What else could go wrong? Loud sound.

[robertn78]

I have a 1999 Merc Mount 2x4 with 5.0. It is late and hot here in Vegas and the engine bay was almost intolerably hot, so didn't get too far with it. There is a whine / Humming sound coming from the drivers sideish engine bay. I checked the A/C compressor, Power Steering, center Idler, Water Pump, etc. Could not reach the tensioner pulley with my stethoscope. Any thoughts where this noise is coming from. I made a very amateur video that may help. I am also having a Code P0455. Is there a valve/actuator or a clog that could be associated with this?

Sound is similar to a bad fuel pump noise. There is none in the engine bay, right?


Sound changing from left to right is probably me holding the cell phone over the mic.

 

[RobertFord]

Sounds like a vacuum hose not being connected, but I could very well be wrong...

 

[koda2000]

i'd pull the belt and see if the noise goes away. if so, check the idler and tensioner pulleys for play and smooth operation. if they're okay check the a/c compressor pulley (could be the bearing is going bad) again, check it for play and smooth op. if that's okay, the only thing left on that side of the motor is the power steering pump.

tip: make a drawing of the belt routing before you remove it. getting it off is pretty easy. reinstalling it can be a PITA. if it's been a while since you've changed the belt, this would be the time to put a new one on.

 

[robertn78]

The noise has stopped, on its own. I will have to do some diagnosing on the EVAP system this week end. Thanks for the input guys!

 

[koda2000]

there's something associated with the evap system that lives in the area where you're hearing the sound. there's a hose that runs from the evap system, in ther rear, to a connection under the battery. i'm not sure if the "purge" valve is located at this location, but i think it might be. if the valve, or the hose, has an issue it would generate the P0455 code you're getting and the noise.

 

[robertn78]

Sorry guys, I thought my wife said that the sound had stopped. I guess I listen to her instead of hear her. I will keep you up to date! Thanks guys.

 

[robertn78]

Found it.

This is the Hose between the Canister Purge Valve and the Intake. That was the exact code the car had. Gross leak in Evap system. Thanks guys!!! All fixed.