: Stock V6 intake moan?



The Wrench
03-27-09, 11:06 AM
My '08 V6 has developed an intake moaning noise that sounds like it has a trombone under the hood. Occurs only under light throttle right around 2000 RPM, in any gear. Really noticeable with the roof open.
Add a little throttle or let off the throttle and it stops. Occurs only around 1900-2200 RPM, just where the revs like to stay under normal light acceleration.

I'm 99% sure it's intake moan; but I guess it could possibly be the torque converter. Checked the air filter and intake plumbing, and even replaced the filter. All is good there.
I'm wondering if it might be something in the variable-plenum-volume manifold.

Anyone ever had this?

I'm gonna pull the filter and drive it around the block, to see if it changes.

Tks,
DG

robhersch
03-28-09, 12:34 AM
My '08 V6 has developed an intake moaning noise that sounds like it has a trombone under the hood. Occurs only under light throttle right around 2000 RPM, in any gear. Really noticeable with the roof open.
Add a little throttle or let off the throttle and it stops. Occurs only around 1900-2200 RPM, just where the revs like to stay under normal light acceleration.

I'm 99% sure it's intake moan; but I guess it could possibly be the torque converter. Checked the air filter and intake plumbing, and even replaced the filter. All is good there.
I'm wondering if it might be something in the variable-plenum-volume manifold.

Anyone ever had this?

I'm gonna pull the filter and drive it around the block, to see if it changes.

Tks,
DG

A thought: I would first try to get the noise while stationary in the driveway; then disconnect the "fan belt" to eliminate alternator, power steering, water pump, smog pump, etc that could have bearing noises and repeat. If not, suggest finding station (ie, gas station or smog test station) that can put the car through a normal driving environment while not moving with respect to the ground. Either could help isolate where the noise is coming from (and likely much less costly than the dealer.
Good luck!!

c5 rv
03-28-09, 08:51 AM
I've heard this too if I leave the radio off. I ought to check the rear DVD player for an x-rated movie. Until then, I'll keep the country music playing.

n7don_srx
03-28-09, 01:27 PM
Have you recently changed the oil filter? There's a TSB related to engine noise and oil filters but no details.
Since it's an 08 would assume, if it continues a trip, to the dealer might be in order.

The Wrench
03-30-09, 07:46 PM
Thanks guys. I'll try to find more about the oil filter thing. I did change the oil awhile back, and installed a Napa Gold (Wix) filter.

I did some more looking; seems the noise is not there when the engine is cool. And it will do it a bit sitting in the garage (when warmed up).
I'm thinking maybe an exhaust heat shield vibrating?
I'll chase it some more and report any findings.

DG

gavin07
03-31-09, 03:11 PM
Did you ever find out what is wrong? My 04 V8 is doing the same thing. It is at the dealer right now and they can't seem to find out what it is.

The Wrench
04-02-09, 10:59 AM
Gavin, not yet. Weather got pretty and I got distracted by golf.
I'll let you know if I find anything.

DG