Hi guys,

Volvo 240 '92

I've got this sound that happens only when I accelerate the car. When it's cruising, no sound. When it's enough gas to just keep the speed, no sound. When it's in neutral, and I gas I get it for a second, then it stops. When I gas it, loud, consistent noise. Sounds like a lawn mower or a tractor or something like that. Like a harley . . . ?

Again, I've searched around but I've had a hard time pin pointing the type of noise I'm hearing. I don't think it sounds like a "ping;" it sounds more like a lawn mower. I hear it coming from the hood when I'm driving, and if I have the window's down, then I can hear it reflecting back from Interstate walls for example.

I drove it from Upstate NY to DC with this condition, so it doesn't seem like an acute issue. Kind of like a muffler problem or something?

Anyway: Can I check the computer to pinpoint it? I've looked at the Haynes book and can't quite see the exact problem.

Any thoughts?

Maybe an exhaust leak at the Exhaust manifold. Look for black exhaust 'dust' down the complete exhaust system.
Exhaust noises do get louder when driving under a load.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html http://cleanflametrap.com/tony/

How can I check for the "dust"? In other words, can I look down the end of the Muffler? Or what's the best way?

Sorry for my ignorance.

If you hear the sound under the Hood. Open the hood, and look for dark traces of 'soot' on any part of the exhaust system from where it bolts to the engine down. If there is a leak, the soot will have come out of the leak.

OR
have the hood open and have someone listen for the sound as you sit in Neutral and rev the engine a bit. You did say you can hear it briefly when the car is in Neutral. hopefully a partner can help narrow down the location of the noise.

Does it seem to be noisier when the engine is cold?
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html http://cleanflametrap.com/tony/