Shutting Engine down noise

[luvthesmellofdiesel]

From the time I bought my truck until last week (16K miles on it), every time I shut it off, I would always here this air suction/vaccuum sound just as the crank stopped turning, it was kinda neat actually. Now, for some strange reason, it doesn't do that anymore. It just shuts off, no noise, no nothing, kinda like shutting down a gasser. Anyone else ever heard this, or know about it, or is this just the signal that it's finally broken in? :)

Thanks,
Tim White

[Kennedy]

Chances are, you are hearing the turbo free wheel. Could be your air filter is getting dirty, OR your oil is getting old...

[luvthesmellofdiesel]

Could be... Thanks. Sounds like I should get a gauge set to be sure it's actually working (assuming it doesn't void my warranty. I don't have any aftermarket power boxes). I hear the whine, but doesn't seem as loud as it was. :-( I am at 4500 miles for my oil change (and air filter change), but they are nearly all highway. Fixin to change it when I get it back from the dealer after they fix my flywheel problem (assuming that's what it is). :-(

Thanks,
Tim

[a64pilot]

Trust me if the turbo wasn't working, you would know it.The truck would smoke and it wouldn't pull the hat off of your head. ;)

[dmaxalliTech]

not sure if this is it, but we have noticed some people getting a squeak when shutting down, the belt stop turning in a hurry with 17.5:1 compression slowing you down. The rotating force of the accesories will cause very slight belt chirp. maybe belt is wearing in a little and noise is gone. I doubt this is your noise, just thought I would share something

[luvthesmellofdiesel]

Interestingly enough when I got my truck back from the dealer last week after they had it for 3 days to replace the dual-mass flywheel which came apart at about the usual 16,000 mile mark, it went back to making the usual short air swoosh noise when the engine stops turning. Must be something about the flywheel causing this.

Also, based on everything I have read (dealer denies this of course), looks like I'll be in for a new flywheel about every 16,000 miles. The dealer did indicate that since the flywheel is technically part of the engine (the replacement engine's come with flywheels), it's warranted to 100,000 miles. Hopefully by the time in for my 6th replacement, they'll have a real solution for this problem... Interesting how this caused my "no air swoosh noise" when shutting down...

[DmaxMaverick]

This may be way off base, but I don't discount the simplist of explanations, no matter how silly they sound.

The sound you hear 'may' be the little fan built into the OEM radio head. It runs on a thermostat switch. The fan is very quiet and can only be heard (normally) with no other noises, like when you turn off the engine. The fan will stop as soon as one of the doors is opened, or the internal temp goes down enough. I notice mine when the radio is off and I shut off the engine. If the radio is on, it stays on until the door is opened, which is when the fan turns off.

If that's not it, good luck.