TSI Turbo Behaviour

[cdd101]

Hi All,

I have recently bought a 57 plate 1.8 TSI L&K with around 30k on the clock, and am so far very pleased with it. A big step up from my old diesel Ford Focus which didn't always start!

I have one question though, and I'm not sure if this is normal behaviour, the beginnings of a fault, or just my driving style whilst getting used to a petrol car again.

I've noticed, and it only seems to be when the engine's cold, when trying to pull away slowly/steadily (ie not flooring it after the traffic light turns green!), that the turbo seems to kick in briefly, then drop out, then kick back in again, over a period of about a couple of seconds, giving the the drive quite a 'lumpy' feel. This is mostly predominant in 2nd gear, but also in 3rd. If I drive it a bit harder I don't notice it. It would be between 15 and 20k rev wise. Once the engine's warmed up I don't notice it but I don't know if this is just because I've got accustomed to the feel of the car over a journey and whether it is just uneven pressure from my right foot on the accelerator, or whether there is a fault developing with the turbo which would cause such behaviour? Or is this just how the turbo on this engine behaves when cold?

Any thoughts would be welcome!

Cheers,

Chris

[SBirch]

I've noticed, and it only seems to be when the engine's cold, when trying to pull away slowly/steadily (ie not flooring it after the traffic light turns green!), that the turbo seems to kick in briefly, then drop out, then kick back in again, over a period of about a couple of seconds, giving the the drive quite a 'lumpy' feel. This is mostly predominant in 2nd gear, but also in 3rd. If I drive it a bit harder I don't notice it. It would be between 15 and 20k rev wise. Once the engine's warmed up I don't notice it but I don't know if this is just because I've got accustomed to the feel of the car over a journey and whether it is just uneven pressure from my right foot on the accelerator, or whether there is a fault developing with the turbo which would cause such behaviour? Or is this just how the turbo on this engine behaves when cold?

Yes I have this, asked the dealer to check it when it had it's first service this week. However no error code and they couldn't reproduce it. On my version it's intermittent and is more likely to occur in higher gears when only using light throttle. Several others on here have also raised this issue. So probably a "feature".

Simon

[brad1.8T]

Yep, mine kind -of does this. Just a fraction jerky in first when taking off from the lights under light throttle. Stopped doing it when i Bluefinned it. I put it down to some turbo shenanigans like dumping boost to maintain the flat torque curve.

[cdd101]

Thanks for the replies, interesting to hear others have noticed similar behaviour. I thought I'd read of someone else mentioning this in a post when I first joined but I can't for the life of me find the thread!

I'll mention it to the garage when it next goes in and see if they find anything.

If anyone has any experience of garages acknowledging the issue I'd be interested to hear what the outcome/cause was.

If it is a 'feature' then it's a little disappointing as it can be quite noticeable in 1st, 2nd and 3rd. I've ruled out my driving style as I've had the car a while now and I experience the drop and surge in power when I'm deliberately being very conscious of my driving technique.

Cheers,

Chris

[SBirch]

I have never noticed this in 1st or 2nd gear or 6th, but it might be just be that I tend to shift up early in the lower gears and low rev's in high gears tend to give a sluggish response anyway.

I didn't manage to test drive 1.8TSI before placing my order so was basing it's performance off the 1.4 TSI I did test drive and a 1.8T Golf GTI I had for a few years. To be honest I think the 1.8T was in some ways a better engine, it certainly reved freeer and produced less noise under load. Torque and ecconomy is certainly better in the TSI though. Town driving gave about 26 MPG and I can do 30 odd MPG in the TSI and high 30's / low 40's on a run.

Simon