S6Express

Ever since I took the car in for my fuel line recall and had all the updates done to it I've had a low purring sound coming from the engine bay at low RPMs. It sounds like it's coming from the passenger side. Even my wife heard it the other day and asked about it - and she has no ear for car related noises.

Anyone ever had this? It's kind of annoying.

Delurker

Are you missing any cats?

S6Express

I don't own any cats and when I took a look under the hood no one jumped out.

snagitseven

Is it RPM related. i.e. changes with revs? If not, it might be heater fan related.

S6Express

It does. However when the RPMS go beyond, IDK, about 2000 the pulses are too fast and no longer audible. It also does it intermittently. When the cooling fan is on I can't hear it. I haven't used the heater this year, it's barely been below 70 deg so far in South Florida.

snagitseven

A/C fan bearings can also make weird noises but if it's directly related to RPM, it's something else. If you have a VCDS, you could run a scan and see if something shows up. Could be anything - from a defective belt to a valve issue.

gatorguy7

Hilarious

tenspeed

The alternator, serpentine belt, belt tensioner and idler roll are all down low on the passenger side of the engine. It could be a roller bearing or the alternator is making noise due to the increased load at low RPMs.

Ordinarily I would say to remove the belt to see if the noise is internal or external but it doesn't look too easy to remove. It appears that there is an adjuster on the bottom side of the tensioner assembly. They might be able to tighten/loosen to see if the noise changes.

S6Express

UPDATE: Just picked up the car from the dealer. Apparently when they performed the fuel line recall something didn't go back in right. The repair sheet claims they "removed, replaced, and refitted the fuel line bracket, rattling was coming from the fuel line rubbing against the fuel line bracket." Shows they replaced a bracket and a couple of clips.

Richard Solomon

Well done! Now hopefully the only purring is that of 4 contented liters of pure automotive happiness!