Cummins ISX CM871 Technical discussion

I was plagued with this issue on my 09 386. 3 t stats 1 water pump and new radiator was in the shop getting ready to do the oil cooler as per cummins tech suggestion and we noticed the fan was on backwards!!!!!! I bought the truck in jan from pete dealer and we never removed the fan but of coarse they blamed us because we did all the other work on the truck. I can't begin to tell you how much that cost me in down time. Check you fan clutch real good also. if fan and clutch good look towards the oil cooler. Are you having any soot problems? soot is why they sent me to the oil cooler.

 

Hi Red hawk, this may sound simple but what type of rad cap do you have? Try replacing it if you have the type with a spring in it it may be weak. Just throwing that out there, good luck. 200-212 is normal when pulling. High oil temps seem normal with all isx's.

 

Anyone know where to buy a delta p sensor for cm871 other than dealer or ebay? Is ebay version a reliable version?

 

Tomorrow I'm going to attempt Rawzs EGR tuneup. I have a cummins in a 2009 volvo. Its getting 5mpg. It never had any codes until this last trip it started losing power and threw codes. I'm not sure what code but will find out in the morning when I have them read. The power issue only happens sometimes when the power is good the truck runs great (except mph). Thinking maybe the egress valve sticking? Any advice on doing the tuneup? Has anyone done it and noticed a big difference. Anything else I should check or change? I'm changind the doser, delta-p, imap. And exhaust pressure.

 

Rawze has his own site at www.rawze.com if you need help

 

For those with first generation ISX's without regen or EGR like me, I have some information on engine brake maintanence I'd like to share as well.

I bought a used 2000 W900 with a Signature 565 Cummins in July 2014, and the engine brake was never working 100%. Matter of fact, 50% would be the correct figure. I had to put it in service by August, so I started running it until I had the opportunity to put it down for a day or so to start doing some work on it.

I began chasing a front end issue, with having to countersteer out of the ditch constantly. By switching steer tires side for side, it just switched the pull from the ditch to the oncoming lane. A new set of steer tires solved that problem. The tires looked perfect, no wear...but one was out of round and so I removed and replaced both. Yes, $900.00 later, but we all know how that goes.

Next I decided to attack this engine brake issue. I made an appt. to be looked at in a "highly reputable" shop in Ct., and arrived 8-20-14 for this service. I wanted the engine brake issue fixed, the oil changed, and something else...can't remember what now. After 3.5 hrs. in the lounge I was informed by a service writer that I had "aerated oil" in my system, and that means I have an issue between the pickup tube and the pump, so there's no way to solve the engine brake issue. I was mad to say the least that they dragged me there to tell me that, and wouldn't fix anything that day because they "were busy". I pulled out of there and headed to my old crackerjack Cummins guru tha I should have went to in the first place for a second opinion and counseling.

I wasn't buying the aerated oil theory at all, neither was my guru, because no matter if it's a Briggs & Stratton engine or a Cummins, aerated oil which means foamy, bubbly oil would definitely affect oil pressure in some way. It never did one bit on the gauge. Always ran at 38-40 psi constantly. Starting with the fact that the oil hadn't been changed since I got this truck yet, and the very vague record book I got along with the truck was showing the last oil change was over 40K miles ago, we concluded it was time to change the oil, and we plugged into the data port with the Cummins laptop.

The computer showed #1 & #2 cylinders were not contributing like the other 4 were, (those two were at 90-92% while the others were at 100-110%,) and doing an individual injector cutout test, we found #1 & #2 injectors were not performing properly. I decided to put two new injectors in, and change the oil of course. I also asked them to get this engine brake fixed, but they said "let's start by changing oil, maybe fresh, new oil will bring it back to life". I had my doubts with that, due to the fact that usually it's a mechanical situation with an engine brake rather than just lack of viscosity in oil. I also had them drop the oilpan and check the pickup tube to the pump, and replace the O rings and gasket to be sure of no suction issues.

