not feeling the vw quality experience! help.

[schesterg]

Hi everyone. I have a 63 plate 2.0 tsi r line 26000 miles, 1 owner full vw service history. Iv had it since March and was happy with it but slowly iv become disgruntled towards it and I must say not impressed with vw at all. The main issue I'm experiencing is what feels like throttle body issues to me. Gear changes 1-2 and 2-3 are impossible to do smoothly and iv noticed when other people drive tge car it's exactly the same, theres always a lurch or jerk and trying to creep along in traffic in first gear at around 5mph is just dangerous as the car will pull itself along on at idle fine but as soon as you touch the accelerator ever so gently it jerks forward aggressively. Nearly thrown me into the back of another car several times. I am beginning to HATE this stupid Friday afternoon joke of a car which is supposed to be a refined decently built machine from vw. I'm not convinced. It's been to vw and all they seem to do is plug in the ecu, see there are no error codes and say there's nothing wrong with it saying and it test drives fine. Driving at higher speeds seems fine although I have noticed occasional stepped up acceleration in 3rd gear and occasionally the car keeps rolling as if the engine is pulling along without your foot on the gas and then starts to slow after about 5 seconds. Vw deny all this, perhaps jerky uncomfortable riding cars is all they know and are therefore used to it and know nothing else. Others say it's because it has a fly by wire throttle. Any ideas? If I can't get it sorted soon il be selling and turning my back on vws forever. Previously I thought they were the best cars as I had on the road as i had a 2.0 tsi scirocco before in 2009 and it was far better than this one. Can anyone help please.

[schesterg]

And it's a manual gearbox.

[froudeg]

All modern cars are drive by wire, but this doesn't mean they are jerky. If the car has previously been driving fine, but now has become jerky then...

The jerking could be down to misfiring, and as such i would check the sparks and coil packs, particularly if you are on the original sparks from factory.
If you have access to VCDS (vagcom) the best thing to do is log the misfire counter during a drive.

With VCDS you can also do a throttle body alignment, you can also get VW to do that with their equipment.

Is your idle smooth? - ie no jerking or termors felt through the cabin.

[schesterg]

Idle is generally very smooth. When VW had it they said the tick over was too low and the ecu needed an update which they apparently did. They say if thier diagnostic equipment doesn't show a fault there's not much they can do. I think it's pathetic as anyone can plug in a computer, what ever happens to a proper technician/mechanic. It is still under warranty and is booked in again but I fear it will just be the same answer. I don't have vag com how do you get it? Thank for ypur reply.

[froudeg]

Tick over low on these engines...pointing to throttle body or MAF (mass airflow sensor) i'd say.

Ask them to perform a throttle body realignment if they have not done so, and also check the MAF fully - if they know what they are doing they should be able to run some decent tests looking at MAF output on their diagnostics under idle, half and full throttle conditions, to see if the signal sweep is in range of what it should be....but that is what should be done if you really know what you are doing, which is hit and miss with a dealership 'tech'

VCDS (vagcom ) is now called is pretty expensive, £270 http://www.gendan.co.uk/product_VCHU.html
Very handy tool, not just for reading fault codes but for performing all sorts of diagnostics and enabling hidden features or disabling annoying ones.

Thats official version with support available, there are unofficial clone versions out there but i could never condone such a thing

[schesterg]

OK that's great thanks for the advice, I will ask them to do all those things and put in some new plugs. At higher revs and speed it's a fantastic car. Strange thing was yesterday I gave it a good 20 minute blasting down my local a road and gave the engine a good workout once oil was up to 90 degs and today it is running alot smoother and the gear changes seem smoother as well. Who knows. Is this a temperamental engine? Low end revs are very hard to control.

[froudeg]

At higher revs and speed it's a fantastic car. Strange thing was yesterday I gave it a good 20 minute blasting down my local a road and gave the engine a good workout once oil was up to 90 degs and today it is running alot smoother and the gear changes seem smoother as well.

Well that says everything....i was going to suggest you might have the age old problem with all TSI (all direct injection engines for that matter), whereby the intake valves get coked up with carbon buildup, but i didn't as you have such low mileage on the car - i guess if you don't do much motorway mileage daily and its all short trips then you can get the buildup problem with just 26k miles.

A temporary fix, as you have found, is a good blast down the motorway - preferably maintaining 4000+ revs in a low gear, and 70mph+ for 20 minutes continuous. This will burn off a load of carbon and can smooth out your running for a couple of weeks, or even months - but more than likely it will become unsmooth again. The only solution being a full inlet valve clean, which you might be able to get under warranty. If you don't do regular motorway mileage you may need to get this done every 20-30k miles.

To be done properly they need a media blaster (basically a sand blasting machine that uses walnut shells, and a vacuum cleaner), they will have to take the intake manifold off to get at the valves. They will probably be reluctant to do this without evidence, but the fact your short blast down the road has smoothed things out really is a strong indicator of a coked up intake.

There are loads of forum threads about this problem with dozens of people doing their own cleaning - but its not for the faint hearted, you have to be familiar with working on your engine, taking off various ancillary components...and hence you will also need a load of tools.

Still have a look just to see how bad these valves can get!

http://www.golfmk6.com/forums/showthread.php?t=80857
http://www.more-bhp.com/20tfsi_42fsi_rs ... aning.html

Just google 'GTI carbon buildup' for more links.

Btw you will probably find people mentioning 'seafoam', a spray you can inject into the inlet manifold to break up carbon whilst you run the engine.....don't bother as its next to useless in removing these hard carbon deposits. Only manual cleaning with brushes, chemicals, or far better - a media blaster, will clean this up properly.

[Roy_01]

Does this tsi engine has an exhaust gas return valve? I have disabled it on my 2.0 cr tdi, don't want to clog up my intake header.

[froudeg]

The TSI's don't actually have an EGR valve, they use a sort of simulated EGR during startup whereby the valve timings are overlapped to keep some of the exhaust gasses in the cylinder, allowing the engine to heat up faster.
After this though there is no direct exhaust gas recirculation - this is only really needed on diesels to reduce NOX emissions.
Blowby gasses from the crankcase are recirculated via a PCV (Positive Crankcase Ventilation) valve, there is also a basic oil separator to reduce the amount of oil introduced back into the intake from the PCV.

The problem with the carbon build up is purely caused by the direct injection technology, whereby the injectors no longer mix the fuel with the air before the inlet valves, and hence there is no fuel wash over the valves - so no cleaning takes place.
The carbon buildup is mainly caused by oil leaking down the valve stems and burning, leaving carbon deposits on the back head of the valve. Also just the general combustion process in the cylinder will result in gradual build up.
Some of the oil that makes it past the oil separator from the PCV is also burn't onto the valves but this is small in comparison - which is why catch cans have been proven to be next of no use in reducing carbon buildup, at least on these engines.

The only solution is regular motorway (ie medium to high rpm) driving, or scheduled cleaning every 30k miles, or some people have found water & methonal injection to work really well - but were talking some heavy modding here.

[schesterg]

OK thanks guys. I love the car and will work to improve it as it's not always bad and is generally a fantastic car and a real head turner as it's in perfect condition. What does it mean on some days when the exhaust note seems boomy and loud and other days it's quieter and more refined?