Plugged muffler??

['strokeThis_'07]

Who alls heard of a plugged muffler that restricts bad enough the engine is down on power? I work for Halliburton and had to hotshot frac trucks back to town yesterday. On the second trip I jumped in a new truck, its actually an 06 but its been sitting in the shop getting a shower put in it (its a straight truck-no trailer) with 677 hours on it and 3500-somethin miles. So its still basically brand new. Its got a twin turbo CAT C10 in it.



So I start going and notice it has real bad response, pedals to the floor and it barely accelerates. Anyway I get on the interstate and it goes 25mph TOPS. Pull over, the frac mechanic pulls up, we can hear hissing coming from the top turbo, he says "Ill bet its a plugged muffler. " Im standin there like "dude, your crazy. Gonna take the muffler off on the side of the road for nothing. "



We get it off, and to my surprise it fixed it. The soot that fell out from inside the muffler literally looked like little chunks of coal. But I was smilin the whole way into town drivin it straight piped!! And the jake was LOUD!! My suggestion for straight-piping all the company trucks didnt go over so well though. Bummer. Whos ever heard of that before?

 

[PToombs]

Seen it on cars with catalytic converters plugged, makes sense!

 

[tgordon]

I have heard of it on Catalytic converters, but not mufflers. Since it's an '06 it shouldn't have a particulate trap, but I wounder why it is putting out enough "soot" to plug th emuffler that fast Sounds to me they might want to get the computer checked on that truck.

 

[nickleinonen]

i had the soot trap on my tahoe 6. 5TD get plugged up several times when i owned it [±85,000 kilometers]

each time they dealer just changed the "cat". . last time i fixed the problem for good. . egr system got disabled with a solid plate, cat was removed and check engine bulb was removed from dash. .

 

[abrankod]

I work in the HD truck industry and I'm seeing more and more MD and HD trucks come down the pipe with catalytic ( NOT DPF UNIT ) mufflers from donaldson and nelson. These things cost a FORTUNE (upwards of $2000) to replace and yes, they clog on a constant basis unless you really really stomp on the engine to bring EGTs way up often to clean them out. With the run time/mileage numbers you give, that truck has idled a LOT in its short life.
-Dan

 

['strokeThis_'07]

Ive also heard it on catalytic convertors, but not mufflers, and mostly those were from the 80s-early 90s when cats were first being implemented.



Yea, our trucks idle all the time on location. Most dont idle them up for some reason. My new truck (08 KW baby!!!) has a DPF, and it plugged up but still maintained 60 on the interstate! And I idle it up to 1100 or so once I hit location and get it spotted and hit the manual DPF burn occasionally... both the 06 and 08s do have a Donaldson muffler, may be that cat/muffler combo your talkin about... ?



I would have thought that EGTs would get high enough to burn some of that out, because these trucks are limited to 65mph and dont have the power to hold speed up even the slightest hills, so its full throttle pretty much all the time. Although they do tune them down when they get them, so maybe the cut-back fuel on the top end decreases the EGTs enough that it cant clean them up... ?