Cummins ISX coughing

So, how long did the issue happen. I am being told from Cummins this is normal. They are telling me I should not
spend the money on a new turbo. This is a noise that happens all the time. I told them for the last 37K, I didn't have this noise.

 

I've been trying to find out if this is normal, why haven't I seen too many people discussing it.
This is for a Cummins ISX 870 engine.

 

Back in the 'day' when trucks actually pulled good this turbo stall sound was very normal and there was never any turbo failure because of it. As for the coughing under load that the egr valve being pulled open prematurely. Disconnect the egr and see if it goes away. If it does get your egr deleted for the same cost as a new one less the labor and your truck will gain about 10% in mpg or more and have way less maitenance issues.

 

You should check to see that the turbo actuator is working properly. Inside the aluminum hosing there are three seals with a white grease on them. Over time the heat from the turbo bakes the grease and that prevents the piston from sliding easily in the housing. Also make sure the turbo actuator control is sending enough air to the turbo actuator. I had a Cummins shop tell me that I needed a new turbo. I took the truck home. I bought a turbo elsewhere and put it on. Upon disassembling the 'bad' turbo I found nothing wrong. The actuator was sticking and causing my problem.

 

Too many mechanics are quick to blame the turbo/egr valve for these kinds of problems. Before resorting to replacing the more expensive components on the engine, do a full EGR tune-up. All the ISX engines have this problem, and this clears up many of the turbo and power loss issues, especially for the '08-'11 year designed CM871's. It is not a cure-all for every problem, but is a necessary place to start, eliminating all the smaller possibilities.

What to do, and some good info, is listed in this post...

http://www.thetruckersreport.com/tr...y-buy-my-next-truck-should-2.html#post3422407

 

Sorry to get back to this one so long. I've been on the road for ?? 5+ months. Long time..

Anyway. Basically, I replaced the turbo, and actuator with no such luck. Replaced shortly after the initial writing
of this message. (Now I have a spare turbo) Anyway, The noise went away. Only after I stopped shifting at 1000 RPM. If I shift at 1000 RPM, it is still there.

What is an EGR Tuneup?? I've never heard of this.

I did hear that the solution was to clean up a set of tubes on the cold side of the engine near the rear. I think the cost is $200. I don't remember the name of the tubes, but, I've been told these tubes get clogged especially on the older ISX engines. 870 (Pre 2006) The newer ones are suppose to be insulated better to prevent condensation/clogging.

 

Those tubes you are talking about are the pressure differential tubes. There are two of them located near the fuel lift pump. They can be removed and cleaned out.