First time Volvo owner here. Engine on my s40 has developed a growl. Anyone know what this might be???

attaching a video

this is a 2010 s40 no turbo

 

attachment of video I hope worked lol

 

Hard to say for sure, but it doesn't sound terminal (at least based on what I could tell from the video).

FWIW, the best tool you can buy for the money is a mechanic's stethoscope. It allows you to pin down the source of most mechanical noises with ease. Just poke around on the likely suspects with the rod, and when you get on the guilty component, you're really going to know it immediately. Under $4 from Harbor Freight (and it works fine - I have two, "just in case").

https://www.harborfreight.com/mechan...ope-63691.html

 

Did the screw driver to ear trick. Sounds like it’s coming from under the manifold. 🤔

I agree that it doesn’t sound internal. Could a bad engine mount be causing a weird vibration noise through the manifold? Car runs fine. The sound does change pitch with reving up.

Thanks for the response

 

That's a good trick (screwdriver to the ear) though the stethoscope is a LOT better (trust me on that one). You get a lot more nuanced version of the noise that can often help you with the diagnosis, instead of just the location.

It does sound like a mechanical noise, but "lighter" than I'd expect from a motor mount. You could always have a (trustworthy!!!) assistant put the car through P-R-N-D to see if the noise changes. If it does, that would possibly point toward a motor mount (or at least to something that moves when the motor rotates "normally" when put in gear). If the noise doesn't change, look for something else - could be just a loose clamp or a hard plastic part touching something solid.

 

I will give that a try when I get home tonight. It’s. my daughters car we got her for school. So if I don’t figure it out soon I’ll start hearing it lol.

Thanks again

 

Believe it or not it was the alternator ready to rocket its front bearing!!!!


It was brand new and just installed 2 months ago.

Replaced and good as new.

 

Congrats on a successful repair. It wouldn't be the first time a new part failed quickly though - in fact, they're MORE likely to fail than a typical "old part" - engineers describe the statistical curve associated with parts a "bathtub curve" since new parts are more likely to fail, but get progressively less likely to fail for the rest of their "normal lifespan", then get more and more likely to fail (if you plot it, it looks like a bathtub).

This is a prime example of the value of a stethoscope. You just poke the probe around on the likely suspects, and when you got to the alternator, it would be painfully (loudly) obvious.

OTOH, I recently had a case where my stethoscope didn't help much - a buddy with an Audi had a horrible mechanical (I though) squealing coming from the area near the front of the engine. You could literally hear it a block away. I put the 'scope on everything I could think of without ID'ing the problem. On a whim, I popped off the oil fill cap and the noise stopped cold... turns out the problem was a bad PCV valve, and the squealing was actually an air leak that was whistling as air rushed in from the intense vacuum being held inside the engine.

 

Ordered one from Harbor yesterday!!! Thanks for the suggestion.

Got lucky and just decided to pull the belts and see if the noise changed or went away. Sure thing it did.
However I check everything else first thinking there is no way it could be the alternator lol.

Your buddy is is lucky he didn’t blow his cam seals or anything else. It seems to be always something

Thanks for the replies !!!