GTI Engine noises and performance issues

[john896]

Having it in Eco mode all the time on short journeys probably doesn’t help.

Eco mode is a waste of time, just leave it in normal, you won’t see any negative effects on your fuel efficiency

It’s not in eco mode to save fuel. I fill her car up once every 6/7 weeks and it’s only costing about £30/£40 each time with roughly 100/150 miles still displayed on the range so it’s not a cost saving exercise. She doesn’t drive many miles but having the engine in eco mode dampens the throttle response. As she has only been driving since about February it is allowing her to get use to driving and keeping it more smooth. She learnt how to drive in a manual also so this gives her a nice steady pace for getting use to the car without the added fear of pressing the peddle a little too much at junctions or at low speeds. Once she is use to the car and comfortable I’m sure it will end up in normal or sport but at the moment it’s simply not needed for her. After all she’s only drive about 600miles in her life with the rest on the polo driven by myself while she was doing her lessons to run it in.

Only the engine mode is in eco, gearbox is in normal drive, steering normal and suspension is also normal.

[Rosinfield]

As said before, it is what happens if you want the GPF to fill up and cause these problems; just drive only short distances (not good for the car in other respects too) in ECO. Success guaranteed. Imo ECO mode is a shame on the GTI and owners should at least express this feeling by never using it
Mine is in Individual, with sound in ECO (that's the only reasonable eco mode), suspension in Normal, DSG in D and the rest in Sport

[john896]

It’s not really a problem in eco though is it. The gpf will regen no matter how the car is driven so if that is all it needs to do then it’s a simple case of giving the car a run out every once in a while to clear it. It’s just a surprise when she can smell burning and the car feels like it’s dragging so panic mode sets in.

I agree the car is much more fun to drive in sport but as I have been driving for over 20 years and have driven cars with various degrees of power and performance it’s easy for me to drive. However for a new driver who is use to taking it easy in a leaner car the throttle response is a bit too sensitive so eco is a better mode for now.

[lancslad1985]

I could be wrong, but I thought ECO reduced engine braking and let the car coast more. It’s the engine braking that clears the GPF, as this functions completely differently to a dpf which you can just aggressively blast down the motorway to clear.

If it is the case that ECO mode reduces engine braking then this will prevent the car clearing the GPF quickly and would then make it the worst mode to drive the car in. I could be wrong however.

[john896]

The gearbox is in drive not eco so the coasting is not there. If the car was in full eco mode including gearbox then it would coast but it’s not so it doesn’t. She has the car in eco but doesn’t need to select or change any modes when she gets in as it stays in eco with stop/start turned off. The gearbox resets itself to normal though which is fine as she doesn’t want to coast so she doesn’t have to mess with settings each day.

[monkeyhanger]

I could be wrong, but I thought ECO reduced engine braking and let the car coast more. It’s the engine braking that clears the GPF, as this functions completely differently to a dpf which you can just aggressively blast down the motorway to clear.

If it is the case that ECO mode reduces engine braking then this will prevent the car clearing the GPF quickly and would then make it the worst mode to drive the car in. I could be wrong however.

You are right. Engine braking pulls air through the engine that ian't used in combustion of fuel ("motoring") and ends up in the exhaust where the oxygen is available to burn off the soot as CO2.

I have tried to adjust my wife's driving style so that she takes her foot off the accelerator more often.

She gets one every 2k miles after the first one at 5k miles. I get up to speed quickly, anticipate the road ahead well (coming off the gas to match the speed of slower cars ahead, approaching roundabouts etc.), all that helps burn off soot in the GPF.

When you coast, the car is still burning fuel maintaining idle speed, and only pulls through enough air to support the combustion of that fuel.

Coasting is very short-lived anyway unless you're coming down a very long hill with a gradient shallow enough to maintain speed but not gain any. Coming down a steep hill, you'll pick up speed and as soon as you toucb the brakes, the coasting stops.

Eco mode impedes passive GPF regeneration.

If your driving style involves acceleration and braking with no engine braking (like my wife's), passive GPF regen is going to be difficult.

Diesels work differently - they always combust fuel under a large excess of air, so there's always air available to the DPF to combust soot. All a diesel needs the driver to provide to combust soot in the DPF is heat (from a decent length journey at high speeds).

