Cummins isx liner problems

Cummins isx liner problems DEFAULT

Cummins ISX: 3 Most Common Problems

Preface: What You Need To Know First

It’s The Popular Kid

It goes without saying that the Cummins ISX is one of the most popular and well loved diesel engines on the road today. Initially released in 1998 as a response to tightening EPA emissions standards, the ISX replaced the N14, Cummins’ original workhorse engine.

The Cummins ISX is definitively North America’s most popular heavy-duty engine. And the only engine offered by every major Class 8 truck manufacturer. With horsepower ratings that range from 400-600 and up to 2050 pound-feet peak torque it’s no surprise that this engine is a favourite for fleet operators and drivers alike.

But despite the engine’s popularity, it isn’t perfect. Let’s run through some of the most common issues.

Simple specs. Superior performance.

Advertised Horsepower: (400hp, 298kW)(450hp, 336kW)

Peak Torque: (1450/1650 lb-ft, 1966/2237 Nm) (1550/1750lb-ft, 2102/2373 Nm)

Governed Speed: 1800 rpm

Clutch engagement torque: 1000 lb-ft, 1356Nm

Cylinders: 6

Dry Engine Weight: 2964lbs

3 Common Issues with The Cummins ISX

1. EGR Valve Leaks

Like many other engines with an EGR, the Cummins ISX is prone to typical EGR problems. On the ISX the culprit is often a leaky EGR valve. This can seem innocent enough but the problem will compound over time and it’s often difficult to diagnose.

What to look out for:

  • Fluctuating coolant consumption
  • Coolant consumption that’s faster than normal
  • White residue left behind by burnt coolant

If you suspect a leaking EGR valve, it’s best to bring your Cummins ISX to our experts.

2. Flattened Camshafts

Notoriously, every model and rendition of the ISX has had issues with the camshaft. It’s prone to flattening out. This is largely because of an issue with the rocker arms. An issue in production with the rocker arms starved the components of proper oil from which makes them stick and hit the camshaft. This will eventually cause the lobes to become flat.

There aren’t specific symptoms that will indicate whether you have these faulty rocker arms. So it’s very difficult to diagnose until you’ve already seen a drop in the performance of your engine.

3. Dropped Cylinder Liners

The ISX is a mid stock steel cylinder liner equipped engine. That means that from the factory you have a cylinder liner that goes into the engine block and it’s supported halfway down the liner. If a piston seizes the cylinder liner breaks at the bottom. If the connecting rod or piston gets free of the liner it starts to destroy the whole engine block. Which is not only obviously detrimental to your vehicle but also very expensive to fix. That’s why you’ll want to diagnose any issues early.

What to look out for:

  • Overheating engine block
  • A drop in pressure
  • Coolant leaks

Sours: https://www.adrenalinediesel.ca/post/cummins-isx-problems

Rawze.com: Rawze's ISX Technical Discussion and more

Pages:12

Here the driver had an 870 with 1.4 million EGR miles on it. He was running two gallons of Lucas every oil change to keep oil pressure when he finally decided to do the rebuild. Guess what?.....take a look. the wrist pin broke and was rubbing the side of the liner.

Just dam lucky that the piston didn't get cocked and jam up. Then the block would have a big hole in it.

there is a snap ring that holds wrist pin in , that to me looks like piston skirts rubbin on liner as piston tilts im sure that rod in junk also at the top / piston end

That's a very common issue on all cummins isx engines , main cause is low RPM operation under high load in wrong gear . I have seeing 2 million mile ISX engines without a rebuild and still running strong , new ISX cm2250 and newer use small inducer and large exhaust side , making the low RPM operation a lot easier on the engine , in translation it does not choke up the engine because the turbo spools it up much faster . I have seeing guys snap rods , and in some occasions bend a crankshaft.

To avoid this keep the RPM's above 1350 under heavy load and under 1650 , much of it depends on truck set up , sometimes diffs play major role, not every truck was built to same spec.

I have a thought on why liners drop on exhaust side of the engine other than it being the thrust side of the engine. I think lugging is a major reason for liner drop.

