Cummins ISX CM871 Technical discussion

nothing rude and no offence taken... need to hear it all. 20 years ago I was a Ford mechanic... didn't like being told by the service manager to tell people the need things they really didn't. I've been an O/O for about 24 hrs now... I want to learn as much as I can ,to do things myself, and I hope I am someday posting answers not questions here.
Tell me more about Insite and Nexiq link.

I don't plan to let this engine be a pain in my arse.

thanks again Ashman!

 

It looks to me like(on page 3 second picture) they are about the same "size" but the pressure sensor looks like it' s the one closest to the flange, the temp sensor appears to be closer to the block.

 

How about using a small DC Bench type power supply to substitute the engine sensor output voltages to the ECU...

Is there information as to what sensors put out what voltage under different conditions, eg. what voltage from the sensor reads 205 degrees on the trucks oil temp guage etc....

You should be able to do the same with all sensors that send a simple DC voltage to the ECU to substitue for the sensor.

With this type of info , one could pull the sensor plug, substitute the supply voltage , that would check the guage, wiring etc in one shot, rather than go around changing sensors for no real reason... especially if you don't have a box of all your sensors handy...

Where would one find a list of parameters supplied to the ECU when things are running normal in a test condition, if we ever got a new truck I would like to have this list for benchmarks, even an old truck that was running good should have a list of benchmarks for all the sensors I would think.

Is this info supplied with the NexiQ software. If so why do they just keep blindly replacing this stuff in the shops??

 

I had a guy call me recently with a cm870. Blowing black smoke, low boost low power and running hot. They had taken it to a dealer where the 'trained tech' had spent all day 'diagnosing' the problem. They were sent home with a egr cooler and a egr valve because the egr cooler was 'blocked'. They called for a second opinion. I drove out to thier garage, hooked insite up and did the turbo/ egr fitness test that Cummins put in the program. Turbo failed twice. After I called the customer to report the findings, he asked how I did it so quickly. I responded 'by using the same program the dealer has'. The next day the mechanic asked how I knew the turbo was fried? cause the backside fins were completely burnt off. The dealers have the technology they just choose not to use it or are not trained to. So they throw parts at it untill the problem is solved, then they kick a guy out the door making 30% on the parts. Sick

 

That may be part of my problem. If I post the tag off of the turbo, can someone tell me if it's been replaced?

 

Black smoke, low boost, low power, high temps, a good mechanic would not need a laptop to go straight to the turbo with all this information provided. All the new sensors and actuators on these engines seem to throw people off, sometimes it pays to go back to the basics and think about fuel and air.

 

I agree that the tech who troubleshot that complaint had no idea what he was doing but I can not agree with the concept of immediately going after a component that costs over $2,000. My biggest issue with the repair industry as it stands today is not the lack of "qualified technicians" as it seems if you can retain knowledge from a book or computer led instructions you too can be a "qualified" technician, but a lack of technicians who understand how the engines operate. Now I don't claim to be amazing at what I do but from what I see in the shops I've worked for many people are hired as if they are gods gift to engines because they have thousands of certifications that say they are apt. I worked with a technician not long ago that if I were a customer and he was to explain to me how diesel engines operate and all the systems around them I would think I had just hit the repair tech jackpot. But the moment you put a wrench in his hands and asked him to perform even the simplest of repairs he had no idea what he was doing. Another problem I see is technicians who have been in this industry for decades but have chosen to not keep up with the technology and instead of learning it they go with old school thinking and attempt to repair newer style units and the unit continually comes back over and over again usually crapping out the same component they just replaced. The very first thing I check when a unit comes in with the symptoms given would be the intake manifold boost/pressure sensor. As if this sensor fails in range causes the same symptoms that were just outlined. I find it appauling these engines and unit we work on are HUGE investments for someone especially owner operators and should be viewed as such. And to see people I wouldn't trust to change my oil T/S a problem on something someone has their livelihood resting on is just sickening. I mean imagine you owned something like a Maserati and someone with this sever lack of ability were to work on it, I bet there would be court cases left and right. Being that majority of drivers are more of the blue collar and not of the white I think plays a giant role in it as companies thinking "hey, that driver cant afford a lawyer. Theyll just take out another loan and buy another truck"