2x 2015 Jettas: 1 quiet cabin, 1 noisy. 6 days left on warranty. what to check?

Warranty expires 6/2/2020 then this will be on my dime!

I have a 2015 Jetta TDI with 30k and it seems to have more unmuffled "diesel" engine noise than when it I first drove it home from the dealer in June 2017. This is noticeable when running in a garage, or idling in traffic at an intersection, etc. It's been monkeyed with by one dealer numerous times, steering column twice, clockspring, transmission flywheel twice, sunroof motor/glass/frame. Over 60 total days in service, mostly for repeat jobs and dealer incompetence.

I also have a "spare" new 2015 Jetta TDI which I just put into use, it has only 1,500 miles on the clock. Never been serviced at a dealer, and still quiet as can be--can't tell it is a diesel when sitting inside. My wife drove this the other day and she came back saying how awesome and quiet the car is and how much she loves it.

They are on opposite sides of the country so I can't bring both to the dealer to compare side by side. (Ok--could, but won't

First, I'd love some feedback from other owners or techs on tdiclub to see if their car had more pronounced noise at 30k than when it was new?

Second, my thought is the dealer contributed to this noise by leaving something missing or damaging soundproofing, missing or not tightening clips, etc. The same dealer spilled adblue on both service visits, and left oil stains on the engine cover near the fill cap.

Steps I've taken:

-Visually checked screws on bottom skidplate with acoustic material
-Purchased a sound meter from Amazon and gotten mostly similar readings from inside both cars, under the engine, an under the hood. It's almost that the tone is different, not not the overall volume.

- Today I just took it to a competing dealer, with **6** days left on the factory warranty and offered them a tip if they could find anything wrong. They did not. It's going back Friday for a keyfob, screw for dash rattle at 2k rpm, and to fix or replace a rattle in the glovebox center console/armrest.

you still have the engine cover right ?

Also, at idle, are the vibrations similar on both ? look at the engine at idle.

Mine is quiet, but I sure can tell it's a diesel. In my wife's Elantra, I have to look at the tachometer to make sure the engine is on.

On the 'skid' plate, is the insulation still there and not soaked with oil ?

There is also a shroud cover on the oil pan that serves as noise insulation. Check if it is still there.

Hard to believe that car has been so unreliable.

ticaf said:

There is also a shroud cover on the oil pan that serves as noise insulation. Check if it is still there.

Click to expand...

The shroud is probably still there, but the foam insulation inside it has most likely absorbed a ton of oil that migrates from the pan drain hole during oil changes if the oil is drained conventionally and not vacuumed from above or if a drain valve has not been installed.

The oil absorption compromises the sound insulating properties of the foam. I couldn't believe how much oil I could squeeze out of the foam after the dealer's one and only oil change. Needless to say, I remove the shroud before I drain the oil now.

@ticaf & rip_tdi

engine rpm are similar for both cars, engine covers present on both.

I'll have dealer check the oil pan shroud and if that or the acoustic insulation is soaked with oil.

It wouldn't be a shock if I find out dealer #1 who left oil marks on engine cover spilled enough to fall onto insulation.