Take a look at this carnage! I'm impressed.
https://www.youtube.com/watch?v=S9tU_uGBDKU

(03-05-2016 )gearhead Wrote: [ -> ]I have a thought on why liners drop on exhaust side of the engine other than it being the thrust side of the engine. I think lugging is a major reason for liner drop.

my guess would be heat , heat is a killer will take tension out of rings warp heads valves turbo's
exhaust manifolds bolts an pistons . depending on how the coolant flows in the engine my guess on the exhaust side there is hot spots , sure the engine will cool going by the temp gauge but there is rarely even cooling in a engine a there is always hot spots , that being said metal will compress more on one side if its hotter then the other , so if u water temp is say 200 an u exhaust is 800 over time i can see how the would compress a lil more . one side the head u have cool air coming in an the other u always have hot going out . heat will make u power but it will also shorten u engine life . just my 2 cents

(03-05-2016 )DRISX Wrote: [ -> ]That's a very common issue on all cummins isx engines , main cause is low RPM operation under high load in wrong gear . I have seeing 2 million mile ISX engines without a rebuild and still running strong , new ISX cm2250 and newer use small inducer and large exhaust side , making the low RPM operation a lot easier on the engine , in translation it does not choke up the engine because the turbo spools it up much faster . I have seeing guys snap rods , and in some occasions bend a crankshaft.

To avoid this keep the RPM's above 1350 under heavy load and under 1650 , much of it depends on truck set up , sometimes diffs play major role, not every truck was built to same spec.

I run 150-190,000lbs loaded so I've never been very big on lugging a motor, when I'm pulling a long hill I find the gear she'll pull it in, cut I back half a hole and let the motor breath. I'll do the same thing in windy days that I can't outmuscle the drag to run typical road speed. I'm usually running it between 16-1800rpm when I do this. The idea is to create air speed, get that hot exhaust moving and away down the exhaust system quicker to help dissipate heat retention.
What are your thoughts on this practice? It seems quite common thinking among the highly mechanically inclined HH'ers I know...

***edit to add for support of my theory***
I had to do an inframe at 460,000 due to a cracked head. I firmly believe this head was cracked for a very long time and I couldn't convince my local Cummins dealer of this while it was under warranty. At 460 (I time out before I mile out) the compressor failed and pressurized the cooling system revealing the crack which was in the intake side of number 2 of a CM871. Other thaa the obvious long term coolant leak damage, everything else looked good. My S/N was smack dab in the middle of the bad ones that were dropping liners like the local whore when an aircraft carrier docks, and I didn't have one shift. There was no fretting on the liner shelf at all, I didn't even have to cut the counter-bores, just dropped in the updated liners with the shims. If you want an idea of how hard I work it, I can't keep bolts on the EGR cooler over #3 & 5, the torque twist breaks the heads off them every time I replace them.

Hammerhead , it's not so much about air speed , but more volume of air . Diesels rarely run at stoichiometric . Most of the time they run lean and respectively low EGT . When pushed hard there's barely enough air to provide proper combustion . The molecules of oxygen content in the air itself is what is getting in reaction with the fuel molecules. To make it easy to understand I'll say : given amount of hydrocarbons can get in reaction only with corresponding amount of oxygen . The excess oxygen and the rest of the gases in the air are heat carrier to outside of the combustion chamber . So here it comes: Not enough air - high EGT . To much air - very low EGT . To get the best efficiency of the engine is a matter of a fine balance between both and correct mapping of everything else . Very difficult task!!!
Unilevers , Gearhead and Rawze have gone a great distance researching and experimenting to find the best compromise for most every day use . On other hand you're on the extreme.
I think you need CM870 CPL8518 with HX-60 touched by one of this highly regarded guys.
Disregard what I think . It's just biased opinion.
People are saying: torque is needed to get rolling. Power is needed to keep it moving ones it gets to speed . With 1600-1800 rpm engine is in the power band to do what you need . The torque curves down to protect the engine from to much stress and rpm/power takes over .
The best place to put your pyro is just before the turbo so you have the exact temperature that hits the turbine . If I recall correctly anything above 1350-1400*F for more than 5 min will kill the turbo . The probe on the outside takes time and if fan is on , the readings is just a guess of what actually hits the turbine, cage and nozzle.
It's just my take on this pyro probe placement .

Pages:12

Rawze.com: Rawze's ISX Technical Discussion and more > Big Truck Technical Discussion... > Things that may help others... > Anything can happen....take a look

Reference URL's
  • Rawze.com: Rawze's ISX Technical Discussion and more: http://rawze.com/forums/index.php
  • :
Sours: https://rawze.com/forums/archive/index.php?thread-125.html
  1. Profile picture unknown
  2. F 18 home cockpit plans
  3. Skyrim add item

Rawze.com: Rawze's ISX Technical Discussion and more

Pages:12

Now I know it's taboo to speak against shimming liners around here so I'm just asking for real world experience on the matter. Has anyone measured a seated liner I.D. for out of roundness with some sorta torque plate and 15 thousandths crush?
It seams everybody's favorite height has risen a thousandth a year since big h.p. has become more easily obtained. Just a theory I had but I'm thinking you might end up with an oblong liner even with a midstop in the middle.
It's been years since I've done any kinda engine work like this but I found out the hard way how accumulating tolerances can distort even the biggest chunk of iron.
If I were rebuilding an engine knowing it wasn't intended for more than 600hp I'd concentrate more on all six pots being .0095
+/- .0005 on any one hole.
Just saying ;-).

