I just drove to Cedar City, Utah today from Vegas in my 7 month old MCS. About halfway here I noticed that my fuel consumption was less than it should have been..~26 mpg. Having just driven through some mountain passes at high speed (90), I figured that was the cause. When I turned down the radio, I noticed that my car was making a faint moaning sound that only happened when I was traveling over 70. I immediately went to goodyear and they checked for play in the wheels (wheel bearing problem) or cupping of the tread. They found no problems. The sound doesnt change when I engage the clutch or take it out of gear which leads me to believe it is not engine related. Has anyone else had this problem? Any input would be helpful.

Thanx

 

the rubber tube on my pcv valve is a moaner; sort of like an oboe reed. there is a recall/fix for this part.

 

Here's an experiment to try:

Run it up to 70-80 mph or so and listen for the sound. Now switch your air conditioner recirculation to off. Did the sound go away?

 

It turns out that the noise was the road surface itself. When I turned off my stereo, I was traveling on a stretch of highway that caused the strange howling sound. When I got 5 mile out of cedar city, the sound went away and never returned. i feel pretty stupid.

for all you motorers in Utah, watch that stretch of I-15 near Cedar City

Thanx for your input