GolfGTIforum.co.uk
Model specific boards => Golf mk7 => Topic started by: P6GTD on 07 February 2022, 19:29
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My 7.5 Performance is coming up for 3 years and 23,000 miles. Had a minor service three weeks ago.
Has run faultlessly from new.
This week, without warning, the exhaust note “seems” to have become louder to the point where it almost sounds like cars used to when there was a hole in the silencer.
Obviously, I am well used to the sound of a 7.5 P both when cold and hot. This just seems to have been magnified for no obvious reason.
The car was one of the first built with the GPF fitted.
Any ideas or similar experiences?
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Possible GPF regen going on? (If GPF’s regen? - my wife’s Polo has a DPF and that makes a right din when it regens)
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I’ve never had a DPF regen in 3 years from new despite many journeys being short. Unlike in my VAG diesel days when regens were very obvious when they happened.
And my present noise increase doesn’t share any of the characteristic sounds of a DPF one.
I don’t even know if GPFs do regens at all…….anybody??
Incidentally, with the GPF my exhaust pipes and tips are as clean as the day the car was bought new. V impressive compared to my Mk7 GTI 220 where the pipes were always dirty.
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Sorry, that first sentence in the last post should have said GPF, not DPF…..
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I think I've had two, pulled up on the drive after the crawl home and the fans were going mad plus it was pumping red hot air out of the wheel arches almost as if it I'd been trashing it.
I can only think it was doing a regen.
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Sure it isn't the soundkator playing up?
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I physically unplugged the device the first week of ownership.
No this is noisy from the outside and inside.
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Gpf doesn't do an active regen like a dpf does.
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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!
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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!
@P6GTD; My money would be on your car’s GPF / OPF performing a regeneration - see discussion thread at the link below;
https://www.golfgtiforum.co.uk/index.php?topic=288470.msg2648053#msg2648053
My reply #8 in that discussion thread lists the symptoms that Polo GTI owners have experienced during the GPF / OPF regeneration, and the symptoms listed by @Rudedog in the original post in that thread are pretty much the same. I don’t think the symptoms @Rudedog listed in their post were connected with their thermostat housing being changed:- IMHO it was purely a coincidence that their car’s GPF / OPF went through the regen process the day after the new thermostat housing was fitted.
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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 :grin: :grin: :grin:
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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.
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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.
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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!
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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 :smiley:
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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 :smiley:.
Having heeded SRGTD's advice on regens I can confirm it worked perfectly for me. Spot on advice as usual :smiley:
Good to hear it worked for you @Watts :smiley:.
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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!
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Hello SRGTD & Watts,
I can confirm that your solution to the exhaust noise increase (caused by the active regeneration) was successful and mpg has returned back to normal.
Took the car for a longer run last Sunday and for me at least, I was a bit more aggressive on the downshift to get the revs up. I am very mechanically sympathetic normally and tend to not venture too far up the rev range.
It did take quite a while to clear, but the overall average mpg always remained low anyway, but I saw it creep up to 34mpg at the end of the run which was an improvement. Took it out tonight and almost without trying I was up to 43mpg!
It is due for service soon, and suspected the garage may have done an Italian tuneup for me to clear it! :laugh:
Thank you very much again for your responses!
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Great stuff! :smiley: