Weird engine noise

[mpieklik]

Hey everyone.
After changing the valve cover gaskets and the alternator on my 2006 4.4 N62 motor, there is a weird noise on the passenger side towards the front. It sounds like cshh cshh cshh...and changes frequency with engine speed. It seems to be very quiet at startup when the engine is cold, but shows up a minute or so after the engine has been running at idle. Also it seems to go away sometimes after the motor is hot.

Here is a recording with minimal noise
No Noise - YouTube

Here is with the noise
Noise - YouTube

Anyone have an idea what it could be?

[steelheader]

Most likely your air pump?There are little rubber gromets that age and you might of bumped them?

[mpieklik]

Originally Posted by steelheader

Most likely your air pump?There are little rubber gromets that age and you might of bumped them?

Thanks for the input, I'll check it out.

Matt

[mpieklik]

Originally Posted by steelheader View Post
Most likely your air pump?There are little rubber gromets that age and you might of bumped them?

Are you talking about the vacuum pump or the secondary air pump? I think the secondary air pump is electrically driven and not tied to the engine RPM which this specific noise definitely is.
Please let me know if I'm misunderstanding...

Matt

[steelheader]

If its coming from that corner?Right under the vc is the timing chain tensioner?

[mpieklik]

Yes, the tensioner is right there. I looked at it before I put the valve cover back on and it appeared to be fine, no excessive wear that I could see. The noise has gone away at this point...not sure if that is a good or bad thing...