The following day, I wrote the check for $3,500.00 and drove 40 miles home. Pulled into the driveway and smelled oil. I opened the hood and it was covered completely with oil. I was sick, and couldn't stand to look at it or deal with it after paying a small fortune for this work not even 24 hours prior, and still didn't have a good engine brake, and the oil was as black as before it was changed. What I determined was the new valve cover gasket had been compromised when he put the cover back on, and it was spewing out of the gasket. I didn't care...I was frustrated and walked away. That was Saturday afternoon. I went to do my own self-education online that evening and on into Sunday on these ISX engines, and found YouTube videos and some forum information to be invaluable to me on Monday 8-25-14.

I gathered enough information off the net to make my strategy for Monday. I showed back up at my guru's shop early Monday morning and slid a piece of cardboard under the truck to catch the dripping oil. Then I proceeded to tell him I wasn't mad, that this is a blessing in disguise to me, and that I am going to get this engine brake working 100% today if I have to do it myself. He said "whatever it takes..."

When the guy that worked on it Friday arrived, I informed him I was going to kind of be in charge of this repair today, and I'd like to remove the valve cover, put two pieces of cardboard alongside the engine to contain the oil as we run the engine, and I want to visually see for myself what is or isn't going on with this engine brake. He was totally in agreement, so I stood up there and watched as he cranked it up and I started depressing solenoids one by one, starting at #1. This engine has 3 solenoids. #1 controls cylinder #1 by itself. #2 controls #2 & #3 cylinders. #3 controls 4,5, & 6. When I got to the last solenoid which controls cylinders 4,5,& 6... I immediately saw what was wrong. The control valve (or slave piston) in the rocker arm itself was spewing oil all over the place as I actuated that section of engine brake, showing me that slave piston was faulty. To prove that, I swapped that bad one over to position #2 (there's six of these slave pistons built into the rocker arms that hold exhaust valves open,) and put #2 into the "bad" position #6....and VOILA! there's the problem.

Instead of changing just the one bad slave piston, I put all six brand new ones in, while I was at it. Now I have an engine brake that is the strongest I've ever experienced. I also re-changed the oil again with only 80 miles on it, because it was still jet black from the previous oil that had been trapped inside the oil cooler, compressor housing, etc. and tainted the fresh stuff. For another couple hundred bucks I figured I'd have some peace of mind and change it again as a precaution and see for myself that the blackness was due to contaminated oil from the previous owner not changing it in proper intervals, AND that the two faulty injectors I had changed could have contributed to that oil breaking down and getting contaminated with fuel, causing this "aerated oil" issue that the first shop referred to that would be the result of thinned out oil that being churned around by the cams, etc. would indeed appear to be foamy, or "airy" at that point.

Moral to the story: Do your homework before you become a slave to the repair shop. I've been around it over 30 years, so I'm not a slave to any of this, unlike a lot of newer drivers and owners...and I don't envy those that just started out in this industry with little to no knowledge of mechanical things. But that doesn't mean you have to be completely helpless when dealing with expensive repairs, if you're armed with some good knowledge as you go into the shop. I happen to have the ability to do a LOT of things besides just drive a truck, so that is an advantage. Keep in mind, if you're an owner-operator this is your business, and you need to control costs to the best of your ability.

Good luck with those ISX engines....they're not as bad as some let on they are. Like with anything else, knowledge is power.

Below is a pic of that stupid little slave piston that caused me all this grief, but in the end probably saved me a ton of money because if it weren't for the valve cover gasket failure Saturday, most likely I would have ran this truck another couple of weeks with 1/2 an engine brake some more until I allocated some time to put it down again. These are located in the rocker arms of each of the six actuators that open exhaust valves, to operate the engine brake. Cost: About $30.00 each....

 

Best post ever :smt023

I had no chance of picking on your spelling nor grammar lol

 

Not only replace the valve but replace the spring too. The new ones are stronger to hold the arms in place better. Also check rocker shaft for an egg shaped neutral detent. Really important.

 

The rocker shaft detent holes are the biggest issue, as Duramaxxed said with worn detent holes they loose oil pressure and will cause weak performance. Our shop does a jake tune up were we change shafts, control spools and springs, this brings jaking back to like new.

 

You kant catch me on spelleng or grammer....I sppells and talks right all the tyme!