Hi All just joined and first thread. I have a Leon fr 1.4 tsi 150 2016 mk3, put simply it switches to 2 cylinder mode fine but after a say 5 mins in this mode when switching back to 4 cylinders a noticeable puff of smoke is seen, but if switching back after running in 2 cylinder for a short time nothing. It doesnāt do this accelerating with 4 cylinders even after 5 min delay. Any ideas please?
Interesting fault smokes when eco mode switches off help please. Updated.š
- Thread starter Jason2023
- Start date
It's just oil accumulating in the 2 unused cylinders, that's being burnt off when they fire back up. Not a fault, just a consequence of what is a silly design IMO.
It was probably another case of it allowing VW to claim better emissions under some obscure test conditions, but in the real world it does nothing. I can't imagine those big puffs of oil do the life of you catalytic convertor any favours either. If you have an option to keep it in 4 cylinder mode all the time, i would definitely recommend doing that.
No worries mate, welcome to the forum btw too.
If continual 4 cylinder is known to cause other issues, then i'd just stick with letting it do what it wants to do. I haven't got any first hand experience of these models, I just knew the answer because i'm an engine nerd lol. Maybe just boot the throttle here and there if you've been in 2 cylinder mode for an extended period of time, just so you're not putting loads of unburnt oil into your cat at once. If it's enough oil that you can see it, then IMO it will definitely shorten the life span of your cat in the long term.
Edit: If you're new to the car then definietly keep a good check on the oil level. Eco engines and engines with cylinder deactivation often use more oil than more traditional designs. That's the main reason i said i don't think they are much benefit in the real world, as the slighty higher MPG is often offset by the fact they burn more oil.
If continual 4 cylinder is known to cause other issues, then i'd just stick with letting it do what it wants to do. I haven't got any first hand experience of these models, I just knew the answer because i'm an engine nerd lol. Maybe just boot the throttle here and there if you've been in 2 cylinder mode for an extended period of time, just so you're not putting loads of unburnt oil into your cat at once. If it's enough oil that you can see it, then IMO it will definitely shorten the life span of your cat in the long term.
Edit: If you're new to the car then definietly keep a good check on the oil level. Eco engines and engines with cylinder deactivation often use more oil than more traditional designs. That's the main reason i said i don't think they are much benefit in the real world, as the slighty higher MPG is often offset by the fact they burn more oil.
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As you've driven the car for 68,000 miles, is this puff of smoke a new thing or has it always done it?
I noticed it from about 40!000. But could have always been there you have to look at the right time. I wish it was easy to turn the eco mode offā¦.
Obviously there is a natural variation between engines, but our 2018 1.4 EcoTSi has only ever needed minimal top-ups between oil changes.
Interesting thanks spoke to garage they seem to think oil usage isnāt outrageous and can varyā¦
yeah you have to let it sit on 2 cylinders for a couple of mins at least, Accelerate or put a load like a hill you may see something (hopefully you donāt).
Final update on this, the engine gave up in cylinder 3 Totally went. 
many pounds spent a donor engine new clutch etc . Now running like a dreamā¦..
many pounds spent a donor engine new clutch etc . Now running like a dreamā¦..
Glad its sorted but that's crap! - curious; what were the symptoms when it went? did the smoking get worse?Final update on this, the engine gave up in cylinder 3 Totally went.
Thanksā¦ the car started to misfire a little, not a huge amount. Then one drive home misfired big time limped home. Couldnt get coil packs out to investigate welded on. So local garage helped out. When took spark plug out of cylinder 3 it was melted and no compression what so everā¦.
That's terrible. Do you know what failed?Final update on this, the engine gave up in cylinder 3 Totally went.
I'm a bit concerned that there was no compression at all, wondering if the 'ECO' cam actuators had jammed the valves open?
It was a tough choice.. we know the cylinder had no compression after it failed and in the past the plug on 3 on got oily regularly so changed an injector which seemed to cure the wet/contaminated plug. Back then we did a compression test and all cylinders were fine. So knowing there was a bit of history! So the question was did I pay to find out what it was then have to pay repair cost on a 99k engine or swap it for a newer one with on 61k on it whilst changing everything I could while the engine was out. So I decided not look back and just swap it out.
time will tell but so far looking good! Did 4 hour motorway round trip it worked well. But have to admit listening to every noise atm.
Thanks.. I know originally went to Seat many miles back they didnt have any idea. It is unusual as you said mostly only hear good things on the 1.4 150 act.
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