Loud noise in 6th gear between 100 - 115 km/h

[SkodaSponge]

Hello, since I purchased my 09 Octy 4x4 (2.0 TDI estate) I've had a weird issue. Owned it for a year now.

 

When I'm on the highway, and I want to accelerate from a 90 zone into a 130 zone I have this problem:

 

When I reach about 105 km/h and push through 115km/h there is a loud droning noise coming from the middle/rear of the car (or so it seems to me).

 

Once I get to 115km/h the sound disappears. I don't let off the fuel, or press the clutch or anything. I just keep accelerating and it goes away.

 

There is no vibration associated with the noise, it's just really loud until I push through it.

 

It does seem like of I'm not accelerating as quickly the sound isn't as bad.

 

I've been trying to search for similar threads but can't find someone describing the same thing. If someone has an idea what this is, I look forward to your reply.

 

Ps. I know diesels are generally louder cars but this part seems a bit weird to me. 

[DataflowDesign]

Might be worth swapping the tyres front to rear to see if this changes the location of the noise.  I had some very noisy tyres on the back of my vrs estate. Once the fault was isolated I  changed out the tyres and the noise went.  Note the noise on mine was consistent from about 20 mph on up until about 70 when the general road noise drowned it out.

 

Good luck with yours!

Edited 25 October, 2018 by DataflowDesign

[Anddenton]

My scout tends to do something similar and I'm pretty sure it's the engine note changing through the exhaust system

[Ootohere]

?

Has the Haldex had scheduled servicing / oil changed, and when was that last done?

[SkodaSponge]

Thank you for the quick replies.

@DataflowDesign I can try to swap the wheels rear to back to see if it makes a difference. However, I've changed summers to winters to summers again over the last year and the sound never changed.

@Offski Regarding the Haldex, the oil was changed at the first suggested interval, but the second service is over due by a couple thousand kilometers. I can get the exact kilometers/dates later.

I understand the mention about the engine note changing through the exhaust system, but Scouts also have the Haldex system correct? Therefore the Haldex service comes up again, have you done it @Anddenton?

[Ootohere]

?

What schedule are you going by with the Haldex, 48,000 km or 3 years?

[SkodaSponge]

@Offski sorry for any confusion. I looked up the service records:

 

Haldex oil changed in 2014 at 114 142 km. 

 

That's the only time it's been changed. Also I don't see anything about the Haldex filter getting changed during that service.

 

All the service records are in Czech.. I'm using Google to translate but when there is a part # it's easy to look it up and see what's been changed/used.

[Ootohere]

Not good.  Best get that done.

[twostrokemick]

When the haldex is been serviced get the fluid in the near diff changed also. Be sure your mechanic also changes the haldex filter.  If going to a skoda garage do not assume that they are aware of the requirement to change this filter.

 

Tsm

[Anddenton]

18 hours ago, SkodaSponge said:

I understand the mention about the engine note changing through the exhaust system, but Scouts also have the Haldex system correct? Therefore the Haldex service comes up again, have you done it @Anddenton?

Haldex and rear diff oil has been changed every 40k miles on mine, no problems with 4x4 system. Pretty sure the noise on mine is exhaust note, almost as if a valve is opening (EGR or something to do with turbo?) its not the kind of rumble you would associate with a failed mechanical coupling and has been noticeable for at least 100k miles now.

[drmike]

I get exactly the same thing on my scout. I agree that it sounds like it should be exhaust related - mine fell off on a French autoroute last year and has been welded back on. I tend to just drive round it (change down a gear and it's fine). My Haldex has been serviced as per instructions.

I did read something about a rubber prop shaft coupling wearing and causing something similar on Audi TT's (same 4x4 system, give or take a generation of Haldex).

The car's only worth about 1500 quid now, so I'm not going to spend loads solving it!

[Anddenton]

10 hours ago, drmike said:

 

I did read something about a rubber prop shaft coupling wearing and causing something similar on Audi TT's (same 4x4 system, give or take a generation of Haldex).

The propshaft coupling on mine does have an issue where the metal ring around the outside has parted company with the rubber allowing it to move slightly laterally where it would catch on a heat shield making a grinding noise when breaking. I have bodged it back together with some metal ties so I believe it is still doing it's job all be it maybe not quite so efficiently, but I don't believe this to be the cause of any adverse noise.