New car to me but acting strange... possibly?

[jmejamie]

So I've only recently had the car maybe a month or so. Find the power to be nice when it's in full swing but sometimes I feel like its quicker than other times. Full on booting it doesn't always seem as quick as light throttle and the boost kick from that.

Audi A4 B7 S-Line 2.0 TDI 140BHP BRE - NO DPF

Had it remapped which made it even more noticeable between the two situations above.

Since I had it when I first turn it on in the morning it seems to take a second to decide where it wants to idle. The engine also rocks a little finding its happy place but that's only ever first first thing. If I drove it then left it for hours and go back in it wouldn't do it. It doesn't struggle to start though just struggles to settle out. Hot or cold weather irrelevant it seems.

Another thing is when sitting idle you can feel a light engine twitching if you like every couple seconds. Like it twitches then you feel nothing then twitches again... and this is consistent from cold to fully warmed up.

Also sometimes when I'm driving I just find the engine isn't very smooth from 1000 rpm to 1800. Like sometimes lurchy or hesitant but at 2000 rpm its feels alright tbh...

Took some random readings for anyone who might know a thing or two. I sat with it idle and then also held it around 1500rpm or so.

Any advice would be much appreciated!

[ATTACH]Log file[/ATTACH]

Best regards
Jamie

[carbonman]

I had a few oddities on mine when I first bought it - the biggest thing which seemed to help my strange lumpy / running odities was changing the fuel filter - really simple job and for me mad a difference in smoothness.
I also had a lot of comments around the MAF - I did change mine but am not sure if it helped or not - but if you disconnect the wire to the MAF and it runs ok then thats a good sign that something isnt right there.. easy test.

I'm fairly new to the 2.0 Tdi engine, and I guess mine slightly newer as I have the 170 with DPF - I imagine the rest of it is pretty similar...

Cheers :-)

[jmejamie]

Hey!

Thanks for replying! When I first got the car it had a tragic diesel leak... it was literally flowing out the return T piece. After 3 attempts of changing filters, O-rings and then T piece itself I finally sorted that! Then the Tandem pump gasket decided to leak so a new gasket was done on that! So finally I think the fuel situation is under control!

So I've already done the filter and obviously, I'm still experiencing the above issues.

Yesterday I saw your reply and pulled over and just yanked the MAF plug off. I didn't think it drove any differently having unplugged it then I realised that actually the engine was much smoother in the lower RPM and still had the same power higher up... based on this I've ordered my Bosche MAF from eurocarparts and will be going and getting it in a minute.

Just wanted to get this message in as a base before then getting the new unit and reporting my experience! Going to make sure to take VCDS with me to reset any codes once I've put the new MAF in just in case it needs to be done... rather play it safe!

Will report back soon! Thanks for the advise so far.

[jmejamie]

OK, so I've changed the MAF unit. I will be honest and say that the new one feels like its given the car a bit more of a power kick, smoothing out the power that is there. However, i still feel as if the car is actually smoother in the lower RPM with it disconnected...

Whilst on idle the engine is still doing the light twitching which I don't like because I have no idea what that could be?

I also find that around 1000-1300 RPM the engine moves about a fair bit, like it lurches a little and throws the car about if I try to hold it in that range. I've just had the SNUB mount changed and the gearbox amount. I've been assured the other mounts look fine and that the electronic one isn't throwing up any codes... Tempted to unplug the electric mount but I don't know if the mount would be in its firm position or stuck in the softer vibration dampening state?

Any ideas would be appreciated, I don't want to keep annoying my mechanic taking it in there for what seems like little stupid things but as someone who drives a lot I notice these issues.

Thanks,
Jamie