2010 TDI Golf Wagon - low rpm resonance

My friend used to have an old Golf hatchback so I remember that it was impossible to drive it with just the rear windows open.

Our other car is a Malibu Maxx station wagon. So, I always have to crack open the front windows if I need to have the rear windows lowered.

The humming resonance with 2010 is differrent though. This occurs when both the sunroof and all windows are fully closed. As a matter of fact it's actually a bit better when the windows are slightly open. Unfortunately it's getting colder here, and when it rains driving with open windows is not an option either.

One thing I really hope for is that this issue is not the result of incomplete design testing by VW. After all 2010 TDI Golf Wagon is generation MKV.2. MKVI front end married to MKV back end. Let it not be that someone forgot to test drive 2010 Golf Wagon with a diesel in the design center, and all tests were done with 2.5L gas engine. This would be a disaster for VW.

Sorry to be so negative, but after all I got a brand-spanking new car for tons of money ($37,500) but it sounds worse than an econo-box for $12,500.

Possible source of noise - same as my 2010 TDI SportWagon

We purchased a 2010 Jetta SportWagon TDI about two weeks ago. When the sales person brought the car around for us I heard a noise outside like a vibration. The sales person also heard the noise and assured us it could be fixed but since it was afte hours, we'd have to come back.

While driving the car home the noise would come and go; more noticible between 30-35 MPH. We took the car back and the technician found a broken plastic guard under the engine compartment. They ordered a replacement and said not to worry; it was safe to drive.

When the replacement part was installed, the noise returned. The technician went on the dealer's lot and found two more 2010 TDI's and compared them. To his surprise, neither had the part installed. Here's the exact words from the dealer: "It was a drive shaft heat shield. Needed on gasoline engines but not diesels."

I never saw the part as my wife took it back for repairs. If it happened to mine, it could be the same on yours. Good luck!

Hm....is the heat shield a plastic half circle that went around the drive axle? This is a CV boot heat shield. Without it, the CV boot is exposed to more heat and it can crack early. Strange that it wouldn't be on the other 2010 TDIs but I would want one. Here is a pic showing the heat shield on a mk4 TDI.

Can you take a pic of the broken part? It's not the suspension blockers?

Update: you told me the dealer said it was VW# 1J0 407 721 C (for the searchers) 1J0-407-721-C , 1J0407721C . This is shown for all BRM and CBEA engine TDI. This is all 2005.5-2006 and 2009 TDI. It's possible they had a rolling change to remove this in 2010 that is not reflected in the parts catalog but I would be very upset if this is true because this shield helps keep the CV boots in good shape. And there are also mystery non-existent parts in the parts catalog or parts shown that aren't on the car. So while they could be correct, your car had one and the parts catalog shows one. Here is a part diagram showing the shield. A similar boot (the one pictured in a previous post) was added to all 98-2005 TDI and is helpful for the earlier 96-98 TDI in preventing the CV boots from drying out.



The ticket you sent me said ""Verified complaint; found noise coming from heat shield rubbing on CV Flange. Replaced heat shield - found same problem. Open VTA ticket 527678 looked at two stock TDI - did not have shield, Found shield does not belong on vehicle. Removed; noise gone."" Can anyone else confirm the presence of a heat shield?

That reminds me of this joke:
Customer complaint: Evidence of leak under right side of car.
Mechanics Solution: Evidence removed.

Complaint: Dead bugs on windshield.
Mechanics Solution: Live bugs on back-order.

Complaint: Engine missing.
Mechanics Solution: Engine found under hood after brief search.

Complaint: Car handles funny.
Mechanics Solution: Car warned to stand up straight, wipe that smirk off, and be serious.

This resonance is a 'feature'. Our 2010 TDI Jetta sedan had it. I said 'had'; that resonance plus the clacking between gear changes (6pd manual), both of which the dealer said were 'normal', drove me to get rid of it after 7K miles. (The unusually jouncy-bouncy ride--so much different from my JSW that I thought it had to be a defect also--and lumbar support that evaporated on long drives didn't help either.)

I've driven several 2011 JSW and Golf TDIs with MT. All exhibit the same behavior albeit the Golfs, for whatever reason, are significantly better in both departments, and probably passable. (Haven't driven any 2012s yet.)

When you are lugging this engine, you know it. There IS a difference between this resonance and lugging. This reasonance disappears below about 1050 rpm. You can accelerate gradually off idle in first and be fine until you hit 1050, then not fine until after 1300-1350. Resonance. Period.

And for those who think that this is too low of an RPM to drive the car at, think again. Watch the instantaneous fuel economy and downshift one gear to bring the RPMs up a couple hundred and out of resonance band. Instantaneous mileage drops a couple of MPG after you adjust throttle to keep the same speed. In my case, there is a SLIGHT grade signed at 45mph that I drive regularly--it's about a half mile long and comes off of a flat stretch signed at 45 also. On my 2010 TDI, 6th gear would put me right smack dab in the resonance band at 45. Holding 45 and changing to the grade from the flat stretch added enough load to the engine that the resonance was unbearable. But downshifting to 5th dropped my mpgs from 42-43 to about 38 when running the grade at 45.

BTW--I've noticed that my '09 JSW SEL, with the 2L turbo gas engine, has the same resonance in almost the exact same rpm band. It's barely noticeable in the gasser, but there. Not surprising, as I believe the two engines probably share a lot of parts--and design philosophy--south of the head.

The old 1.9 in my '02 Golf TDI does not have this vice. (It has more diesel detonation noise to make up for it) But, at 50-55mpg each and every tank, I think I can be happy enough with my '02 until-if-or-when VW fixes things on it's new 'miracle' TDI--even if I'm not as zippy as the new Golfs. Besides, my rear seats fold flat and solid, like a wagon's--one of the many useful features VW has gotten rid of on the Golf over the generations. And the fixed lumbar support in the '02's front seats is superior to the adjustable lumbar in any Mk5-even the power lumbar in my JSW SEL.

Maybe I'll keep the '02 forever. And anyway, I seem to be one of the few owners of Mk4s that actually likes the sound of the factory 'Monsoon' CD/radio...