2005 CXN AC-427 engine problems

[br549]

The truck has 950,000 miles on it, new egr cooler, egr valve, turbo pressure relief valve in intake manifold. It started popping and a puff of black smoke out of exhaust pipe maybe 5 or 6 times in a 2000 mile trip, no set pattern cold, hot , on a pull or just cruising down the road loaded or empty. Egr cooler was put on 4 months ago. Replaced egr valve 3 months ago. Replace egr valve 2 weeks ago thought it might be sticking but still does it, it does not put lighting bolt or a code when it does it. The next week it went 400 miles before it done it and did it about 4 times after that. This week it did it about 50 times, He thought it was going to quit in Houston and than it quit doing it till he got to Jackson, MS. Also I had replace fuel supply pump when it started doing this because it had 600,000 miles on it but it was showing good fuel pressure. Has anybody had any problems like this? I was thinking injectors, but any injector I have seen before when they gave problems the did it all the time. It got the power leash engine brake on it, I think maybe it is coming on maybe 1 cylinder for 1 second causing it to pop? It is driving me crazy any suggestions? I've drove it 200 miles myself and can't get it to do it. The truck runs about 2200 miles a week. Thanks

[bbigrig]

I had a 2005 CXN (355-380 Maxi cruise) that would puff black every once and a while (would make a choo-choo sound with it at times) wouldn't happen all the time but there were days when it did it would loose a lot of power and almost shut the truck down coughing black until you let off the throttle and let it "gain its composier". It turned out the Vanes in the Turbo were worn and starting to stick from time to time. Check the turbo operation....Seen the same problem with the 60 series DD EGR engines. Good luck.

[staxx]

Replace the o-ring at the bottom of the exhaust brake solenoid in the rocker shaft on both heads .

[br549]

Thanks Staxx, I replaced the O-rings on the engine brake solenoids and its ran 4500 miles since and no problems.

[Mackpro]

All ASET engines ( AI and AC models) that have the Powerleash engine brake need to have the rocker arm hold down bolts cheecked or replaced. We have seen many come in with broken bolts, broken rocker arm shafts and at worse needing a cam job due to a shattered roller rocker. Please check the part # on the bolt heads! I have seen broken bolts lead to broken rockerarm shafts which can cause oil pressure to get into the powerleash oil passage causing the engine brake to engage randomly going down the road.

rockerarm bolts.pdf

rockerarm shaft.pdf

[bullhusk]

I have a couple of 14 liter Detroit's with the newer wing turbos that did the same thing your Mack is doing, we had to change the turbo's

BULLHUSK

[br549]

Mackpro68 We replaced the bolts when they broke when the truck was about a year old, and also about 2 or 3 years ago when they changed bolts again, also the fan hub broke off at about 60,000 miles both under warranty but I think Mack handle all of this stuff bad they should have had a recall on these thing, they knew they were bad, we broke down on the road both times, warranty covered it but not load delivered late plus loss of other loads because we could not pick up on time plus driver motels and pay. Another guy bought a truck at same time and got rid of his at 80,000 miles because of so many breakdowns on a new truck, It was his first New Mack, he traded for a Peterbilt. We have been running Macks since the 60's, but after the first couple of years it has done a pretty good job, but I still don't understand why when they know problems like that they don't recall before you break down a thousand miles from home. Enough venting I guess, but thanks for advice on the bolts.

[william farmer]

2005 mack cranks but want start checke all fuses but no luck