I had a track loader hauled with a new day cab Freightshaker last Friday. What was that god awful noise going on with the exhaust at times when it was idling? Sounded like a giant vacuum cleaner or a vacuum pump for a dry tanker but there was no pump on the truck. The driver said it had something to do with the turbo. Where's my real Bulldog Mack...
How about a DPF re-generating? Legdoc
Welcome to our tier 4 world.
As far as I'm aware Freightliner uses Detroit SCR or Cummins SCR engines which use DEF fluid and not regenerative DPF systems. I can't see a turbo making a bunch of noise at idle moreover at speed and then they tend to whistle...
Oh yeah, that turbo whistled at idle while I was loading. Sounded like it got under a load and started whistling...with a vacuum cleaner sound in the background. I haven't been around a new one for a couple of years or more. Somewhere around the time Obama got in.
The vacuum sound could very well be the radiator fan, modern fans have numerous blades on them and can sound like a jet engine when engaged. Can't see why the turbo would be winding-up at idle. Oh well.....:my2c on the subject anyway.
Sounds like the regeneration of the DPF. I couldn't find any info to verify but I think it was 2007 to 2010 that the DPF system was used. If the truck falls in those years it would have the Diesel Particulate Filter on it that traps the diesel soot. When it regenerates, fuel is injected into it to burn off the soot it has collected. It never made sense to me how emissions could be improved by burning more fuel.
http://www.youtube.com/watch?v=nDI1tuQfmPs
Now that's a real truck Hendrik. I'm thinking it was the engine fan kickin' in when that turbo started whistling cause it was hot as hell and the driver had the cod cooler on full blast while it was idling.
VGT. variable geometry turbo. A real PITA to keep operating right. its closing the vanes of the turbo to artificially create a vacuum to high dose EGR.
Oh yeah, that turbo whistled at idle while I was loading. Sounded like it got under a load and started whistling...with a vacuum cleaner sound in the background.
Is there an echo in here?
My 3500 Dodge with the Cummins dose the same thing. Does it allot in the colder months to help the engine warm up.
Very Well Put Steve ! ...... BOY isn't that the truth !!! ......... My '03 Dodge with the Cummins pulls fantastic fuel mileage out of it ....... the newer 6.7L engines get less than 1/2 of what I get ...... I just can'see how burning twice the amount of fuel to go "X " distance can be healthier for the enviroment ... even though the exhaust pipe says its less emisions .... just does not make sence . "EXACTLY" ...... some pencil necks answer to everything ! ......
Mine is an 11', egr delete, turbo back exhaust, and tuner. I get about 19 to 20 highway and 17 city. Alot less towing! The power is nice though.
I run several '05 Columbia's that do that at idle. It is much more pronounced when driving slowly under no load.
Even with the addition of SCR, the trucks still must have the DPF. By adding the SCR, the regen temps are lowered from about 1200 degrees F to just over 800 F, The SCR is after the DPF, so you pretty much have nothing but emissions junk on the passenger side of the frame on a vocational truck. With the DEF tank on the driver side, usually in front of the fuel tank towards the front of the truck. With the addition of the SCR, engine manufactures such as Cummins were able to go back to a common rail fuel delivery system, thus increasing horse power. Normal highway applications with say a 505 hp MP-8 / D-13 for every 250 gallons of fuel, you will use 18 gallons of DEF. Ap40
In my point of view it is due to the engine fans when turbo starts.
Also, even with the SCR, during a burn the engine rpm still increases generating more heat in the engine, thus turning on the cooling fan, so you will have all sorts of noise during the regen. For 2013, Navistar will finally be offering 2010 emissions compliant engines with the addition of the Cummins SCR after treatment. this is the direct result of Cummins, Mack/Volvo & Mercedes / DDC's lawsuit on Navistar for relying on government "carbon credits" to continue to manufacture non-SCR trucks into 2012. Ap40