Sudden Increase In Exhaust Noise

[Carbon VW]

Just to report back…..extra noise disappeared as mysteriously as it appeared after 24hrs.
Dealer checked during first MOT today and reported no fault could be found.
My wife says I have an over active imagination!

I tend to agree with your wife 

[skippy]

Hello all, experienced these symptoms for the first time on my MK7.5 GTI this weekend in almost 6 years of ownership, I am sure it is a regen.

Car was not as smooth running as normal and as per discussion previously, fuel consumption has fallen off a cliff! Most of the running I was in high 20's and only just crept over 30mpg once reaching home.

I had not used the car much during November, 8 miles in 3 weeks I think. Did a decent'ish run today of about 17 miles each way (gap of 4 hours or so between), but the regen operation is still there. Traffic and my route was such I could not get a sustained high's rpm to clear it. Think I need to take it for a blast to complete it, as the car really does not perform any where near as efficiently while performing a regen.

[SRGTD]

Hello all, experienced these symptoms for the first time on my MK7.5 GTI this weekend in almost 6 years of ownership, I am sure it is a regen.

Car was not as smooth running as normal and as per discussion previously, fuel consumption has fallen off a cliff! Most of the running I was in high 20's and only just crept over 30mpg once reaching home.

I had not used the car much during November, 8 miles in 3 weeks I think. Did a decent'ish run today of about 17 miles each way (gap of 4 hours or so between), but the regen operation is still there. Traffic and my route was such I could not get a sustained high's rpm to clear it. Think I need to take it for a blast to complete it, as the car really does not perform any where near as efficiently while performing a regen.

It does sound like a GPF / OPF regeneration. In addition to lumpy running and poor mpg, there are other tell tale signs of a GPF regeneration - outlined in my post (reply #6) in the discussion topic at the link below.

Unlike diesel particulate filters where blast at sustained high rpm’s does help to clear the DPF, IMHO it’s not the best way to clear the GPF in a VAG petrol engined car - the process outlined towards the end of my post (reply #6) in the linked topic has worked for me and for other forum members too.

https://www.golfgtiforum.co.uk/index.php?topic=290349.msg2665390#msg2665390

Also, be aware that if you happen to switch off the engine while a regen is in progress, the regen will recommence during the next (and subsequent) ignition cycle(s) until it’s finished. Therefore, if you’re aware of a regen in progress when you’re nearing the end of your journey IMHO it’s best best to extend your journey so the regen can run its course before switching off your engine.

[skippy]

Thank you so much SRGTD, you always give such a detailed analysis to forum members questions!

I will heed your advice on that one and optimise engine braking. It was a bit strange in that in almost 6 years of ownership, I had yet to experience this. The car tends to sit in the week and gets used on longish runs at the weekends, I try and avoid short stop/start journeys if possible.

We are soon selling my wife’s car (Polo GTI of 2010 vintage) so we have been getting the maximum use out of it for the last time leaving my Golf pretty idle during November. Only yesterday I noticed the increased tickover speed and the obvious increase of resonance from the exhaust!

Thank you so much again for your reply!

[Watts]

Thank you so much SRGTD, you always give such a detailed analysis to forum members questions!

I will heed your advice on that one and optimise engine braking. It was a bit strange in that in almost 6 years of ownership, I had yet to experience this. The car tends to sit in the week and gets used on longish runs at the weekends, I try and avoid short stop/start journeys if possible.

We are soon selling my wife’s car (Polo GTI of 2010 vintage) so we have been getting the maximum use out of it for the last time leaving my Golf pretty idle during November. Only yesterday I noticed the increased tickover speed and the obvious increase of resonance from the exhaust!

Thank you so much again for your reply!

Having heeded SRGTD's advice on regens I can confirm it worked perfectly for me. Spot on advice as usual

[SRGTD]

Thank you so much SRGTD, you always give such a detailed analysis to forum members questions!

I will heed your advice on that one and optimise engine braking. It was a bit strange in that in almost 6 years of ownership, I had yet to experience this. The car tends to sit in the week and gets used on longish runs at the weekends, I try and avoid short stop/start journeys if possible.

We are soon selling my wife’s car (Polo GTI of 2010 vintage) so we have been getting the maximum use out of it for the last time leaving my Golf pretty idle during November. Only yesterday I noticed the increased tickover speed and the obvious increase of resonance from the exhaust!

Thank you so much again for your reply!

You’re very welcome  .

Having heeded SRGTD's advice on regens I can confirm it worked perfectly for me. Spot on advice as usual

Good to hear it worked for you @Watts  .

[skippy]

Thank you very much both, I will report back in a few days time, but confident it will sort it.

I did not really enjoy the driving experience I must admit compared to normal. The power was definitely not as sharp as usual, and seeing the range dropping by 5 mile  increments every few minutes it seemed was alarming!