open at higher rpm all day. The 1680s ran at 2750

[@travismerrill6397]

I'd like to see you do a video on the Hercules multi-fuel engine that they put in the M35 deuce and a half trucks

[@m16ty]

Those were bad about windowing the block when ran at rated speed for that application. The same basic engine was used in tractors but didn't seem to have that problem, but the rated speed was lower on those models. Not a bad engine, but they didn't produce much hp for as large of engine they were.

[@sumpjunkie]

The C series is just about to come to the end of production in the UK. These were still being produced for marine and industrial power generation with a bosch p3000 pump. The highest power the c series went out to was 480hp in a marine propulsion variant that was released around 2004. It actually had a very basic electronic fuel control on the back of the p7100 pump instead of a mechanical RSVQ governor. It had an ECM. It was a stop gap to lift the c series from 450 mhp to up to 480 mhp whilst the qsb5.9 was being developed. The c series is still being built out of China for industrial and marine power generation along with variable speed construction. They use a 24 valve block and a 12 valve head with a locally produced inline pump

[@Anonymous..VQ3.5Lg35]

Mmm love this engine when she starts on the 2188, revs to 2450 rpm in the feild, cold start method is ether, im glad its got the p pump!

[@Engine_biulds]

I would love to hear more on the larger displacement cummins swaps. I know you cover allot of it in this for the 8.3. I loke the idea of replacing sleaves. Should have always been an option imo. To me ot only would have made sense to keep with what they had going.

[@jefforylaumer4168]

They also had some oil pump issues the military trucks chucked rods too

[@joshbergellin5096]

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

[@revvinevan014]

Yup your spot on, my favorite tractor of all time is the case 7200 series.

[@kgoldric]

The harvester issues is usually assumed to be running at a high rpm for hours and lots of dirt and filth being kicked up and getting in the air system. Running hot and restricted airflow is probably what's killing them. In an RV you're never pinned at high RPMs for hours and when you are high on the rpms you are moving at highway speed getting lots of air.

[@jamesfinn4547]

I like my 6cta 8.3 in my 1989 International tandem tipper. Nice little easy engine to work on especially compared to my 3406B cat or even the VT504 V8 cummins thats more complicated and difficult to get in the V

[@carabara3947]

Yeah Man The Easiest Water Pump Ever To Change 1/2 Drive Power Bar Three 10mm Bolts Sorted But That Fuel System Is A Nightmare When The Internal Drive Key Wears Causing Miss Firing Knocks When Starting I Used To Spray Brake Cleaner Down Its Neck To Spin It Up Faster Also Faulty Alternator Made The Starter Motor Disengauge Having To Let The Belt Slip Or Bridge The Starter

[@roballan4944]

The caps version of these had a different arrangement for securing roller lifters from rotating. The old style was a pin driven through the block. The newer version of caps and later common rai used screw in oring boss plugs with a pin. These were better and the lifters lasted longer. 1999-2001 were the bad years.

[@donovansavage2445]

I drove a 1997 freightliner fl70 with a 8.3 and a allison. Quickest truck I've ever driven

[@danielboucher9819]

Great vidéo you are very good at explaining how engine Works sir. I would like to have you're comments on the navistar 466e to me I thought they are a great engine Low maintenance and affortable price for parts have a nice day.

[@timf6916]

Good job.

[@alexfry9114]

Hey I was wondering what are some of the things that can make a diesel motor run away

[@OhioPalmTrees]

I'd like to hear you thoughts on the iszuzu 8.3 "duramax"

[@davbe5463]

cavitation has nothing to do with design, you just notice it much easier when you can take the liner out. it’s a maintenance issue

[@phtevenmolz5030]

The ISB 5.9 received common rail injection in 2003, not 2004.

[@donniceblakely1075]

I'll bet the farm it has to do with heat because farmers dont clean radiators and radiator screens as often as they should. I grow up on the farm and it's a never ending battle to keep a combine radiator clean!

[@joshpitcher0418]

Think we can get a video on the Volvo D13? They're absolutely everywhere and are pretty decent

[@wizard_of_poz4413]

Yea people give them a hard time but if taken care of they're fantastic though I think the d12 was one of the finest heavy duty diesels on the planet

[@joshpitcher0418]

@@wizard_of_poz4413 completely agree D12s are great engines probably my favourite of all Semi engines

[@jayfranklin4182]

you forgot the very common issue with a 8.3 cummins the external coolant leaks from the head gasket on the right rear corner and left front corner of the head, they all do it and the only way to fix it is to change the head gasket or in the heavy equipment world tell the operator to deal with it until it develops an internal leak

[@dblackkw]

I have a 1994 RV with the 8.3 Cummins I'm curious does this have a single wire to the injection pump like a mechanical 3406 caterpillar?

[@rodfreess6019]

Close, the fuel solenoid on the p7100 pump has a ground, a run wire from the ign, and a start wire to pull in the solenoid. So most people would say it has two hot wires to run the inj pump solenoid, but if you take that external solenoid off, it will run and you can run a pull cable to shut it off!

