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Mine had a bit of miss ... at a bout 4,000rpm this morning. Now it was cold, 30 seconds from home and the miss was enough to cause the engine light to flash, I pulled over and shut it down for a moment and it started up fine, no lights, no warning and has driven perfectly for the rest of the day.
When I got home I figured I would run VCDS across it to see what's what. Not what I wanted to see, but it is still on the stock plugs and is due a service so it will get looked at as soon as I remember to book it in. The miss is a one off, so hopefully just a random miss down to something else.... hopefully.
Mine had a bit of miss ... at a bout 4,000rpm this morning. Now it was cold, 30 seconds from home and the miss was enough to cause the engine light to flash,
...
...and it seems mine N249 has a few issues too
I deliberately let mine warm up for a good few minutes in the mornings. It takes 30-40 seconds for the revs to settle while it runs like dogsh$t. Was it that soon after startup or had it settled? There's no way i'd be getting it up to 4000 or more straight away. I've heard it's also wise to let the supercharger oil (sealed permanently) warm up before you give it some curry.
Did you already do your coil packs? If not maybe do them at the same time as the spark plugs. When you pull your plugs take the opportunity to have a look at each one and note the colour (ie white = lean burning cylinder). Curious to see if there's variation across the cylinders.
If you replace the n249 might as well do the n75 as well. My mechanic did my n75 and told me his supplier at VW said to do both and i laughed it off as an up sell. Sure enough, my n249 shat itself shortly after. If you replace those make sure you get the latest versions as they were updated. As mentioned previously, I noticed a solid recovery in performance after i changed those valves, although mine were so far gone i was losing boost at higher altitude (like 1,000m).
The run like dogsh$t on a cold start is when it's doing it's double fueling and overlapping valves in order to heat up the catalyst faster.
It only does this if the engine/coolant temperature is between 20 and 30 Celsius when you start, outside this range it does not do it.
I advise interrupting this process, soon as you feel/hear it doing it, turn off the ignition and wait a few seconds and restart. It won't do it on the 2nd start.
I don't like it doing this as it results in some bore wash - which is not a good idea on this engine. It's purely an emissions thing (although oddly doesn't do it at less than 20c engine temps).
Thanks Blower, that's the first time i've had a real answer about that.
It sounds rough as guts when it starts and I normally let it settle while i deal with the garage door and the playlist etc.
Is it a function that's written into code that could be altered or possibly turned off? I live in Sydney near the coast so it's often in that temp range.
I don't know if it can be programmed out via an ECU tuner, I doubt it as will need custom coding which is beyond the usual mapper. I wish it could as I find it annoying and as you say when it does it, it runs rough as hell with the exhaust burbling and sounding pretty rough.
I did a lot of monitoring with VCDS to see what it was doing, and that's how I found out it only did it between those engine temperature ranges - it did seem to be ambient but it wasn't tracking that consistently, on a cold start your engine will be close to ambient. I found it sometimes did it during the day if I left the car for a while after a run - realised then it was engine coolant temperature it was tracking as after leaving the car for a while the engine temp would drop back into this range.
My current solution is just turn the engine off when it does it and start it back up. It won't do it again if it has recently done it. I am however designing a circuit to read the current coolant temp and if it is in that range, then feed a false signal to the ECU (just outside the (20-30c range) when starting and then feed it the real engine temp shortly after....it only needs to give the false reading for the moment the engine starts.
I have seen every 1.4 TSI from 2009 to 2012 do this, that includes the 90KW CAXA, 118KW CAVD, CAVE and CTHE engines.
I have seen every 1.4 TSI from 2009 to 2012 do this, that includes the 90KW CAXA, 118KW CAVD, CAVE and CTHE engines.
Yeah, well i initially thought it was my dud 2009 engine but the 2011 engine did the same thing. It doesn't always sound like a cough or a missfire but the boost gauge always reads 0 PSI while it does its thing, then settles back to ~-20 mmhg once it has its ***** together.
Yep no vacuum sounds about right - overlapping valves letting some of the exhaust gasses back in on the intake stroke to try heat up the block....not going to get much of a vacuum when half your intake stroke is exhaust!
I deliberately let mine warm up for a good few minutes in the mornings. It takes 30-40 seconds for the revs to settle while it runs like dogsh$t. Was it that soon after startup or had it settled? There's no way i'd be getting it up to 4000 or more straight away. I've heard it's also wise to let the supercharger oil (sealed permanently) warm up before you give it some curry.
Did you already do your coil packs? If not maybe do them at the same time as the spark plugs. When you pull your plugs take the opportunity to have a look at each one and note the colour (ie white = lean burning cylinder). Curious to see if there's variation across the cylinders.
If you replace the n249 might as well do the n75 as well. My mechanic did my n75 and told me his supplier at VW said to do both and i laughed it off as an up sell. Sure enough, my n249 shat itself shortly after. If you replace those make sure you get the latest versions as they were updated. As mentioned previously, I noticed a solid recovery in performance after i changed those valves, although mine were so far gone i was losing boost at higher altitude (like 1,000m).
Around how much are these valves (n249 & n75) from VW Parts?
MY18 VW Passat Alltrack Wolfsburg Edition + Panoramic Sunroof + some extra goodies... (Pure White) MY17 ŠKODA Superb 206TSI 4x4 + Sunroof + Tech Pack + Comfort Pack + some extra goodies... (Moon White)
I had the same splutter again yesterday, although I haven't had a chance to run the scanner over it I assume it will say the same thing. Same deal, cold engine, pulling out in busy traffic round the corner from home and hit 4,000rpm in second left me with a splutter and a flashing engine light. Everything still running smoothly otherwise, even with the light flashing. Pulling over and turning it off and on again clears the light and everything works as expected.
I wonder if a DSG equipped car would hit these revs more often vs a manual as the DSG tends to use more of the rev range (in my experience anyway).
In any case, it's due it's first major service (with 27k on the clock ) and is booked in for Wednesday so we will see what happens then.
If it has an engine or heartbeat it's going to cost you.
That's weird because my brother has a 2009 model and it does exactly what you are all explaining. It sounds terrible on start up and about 30 seconds later it's all good. I have a 2012 model and mine never ever does that. I hear the supercharger warming up with a distinct siren like sounds and after 30 seconds that stops. I assume this is something they stopped doing as the engine grew older.
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