I changed my valve cover gasket yesterday and took a short drive which unfortunately led me to some street drag races. I had 3 races with a few friends and when I got home I heard this sound. Merc engine sound - YouTube can anyone diagnose it? It sounds like a tooting sound I guess..? You can hear the valve train and then another sound. It can be heard best in the last second of the vid. Excuse for the orange silicone. I need a new intake.. I got it stuck on the throttle.

 

Not sure exactly what sound you are talking about..I Did hear a pop sound and then some air flow noise. Sounds like you have a hose off or some vacuum line off. What about the hoses that go to the valve cover it self? Just sounds like you have some sort of air or vacuum leak.

 

The air sound is the cooling fan running. I'm talking about the diesel sounding pop sound. I had a error code that said I had a small vacuum leak. I cleared it a mth ago tightened my fuel cap and it never came back. How long does it take for the car to read a fault?

 

I would make sure all of your spark plug wires are in the correct position. they need to click into place. make sure that you wires are in the correct position on spark plug 1 and spark plug 2.
Right at 22 seconds there is a pop sound with air rushing... that sounds rather loud.. overall the engine that sounds normal to me..

 

I checked the wires and even pulled the valve cover off again to check the valve train. Everything looks normal to the eye. The pop sound is my hand hitting the mic and the blowing sound is the cooling fan running. What about a vacuum leak? I had a error code trip stating that I had a evap leak. I cleared it and tightened my cap and it's been a few weeks since it came on. I've heard vacuum leaks can damage the engine.