Theoretically you have valid point. But only theoretically!
Real world results are more then eye opener. As long are interpreted right.

Now think for a second what consequences will have a simple statement from engine manufacturers,
meaning something like that : - Uhm , ok guys, our liner protrusion and head gasket crush calculations just fail short off just about 3-4 thousands . So that’s why so many of your engines have liner fretting issues leading to combustion gases in coolant sistem , hydro lock and extra ventilation/inspection holes in the block.
Oh ... and we should of install an bypass oil filter at the factory, so you have a million miles engine and keep your money in your pocket.

Disclaimer:
I’m not looking to start anything with what I wrote.
It’s my way off thinking and understanding the world in between the lines.

(02-23-2018 )schISM Wrote: [ -> ]Now I know it's taboo to speak against shimming liners around here so I'm just asking for real world experience on the matter. Has anyone measured a seated liner I.D. for out of roundness with some sorta torque plate and 15 thousandths crush?
It seams everybody's favorite height has risen a thousandth a year since big h.p. has become more easily obtained. Just a theory I had but I'm thinking you might end up with an oblong liner even with a midstop in the middle.
It's been years since I've done any kinda engine work like this but I found out the hard way how accumulating tolerances can distort even the biggest chunk of iron.
If I were rebuilding an engine knowing it wasn't intended for more than 600hp I'd concentrate more on all six pots being .0095
+/- .0005 on any one hole.
Just saying ;-).

It is the block mid-stop that deflects during crush, not so much the liner itself. I have seen guys use too much protrusion (more than 0.017") and distort or crack the mid-stop in the block.

The optimum seems to be 0.0014" - 0.0015" on anything 600hp or less to yield a sort of maximum holding pressure while still in the safe zone of deflection tolerance.

it is also not typically the "Bang" of a piston that makes them fret liners. It is internal wall friction in the opposite direction of the rod as the piston drives the rod downward. That is why they always fret to the exhaust side, opposite of rod deflection during the compression stroke.


The red engine maker themselves have had issues with this since the birth of the ISX and the mid-stop liner. they have had countless tweaks over the least several years because they know is it a weak point. - I doubt it ever gets fully solved actually. I don't see them offsetting bores, increasing rod length, or doing any of the other things to relieve it like other engine makers have done in the past.

The problem of this kind of internal friction is in ALL engines that have a crank and pistons. Many engine companies relieve this problem with things like offset wrist pins, offset bores, offset heads and valve seats, longer rod length, and other tricks to reduce internal friction of this type. The red engine maker does it by a lower then normal recess in the top of the piston on the exhaust side, but obviously it seems that it is not quite enough at higher HP levels on its own due to the mid-stop liner designs?.

Because it is an issue that will likely never be solved, precise control of combustion burn length is needed as a supplement to any sort of liner height modifications as a prevention.

(reference)
http://rawze.com/forums/showthread.php?t...8#pid19318

Just thought I'd mention we used an IPD kit and the liner's are sitting 12.5 thou proud on the factory cut ledge. The Cummins liners came out at 9 thou.

Not worried in the slightest about it lasting.

(03-02-2018 )Joesixpack Wrote: [ -> ]Just thought I'd mention we used an IPD kit and the liner's are sitting 12.5 thou proud on the factory cut ledge. The Cummins liners came out at 9 thou.

Not worried in the slightest about it lasting.

it will last at 12.5 as long its not pushed hard. thats a decent number if they are not fretted.

Pages:12

Rawze.com: Rawze's ISX Technical Discussion and more > Big Truck Technical Discussion... > ISX Related Help > Liner protrusion

Reference URL's
  • Rawze.com: Rawze's ISX Technical Discussion and more: http://rawze.com/forums/index.php
  • :
Sours: http://rawze.com/forums/archive/index.php?thread-2786-2.html
Blown Head gasket - Dropped Liner - Pressure in Coolant - Cummins ISX

.

Isx problems cummins liner

.

ISX Engine re build PT27 Liner inspection and counterbore prep by Rawze

.

Similar news:

.



208 209 210 211 212