Air sound on acceleration

[VACMAN]

On the trip home today I noticed a sound like air escaping when I accelerate from a stop. All the air gauges are normal. I pulled off the road and walked along the side while the DW pushed on the accelerator and ran the r.p.m. up to 2000. the sound was like a broken air line. coming from behind the radiator area. The more she pushed the pedal the louder the sound. never heard this before. Back on the road, when I accelerate from a stop I could hang my head out the window and you can really hear it..also I noticed that while I was accelerating I could feel a slight pulsating in the acceleration,,,any Ideas ???

[racer0624]

Just a guess but I'd make sure it's not the turbo spooling up. Of course if this is a new sound then look elsewhere. I thought our '09 Essex had an air leak at idle and it turned out to be the turbo. Put your ear as close to the exhaust as comfortable while your wife speeds up the engine.

[mrschwarz]

Is it new or something just noticed? On our Freightliner chassis, every time we stop, the water separator purges. We hear two short bursts of air. You can almost count on it.

If you are concerned, call the chassis manufacturer. If everything else is normal (air pressure, brake response, etc,) that may be what it is.

[soricobob]

I had a similar noise, took it in, found it was a crack in the turbo.

[markpj23]

Had this happen to me on a previous coach. Sounds like you have a leak in the turbo discharge hose and the hissing is the air coming from the turbo through the intercooler and then to the intake. You should also notice decreased performance as the charge air will be less. Check your turbo boost gage - does it read normal?

In our case the hose came completely off of the intake fitting and while the engine ran, it was a real dog with no power.

Time to raise the bed (or other engine access) and check out the hoses on the engine.

Good luck with it - let us know what you find.

[Parkerrs]

As stated above, possible leak at one of the rubber sleeves in the turbo to intercooler plumbing. Also it could possibly be a leak from the intercooler itself due to a crack. Symptoms would include lower power or eratic engine response unless the connection is completely broken at which point power would be dismal.
Just a thought but if you haven't been operating in high temperature areas of the country and are now it may be the cooling fan. Depends on engine performance, a Spartan or Cummins service center should be able to diagnose it easily.