"Choking“ exhaust while reversing

"Choking“ exhaust while reversing

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AyOneTen

Original Poster:

35 posts

31 months

Saturday 25th November 2023
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I have noticed something peculiar in the last few month on my April 2022 A110 GT (300HP) that seems to happen almost exclusively in one parking garage at my workplace. Maybe somebody has an idea.

After a 16km commute to work (it‘s my daily driver) I park it in the garage and when I reverse out of my parking spaces the exhaust sounds as it is almost choking because it cannot blow the fumes out and power delivery on the throttle is almost non existent, the engine seems to be almost stalling for a few seconds but then everything goes back to normal.

It does not seem to happen (or at least almost never) when I start and reverse out of other parking spaces.
No warning lamps go on and I have not noticed anything else.

Has anybody experienced the same or does anybody have any idea what this issue may be related to?

Many Thanks.

RikkertBiemans

65 posts

26 months

Saturday 25th November 2023
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Start/Stop?

LE62NDE

350 posts

27 months

Saturday 25th November 2023
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Sports exhaust flap actuator? My MY22 Legende sounds like it has an old-fashioned blowing exhaust on start-up, but then the flap closes and everything settles to a level tickover. If the flap doesn't close, that might effect the extraction of exhaust gases?

Olivera

7,671 posts

246 months

Saturday 25th November 2023
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Beginnings of fuel pump failure? I would bet it has nothing to do with the exhaust.

AyOneTen

Original Poster:

35 posts

31 months

Sunday 26th November 2023
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Thanks for the comments so far.

So I do have the Sports Exhaust but usually get in and out of the parking space with the valve closed in Normal Mode.

In Normal Mode usefully I have Start Stop active, but the engine starts up fine but only when I apply the throttle the „exhaust choking“ happens for a few seconds and power delivery is very slow before it normalizes after a few seconds together with the exhaust.

I was worried about fuel pump (so far there has not been a recall issued in Germany interestingly enough), but then why would it only happen in the parking garage at my workplace? It‘s an open parking garage with direct ventilation from outside so not an underground parking garage without fresh air supply.

bcr5784

7,182 posts

152 months

Sunday 26th November 2023
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I don't know this for a fact, but I would suspect that the exhaust valve is actuated on startup regardless of Sport/Normal to stop it sticking if you always drive in Normal.

kdempsie

98 posts

176 months

Sunday 26th November 2023
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Hi,

I have had something similar over the last year or so across two different A110s. Perhaps it’s similar but I thought of it slightly differently than you describe it. My car is hesitant on the throttle almost like or might stall or the electronic throttle is not working , I take my foot off the pedal then reapply it and everything is normal. It only happens on first start up occasionally and always works normally afterwards, so I haven’t worried about it too much.

I am due to get a new fuel pump in the recall so I will update this post if I notice any change afterwards.

Keith

bcr5784

7,182 posts

152 months

Sunday 26th November 2023
quotequote all
kdempsie said:
Hi,

I have had something similar over the last year or so across two different A110s. Perhaps it’s similar but I thought of it slightly differently than you describe it. My car is hesitant on the throttle almost like or might stall or the electronic throttle is not working , I take my foot off the pedal then reapply it and everything is normal. It only happens on first start up occasionally and always works normally afterwards, so I haven’t worried about it too much.

I am due to get a new fuel pump in the recall so I will update this post if I notice any change afterwards.

Keith
Mine does that occasionally too - and sometimes does actually stall. Like you it always works fine afterwards so I don't worry about it.

Colin P

459 posts

150 months

Sunday 26th November 2023
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Is this perhaps a tickover issue. Mine runs a little lumpy when really cold in normal as the tickover is only 750rpm, as opposed to 1000 in sport. I think 750 is a touch too low.

Perhaps try putting it into sport before you reverse out next time and see if it makes a difference.

CliveJ7

65 posts

70 months

Sunday 26th November 2023
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Do you reverse out more or less straight away after starting when cold?
As you're probably aware there's a choke which you can hear coming off after about 30 seconds, when the rather lumpy tick over smooths out.
I always wait for the choke to come off before moving and then warm it up a little more before driving.
IMHO that makes for a smoother getaway as well as allowing the oil to circulate round the turbo/engine more).

AyOneTen

Original Poster:

35 posts

31 months

Sunday 26th November 2023
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Good points guys.

Well the thing I do not understand that it does almost exclusively happen at my workplace parking garage and nearly nowhere else. Both parking spots (Work and private) I reverse out of the same way so I do not really get why one makes issues and the other does not. I may try to film it tomorrow.

As you guys say it seems like the car is close to stalling once I reverse and for a few seconds once I put it from reverse into drive.
The issue started in normal summer/autumn temperatures. SO outside temperature alone might also not be the solution.

Olivera

7,671 posts

246 months

Sunday 26th November 2023
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CliveJ7 said:
As you're probably aware there's a choke which you can hear coming off after about 30 seconds, when the rather lumpy tick over smooths out.
Yeah it's probably just this. The actual purpose of this cold start map is to quickly heat the catalytic converter for emissions reasons, usually accomplished by fully opening the turbo wastegate and overfuelling for about 30 seconds. In my experience in other cars (Mini, BMW) you can get a jerky throttle occasionally during this period.

Zarco

18,492 posts

216 months

Monday 27th November 2023
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Olivera said:
CliveJ7 said:
As you're probably aware there's a choke which you can hear coming off after about 30 seconds, when the rather lumpy tick over smooths out.
Yeah it's probably just this. The actual purpose of this cold start map is to quickly heat the catalytic converter for emissions reasons, usually accomplished by fully opening the turbo wastegate and overfuelling for about 30 seconds. In my experience in other cars (Mini, BMW) you can get a jerky throttle occasionally during this period.
My gut feel too. All Renaults I've had (F4RT engines) have sometimes been a bit 'fluffy' from cold on a part throttle.

AyOneTen

Original Poster:

35 posts

31 months

Monday 27th November 2023
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Not really convinced this is the reason as I wanted to film it today and it was close to 0°C and it did not do the choking today while it started doing it regularly in the summer. Not sure it has to do with ambient and engine temperature then,