[@hopingforthebest1.9]

The C is also extremely similar to the L models, I believe they both have the same head, liner's, and block with the fuel system generally being the same between the two of them.

[@sumpjunkie]

Thats is totally incorrect the c series are nothing like the L10 or the M11. Not one part in common and runs two very completely different fuel system. As much as the B series was the small brother to the c series, the L series was the smaller brother to the N series. B and C series are regarded as midrange product were as the L and N were in the heavy duty stable.

[@hopingforthebest1.9]

@@sumpjunkie I was referring to the L9, not the L10

[@sumpjunkie]

Sorry about that. Yep the electronic version do share commonality in most external parts.. The 8.3 electronic engines never went to tier 4 or EPA 2010. So the 8.3 is only really being built for marine propulsion and non t4 industrial product

[@Jon-uj2uw]

I have read even caps can be reliable if you treat it right don't be sad if you got one

[@johncholmes643]

8:00 those are Caterpillar 3400 series liners...

[@herndondumptrucking]

Can you swap the 8.3 with the 5.9?

[@nicholassilvestri1804]

Great content as usual. You seem to love diesel engines..how about showin’ some love for us TDI guys😉

[@fastinradfordable]

An ahu 1.9 Tdi is essentially a Cummins. Hell it can use a Cummins pump. Pistons are same. Injectors are basically the same. It can make power of a 4bt. And it’s less than half the size

[@nicholassilvestri1804]

@@fastinradfordable its a cummins-lite

[@nicholassilvestri1804]

@@fastinradfordable Close but not exactly. cummins would never use a timing belt lol. The 4bt is a cam in block and much much larger. Cummins use grid heaters instead of glow plugs. The cummins R2.8 is the closest you can get to a tdi

[@user-hu5zh1dw5p]

I am struggling to find the difference between the 5.9 and 8.3 engine, I opened both engines everything looks the same including pistons and Cylinderhead wondering if you can help me out on this

[@sHoRtBuSseR]

It's just larger, and uses wet sleeves instead of parent bore. Also I think 2004 and up had roller cam where the ISB didn't get roller cam until 2019.

[@carabara3947]

Is It True That The Army Vehicles 15L ISX Had A Flick Switch Incase Of Incoming Fire Or Attack Would Cancel Out All Settings Giving It Monster Power For 15Mins

[@zsazsa3814]

very reliable and versatil

[@Turbo-wj9qc]

And still the 8.3 powered ih combines are much more valuable than the 466 powered ones.

[@chrisstackhouse8374]

Combines are engines are reviving at 26 to 28 hundred rpm all day every day most of the time under heavy load.

[@aaronmcconkey1062]

I love internal combustion motors

[@michaelsekavec9291]

The combines are governed at 2500-2700 rpm and run full power and rpm for most of their hours. Other applications limit to 2300rpm or less…not really a mystery.

[@desertratgaming9865]

This gave me an idea. To buy these out of military trucks then set them up for marine use and sell em to the boat ppl 😂

[@bulkchart3239]

so the combine issue would be solved if they just check the oil with every fuel up and check the gauges once in a while?

[@erikjohnson1482]

I have a low horsepower 6c in my commercial fishing boat... I'm pretty sure I'm 240-260 horsepower, I bought her with 8650....

[@Robert-tt5tg]

DT466 is not near the motor that the 8 L Cummins is 8 L Cummins has quite a bit more motor, anyone that has run a DT466 and can tell you that it becomes a tell is quite a bit more motor

[@marcturk4410]

The EPA with all their computer mandates on alot of engines is the problem👍

[@jj4791]

Its not computer mandates, its emissions mandates. Computers (ECUs) greatly improved reliability, fuel efficiency, and power. Emissions mandates on NOx for example require Exhaust Gas Recorculation (EGR) which injects dirty sooty exhaust gas back thru the intake of the engine, those soot particles wear out rings exponentially faster. And also coke up valves, wear valve seats, stems, and ruin your clean oil faster.

[@marcturk4410]

@@jj4791 NO" its and or both , my friend has a 95 Cummins with over half a million, not a problem one, people with the computer controlled junk from FORD , RAM , OR GM nothing but problems..Period!!!🤔🤣🤣take care and good luck too ya👍

[@pilsman2733]

The beard

[@Robert-tt5tg]

Well I can tell you this much from experience it's a dirty application combines are known to occasionally run hot and they don't get mean teams very well they don't get the oil changed as frequently the radiators are frequently dirty I would imagine you haven't had that much experience with harvesting, like I said it's a dirty application

[@frankiethefin886]

Do video on volvo d12

[@stewartmelzer939]

i have a 4bt 4.4 l marine engine in a25 ft southwester it has 786 hrs it is used commerical fishing great 36 mph

[@stewartmelzer939]

it has a sterndrive turns a 19x19 wheel

[@Matthewzilla]

They like to add windows in the blocks after a few years.

