122 TSI cold start sound

[index]

Greetings!

I've had my Scirocco 122TSI for about a month now. The car is running great, but I am a bit puzzled about how the engine sounds when it's started cold (cold start). The engine
more or less sounds like a diesel for a few seconds before it coughs a little (usually there's a subtle drop, then rise in RPM) and then goes silent. I've talked to my dealer
about it. They claim it's very common for the CAXA engine due to low oil pressure at cold start. However after driving a Polo with the same engine this weekend I'm not
that convinced anymore.

Hoping someone here can share about how their engines run at cold start. Either if it is actually normal or if I should make them take a look at it.

[salsajoe]

The problem I had with my 160 from cold was started OK for a few seconds then sounded as though there was a hole in the exhaust and it ran rough for about 15 seconds before settling down. Sounds similar to your symptoms. The stealers (car still just under warranty) did a bit of research on this and said there is a VW note on this and the repair was to reflash the ECU. No problems since.

[index]

Thanks for your reply. Does and doesn't sound quite similar to my problem as it only for the first few strokes the engine doesn't sound right (I.e not as long as 15 seconds, more like 2-3).
And today, even after standing parked for 10hrs, the engine sounded fine (no diesel sounds). So I'm guessing it's something mechanical as I would think that an ECU (digital) problem would occur every time.

[sperk389]

Hi index, my TSi 160 is at VW as we speak with what i think is the same issue. A little rattly/diesel knocking when first struck up from cold (intermittent) a drop in revs for a brief second then all good. They tell me its a known fault, something to do with an advanced timing valve/module thingy and will take about 2 days to sort as its an engine strip down to get to it. I get mine back next week so i will let you know exactly what they have done and replaced (if anything as its intermittent). Maybe worth talking to your VW specialist in your area about the valve ??

[w8ody]

Hi,

How did you get on with this problem??? I have a month left on my warranty and need to know if this is a serious problem. There seem to be a lot of different views on this, such as the tensioner need replacing.

Index this is exactly how I would describe my problem, the diesel engine noise.

[drfez]

Mine does exactly the same. Horrible spluttering and popping when usually left for around 6 hours - lasts around 30 seconds. Revs around 1200 then drops down to 900 and silent. I've been back and forth to the dealers and after a year I finally got an answer. Apparently the engine does this when the internal engine temp is between 18 and 31 deg or something (hence why only does it if left for around 6 hours, not usually overnight), it diverts the gases and tries to ramp up the temperature quick as possible (no idea why it doesn't do it when temp is lower then?). Apparently all normal. I had loads of work done, ecu reset, camshaft adjuster, tensioner chains, tappets and all this did sweet fa - still got the noise so tempted to say its normal. Hope thats some reassurance that your not alone. There are quite a few threads on this.

[Cuprabob]

I think there are 2 issues being discussed here;

1. The tappety noise that you get while the oil pressure is being built up in the hydraulic tappets.
2. The Secondary Air Injection (SAI) system that under certain conditions pumps air into the exhaust on start up to reduce emissions and get the cats up to operating temp ASAP. While it's running the idle speed is increased.and you get more noise both from the pump and the exhaust.

Although not just at start up, the injectors on these cars also make a distinct "tapping" type noise as does the chain.

[w8ody]

drfez/Cuprabob thanks for the info, you have put my mind at ease!

To be fair my next question was the "tapping" noise but you've answered that as well