Engine Whine

[GTIGuy17]

Hey fam. I've got a 2012 GTI that is making a ridiculous engine whine/howl/screech that started today after I got a car wash. I've attached a video of the noise. My only mods are a Neuspeed intake and a Magnaflow cat back. It idles rough and the ECU revs the engine on it's own. The rev at the 0:25-0:27 mark is the ECU, not my foot. My guess is the turbo is broken or leaking somewhere and its revving the engine to try to make up for the loss in airflow. Maybe? What's weird to me is that the noise stops briefly when I make the left turn from a dead stop. It's not the brakes. 100% coming from the engine somewhere. It happens in N so I know it's not the transmission. 6 speed if it makes a difference. Recently I started burning more oil than usual. Probably at the 1Qt/1k mi mark. Checked the oil and topped it off recently. Level is good. Any help would be greatly appreciated.

Engine whine video

 

[brat_burner]

Take the belt off and turn the pulleys by hand. Also check the alternator pulley closely, it's clutched.... shouldn't be related to getting the car washed tho.

 

[GTIGuy17]

Take the belt off and turn the pulleys by hand. Also check the alternator pulley closely, it's clutched.... shouldn't be related to getting the car washed tho.

If one is messed up it would feel chunky or granular. Bad bearings? How would a clutched pulley feel compared to regular one? Just harder to turn? I replaced the alternator myself about 6 months ago. Not OEM. Wonder if that could be it. I did look at the serpentine belt earlier for slippage at idle but didn't see any. I'm guessing that's more tensioner related than bad pulley? Thanks for the help!

 

[brat_burner]

Yes, or possibly completely seized making that much noise ha. The clutched pulley will spin one way and lock in the other(you'll have to counter hold the center section) Yea if the belt isn't super loose(tensioner) or you don't see anything super obvious just loosen it up and double check everything.

Oh and no harm in starting the car with the belt off momentarily to see if the noise is still there. Just won't be charging

 

[GTIGuy17]

Man seized would be great for finding the culprit lol. I will check on these when my filter dries and I put it back on the intake. Appreciate the help. I'll let you know what I find.

 

[GTIGuy17]

UPDATE: Removed the serpentine belt completely and checked the alternator and a/c compressor pulleys (guessing that's all that's hooked up to it) and nothing seemed to rotate abnormally. Ran the engine with the belt completely off and had no loud squeal like in the first video. I should mention that it took a minute of driving around the block to get that crazy loud squeal to start happening. There is a really high pitched noise (unrelated to the squeal in the first video... I think) coming from the engine bay as well. It's easily audible in this video here. Reminds me of the mosquito ringtone from back in the early 2000s.This video was made with the serpentine belt completely off. Does the throttle body make noise when it's failing? It sounds like it coming from that area. Would also explain the rough idle.

 

[GTIGuy17]

Update for those who are interested. Got codes read. Threw a bunch of misfires as well as p0507 and p2279. Found a video on youtube showing a test for the PCV valve on a BMW. Guy had the same whistle, popped out his dipstick while it was running an the whistle went away. I tried that and boom, just the sounds of valves opening and closing. I replaced the PCV today and took it for a test drive. She's alive again!

TLDR: Really loud whistle coming from your engine bay? Pull the dipstick out. If the sound goes away, it's probably your PCV

 

[brat_burner]

Update for those who are interested. Got codes read. Threw a bunch of misfires as well as p0507 and p2279. Found a video on youtube showing a test for the PCV valve on a BMW. Guy had the same whistle, popped out his dipstick while it was running an the whistle went away. I tried that and boom, just the sounds of valves opening and closing. I replaced the PCV today and took it for a test drive. She's alive again!

TLDR: Really loud whistle coming from your engine bay? Pull the dipstick out. If the sound goes away, it's probably your PCV

Nice! Good to know, seen something like that before but wasn't that LOUD!