Help identifying engine sound
Thread Starter
Drifting
Joined: Jul 2012
Posts: 1,255
Likes: 297
From: Slovenia, EU
2017 C3 of Year Finalist
Help identifying engine sound
Hi,
I have this hissing sound coming from the engine for couple of years now. I don't know what it is.
No problems with the engine or anything else. The sound is only on the driver side of the engine.
If anyone has any suggestions on the source of the sound please post them.
Thanks!
I have this hissing sound coming from the engine for couple of years now. I don't know what it is.
No problems with the engine or anything else. The sound is only on the driver side of the engine.
If anyone has any suggestions on the source of the sound please post them.
Thanks!
Pro
Joined: Mar 2014
Posts: 529
Likes: 113
From: Texas
Obsessed
Joined: Apr 2019
Posts: 627
Likes: 394
From: Valencia, Spain
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
Usually a hissing sound means a vacuum leak or line got disconnected... I’m no expert though...
Safety Car
Joined: Apr 2006
Posts: 4,057
Likes: 421
From: BC
Start it and let it run for a min. or so. Shut it off, wait about 60 seconds then pull the headlight switch (or wiper door switch if you have one) to see if the doors go up. If they don't, you have a good size vacuum leak. Then check the hose and fittings to the brake booster. After that look for exhaust leaks like a cracked exhaust manifold, bad gaskets or the donuts between the manifolds and pipes.
