Possible cause of loud engine droning

[fruitcakesa]

My wife mentioned, after a long highway run in the 04, that it was definitely louder than the other cars, almost an exhaust leak.
I went for a drive and it did sound dronish to me but I can't say it that it hadn't before and I just hadn't noticed.
I jacked up the car tonight and looked over the exhaust system which appears to be a stock OE setup and it is solid as far as I could tell.
Now my question is this:
Since this car has a VNT17, a Kerma tune and an EGR delete, would that combo of mods make the car drone?
It isn't painfully loud but it is noticeable and if it is remediable I would like to know.

 

[turbobrick240]

You may want to check around the exhaust manifold for leaks. I don't think you should have much/any drone with a non leaking factory exhaust. Kind of a subjective thing though.

 

[fruitcakesa]

You may want to check around the exhaust manifold for leaks. I don't think you should have much/any drone with a non leaking factory exhaust. Kind of a subjective thing though.

I know i need to get under it while it's running to confirm.

 

[squishbang]

If the noise is loudest from the intake (louder after removing top half of air cleaner housing) the camshaft may have a worn lobe.

 

[Wilkins]

Check between the flex pipe and cat, I had a crack in that area. I think a PD is quieter than an ALH under light loads.

 

[maxmoo]

also, make sure that no part of the exhaust is contacting the body anywhere, except by rubber mounts.
A bad rear wheel bearing can also sound like exhaust drone sometimes.

 

[KLXD]

Another vote for a cam problem.

Or a rear window partially open.

 

[RacerTodd]

I know i need to get under it while it's running to confirm.

I had an exhaust leak on my old Golf. I wanted to find out where exactly the leak was so I could replace the correct part.

Here is a technique that worked very well.

Car up on jackstands, high enough that I could get under it and access the exhaust manifold/downpipe area.

I got a length of regular vacuum hose and held one end tight to one ear. The other ear got an earplug to block sound from that ear.

Started the engine and crawled underneath. Pointed the free end of the vacuum hose at various common leak points. I could easily hear the exact point where exhaust gases were leaking out when the hose was pointed right at the leak. Move the hose a few degrees away, sound went away. Very accurate, which helped pinpoint the leak.

The key is blocking all sound except that coming from the hose. The hose has to be held tightly to the ear. In lieu of an earplug in the un-used ear, you can use a finger.

A mechanics stethoscope can be used. I have one that has the tubes ending in a solid probe. The probe can be removed and it then functions like my vacuum hose version.

 

[fruitcakesa]

Finally got the car up and the skid plate off.
First thing I notice is fresh oil coating the turbo to EGR pipe.
When I push/pull on the hose it moves in and out maybe 3/16" +_
Would this indicate worn o-rings and I am getting oil leakage from around the coupling and also be causing the excess noise?
The exhaust feels tight and I tried the tube/ear trick but my poor hearing could not detect any sound differences.

 

[JB05]

No cracks in the EGR cooler pipes? No missing bracket on the left side pipe from a recall?

 

[fruitcakesa]

I was incorrect which pipe was loose, it is the turbo to EGR pipe from under the turbo.
Did not check EGR cooler

 

[turbobrick240]

Yeah, that sounds like the culprit.

 

[BuzzKen]

http://http://www.fixmyvw.com/the-doggie-collar-for-bew-engines/