[john896]

Coasting only works if your clutch is disengaged which if the gearbox was in eco you can feel that happening when approaching junctions and taking your foot of the throttle. However her gearbox once again is NOT in eco so engine braking is happening as it would in normal or sport modes. The engine never coasts and does engine brake the same as all other modes do. Eco engine mode simply reduces things like throttle response, air conditioning consumption and possibly reduce top speed. The GPF May need to regen which is fine if it does I will take it out and run it as suggested for 20/30mins accelerating and decelerating between 70 and 60 and see where it goes from there.

[lancslad1985]

I could be wrong, but I thought ECO reduced engine braking and let the car coast more. It’s the engine braking that clears the GPF, as this functions completely differently to a dpf which you can just aggressively blast down the motorway to clear.

If it is the case that ECO mode reduces engine braking then this will prevent the car clearing the GPF quickly and would then make it the worst mode to drive the car in. I could be wrong however.

You are right. Engine braking pulls air through the engine that ian't used in combustion of fuel ("motoring") and ends up in the exhaust where the oxygen is available to burn off the soot as CO2.

I have tried to adjust my wife's driving style so that she takes her foot off the accelerator more often.

She gets one every 2k miles after the first one at 5k miles. I get up to speed quickly, anticipate the road ahead well (coming off the gas to match the speed of slower cars ahead, approaching roundabouts etc.), all that helps burn off soot in the GPF.

When you coast, the car is still burning fuel maintaining idle speed, and only pulls through enough air to support the combustion of that fuel.

Coasting is very short-lived anyway unless you're coming down a very long hill with a gradient shallow enough to maintain speed but not gain any. Coming down a steep hill, you'll pick up speed and as soon as you toucb the brakes, the coasting stops.

Eco mode impedes passive GPF regeneration.

If your driving style involves acceleration and braking with no engine braking (like my wife's), passive GPF regen is going to be difficult.

Diesels work differently - they always combust fuel under a large excess of air, so there's always air available to the DPF to combust soot. All a diesel needs the driver to provide to combust soot in the DPF is heat (from a decent length journey at high speeds).

Cheers monkeyhanger. This will be my first GPF and I tend to drive like you suggest anyway, safely letting the engine brake when approaching roundabouts and junctions. My wife drives like yours however so I’ll have to educate her when she gets her next car.

[ryanponti]

Coasting only works if your clutch is disengaged which if the gearbox was in eco you can feel that happening when approaching junctions and taking your foot of the throttle. However her gearbox once again is NOT in eco so engine braking is happening as it would in normal or sport modes. The engine never coasts and does engine brake the same as all other modes do. Eco engine mode simply reduces things like throttle response, air conditioning consumption and possibly reduce top speed. The GPF May need to regen which is fine if it does I will take it out and run it as suggested for 20/30mins accelerating and decelerating between 70 and 60 and see where it goes from there.

Are you sure you have it in Eco mode then? Every time i have tried mine in eco mode it coasts when there is no throttle input. The coasting is a function of Eco so if its not doing it; it might have an issue?

[sc-red]

Coasting only works if your clutch is disengaged which if the gearbox was in eco you can feel that happening when approaching junctions and taking your foot of the throttle. However her gearbox once again is NOT in eco so engine braking is happening as it would in normal or sport modes. The engine never coasts and does engine brake the same as all other modes do. Eco engine mode simply reduces things like throttle response, air conditioning consumption and possibly reduce top speed. The GPF May need to regen which is fine if it does I will take it out and run it as suggested for 20/30mins accelerating and decelerating between 70 and 60 and see where it goes from there.

Are you sure you have it in Eco mode then? Every time i have tried mine in eco mode it coasts when there is no throttle input. The coasting is a function of Eco so if its not doing it; it might have an issue?

Just to check, when the dash shows the gear you are in, does it show E before the number. My GTI remembers the mode but always starts with the D gear, I need to choose eco before every journey to ensure I’m in the right mode.

[john896]

sc-red, the mrs GTI also defaults the gearbox to D after the engine is switched off and also keeps the engine mode in eco. This never stays in E mode hence why I know it’s never coasting as the gearbox is always in D.

I don’t think there is a fault with this I think it’s probably more to do with the engine trying to warm up efficiently.