[@CITYBORNDESERTBRED]

Shots out to DOOMSDAY! 🤘🏾

[@JohnCamp]

Emissions are how I mark my territory.

[@stigtv9758]

Can you do a video discussing the Cat C15?

[@wizard_of_poz4413]

Why, there's millions of hours of boomers worshipping them

[@Robert-tt5tg]

Yeah it's an older style motor older casting it's definitely going to be heavier

[@herbscheit2061]

Cummins introduced common rail in 2004? My 5.9 has common rail.

[@herbscheit2061]

And its 2003

[@phtevenmolz5030]

@@herbscheit2061 yes, exactly. 2003 was the start of common rail.

[@erikjohnson1482]

I want to know more about the 8.3, lowest horsepower rating, with a dry stack exhaust, and a keel cooler. I got almost 10k hours on her.... I'm an Alaskan commercial fisherman

[@bryanc9470]

The 6cta is 450hp in the marine application

[@richardmckee9319]

They made a 480hp also

[@SBDScott]

"Diehard diesel fans are going live, and die by their fully mechanical engines." Yes, I imagine that is correct. I will die by my mechanical 8.3, with it idling while I kick the bucket, and it will probably still be running when my kids' kids inherit it.

[@beyondthewizard2347]

That caps pump fuel system fitted to buses is dreadful. It made them very unreliable & expensive to repair especially when compared to the p-pump. The cummins fault codes of death 111, 274, 275, 276, 277, 279 & of course the code of anything on the low fuel pressure side 329. I still work on these engines, but they are becoming few & far between as the cap pumps are very expensive. The only good thing about the pump is the ability to replace parts of the pump rather than a complete pump and considering a complete pump is close to £6,000 that is a good thing. Unfortunately the icv on its own £1,200. The lift pump 278 is close to £500. The caps fuel system engine wiring was actually rather robust. The 50 pin deutsch ecu plug had a nasty habit of coming apart leaving half the housing in the ecu a load of exposed pins in your hand. The cam & crank sensors were behind the pump & could be a real pain to replace & it was worth replacing them when changing a engine harness. For all its faults it is still better than the Bosch VP44 fuel pump found in other engines.

[@superjesus4307]

Better? If you don't mind the 8.3 throwing rods and the 8.9 blowing headgaskets.

[@floydgould4401]

You forgot to mention the 7.3 powerstroke.

[@wizard_of_poz4413]

What about it, that it's a mediocre engine that's famous for being the only powerstroke that's too weak to blow itself up regularly

[@floydgould4401]

@@wizard_of_poz4413 Well under powered from factory is true however with a few added bolton's it can make 450hp plus and all the while still be very reliable. I'm saying this because I have one that pumps out 500hp from 4 months after I bought it new and it now has 300thou on it and I haven't put a spanner on the motor since except for services and a couple of sensors. I definitely think the 7.3 has a very reliable history.

[@wizard_of_poz4413]

@@floydgould4401 ok so you had to shell out a small fortune in mods to make an outdated hunk of shit that's well past its prime even remotely competitive with a modern engine that's better designed and on a more robust chassis in essentially all cases. I'm not trying to be mean but if the internet was real then the first time I cranked a 6.7 it would shoot pistons out of the hood and catch on fire

[@floydgould4401]

@@wizard_of_poz4413 No offense taken, I'm just sharing my experience and knowledge from a truck I've owned for 18 years. It cost me $ 5800 for the upgraded mods and was money well spent. I do like the 6.7 but the have all the dpf crap on them.

[@Friedrich-Wilhelm-1980]

see id take the DT466 over the 8.3 any day

[@jgscs61]

I have 6 motor 8.3 mechanical pump whit over million miles still running like clock, no one beat Cummins 8.3 special the black one's with 300hp,best results 8.3👌🏽💪🏿👊🏾 and no problems never problems forget that nothing wrong whit

[@deeremeyer1749]

That's a "Case-IH" engine. Not a "Cummins".

[@jpxc1329]

Do everything wrong with cat c9 engine

[@Alehyn666]

back when engines were real engines. junk thats produced these days is just chokingly insulting

[@nathan1sixteen]

The only “problem” I’ve ever heard about these engines is that they simply don’t make any power for an engine of the size/weight. They also don’t have a lot of aftermarket support to build power

[@bladenrexroth2555]

They have about 45% of the aftermarket that the 5.9 has. You can get bigger delivery valves, marine injectors, marine cams, head stud kits, rod bolt kits, 3-4k governor spring kits, high compression marine bowl style pistons, valve springs, stronger push rods and a few other things. Couple of marine grade parts, fire rings, head studs, rod bolts, p pump modifications and a compound turbo system and you can push upwards of 600 hp. The QSC variants have seen up to 700+ hp. It's just very rare to see anyone actually do it when the 5.9 aftermarket is swamped. To be honest. The 8.3 is actually way cheaper to build from scratch for big HP and TQ. They'll easily produce M11/N14 numbers for half the price of a 5.9 build.