Hi all! Newbie here!! 1.6Fsi running problems

First off, a big hello to you all!, been browsing the site for months but this is my first post so here goes.

Just bought my second A2 a 1.6 Fsi & over the past two weeks have started to notice flat spots/hesitation in the acceleration curve & it's getting worse. Happens throughout the gear range. You put your foot gently on the accelerator & she pulls away smoothly then seems to plateau before regaining acceleration.

Now I should explain, I've plenty of experience of car ownership & diagnostic headaches but whatever is causing this I've only got the money to sort IT out, not umpteen attempts by process of elimination.

From reading others posts it sounds as if this could be the famous throttle body problem, failing that, injectors or fuel pump.

She still runs fine & once you reach the speed you want she seems to hold it fine. No dash warning lights + plus DIS confirms 'OK' as usual.

Any guesses?

Cheers, Paul.

Hello and welcome

I'll be the first to say, and this is something I learned quickly...
There isn't really any point in guessing. You need get any diagnostic codes read. That will narrow down the cause considerably.

Flat spots can be caused by lots of things from knock sensors to fuel problems.

I'm pretty sure others, the experts, will be along to assist soon.

Chris

Not an expert on the 1.6 but will gladly scan the car for you if needed to add any more detail to your issues which will help hugely with the more informed to guide. Based in Trowbridge so quite close and can help (at no cost!) to scan and post results on here for you.

PaulA2 said:

Not an expert on the 1.6 but will gladly scan the car for you if needed to add any more detail to your issues which will help hugely with the more informed to guide. Based in Trowbridge so quite close and can help (at no cost!) to scan and post results on here for you.

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Hi Paul, thanks very much!! Thats very kind of you. Sounds like an obvious first port of call, only asked everyone cos no warning lights are on. When are you available and what's the proceedure for contacting you? PM's??

The usual suspects on the FSI are :
injectors
coil packs
intake manifold (complicated item !)
fuel pump
various sensors (fuel pressure, air meter, lambda 1 and 2, etc...)

GF03Fsi said:

Now I should explain, I've plenty of experience of car ownership & diagnostic headaches but whatever is causing this I've only got the money to sort IT out, not umpteen attempts by process of elimination.

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Hi Paul,

First off, Welcome to the A2OC.

Ensure you only use good quality fuel like Shell V Power or BP Ultimate, the FSi really does need good fuel for it to run well.

A scan is really the first port of call, however, if you're working on a tight budget to resolve issues with the FSi, then I suspect a 1.4 TDi or petrol variant might have been a wiser move.
These issues are hard to find on an FSi if owned for many years and full history is known, but a newly purchased FSi where you don't know it's history with regard to servicing, fuel type, treatment, etc is, I suspect, going to be a hard one to resolve on a first attempt.

If you have any service history, with receipts, it's worth checking that plugs, coil packs, all filters and any sensor replacements have been genuine OE.

Good luck in getting it sorted quickly and at minimal cost.

Cheers

Jeff

Update on this issue:

Did a full scan of the car for Paul and the following code was stored:

Address 01: Engine Labels: Redir Fail!
Part No: 036 906 013 F
Component: MED7.5.11 4628
Coding: 00051
Shop #: WSC 00487
VCID: 122053EE5EA31A8E3D3-513C
WAUZZZ8Z73N025325 AUZ7Z0B2265541
1 Fault Found:
17700 - Map Controlled Engine Cooling Thermostat (F265)
P1292 - 35-10 - Open Circuit - Intermittent

I have deleted this now and will scan again in a week or so to see if it has come back.

It was also noted his scuttle trim was loose so I whipped wipers off and fitted it correctly in the windscreen channel in case water was running under. Engine seemed dry though.

A second issue is that when running the interior light fluctuates as do the headlights. Voltage fluctuates about 0.5 volts up and down when engine runs but holds steady when engine off. The battery is a non genuine item and seems small to me but can't comment on 1.6FSI batteries. Initial thoughts are alternator on its last legs, or possibly worth cleaning earth up and I believe the voltage fluctuations could impact on the running of engine but look to the community for guidance as know nothing about the 1.6FSI.

Hi the error code is referring to the thermostat and in my experience this is a common problem. When my first one died i had to have a whole new unit(not a small assembly-on the right hand side of the engine at the back) but the second time it was just the sensor/heater that needed to be changed. But as you stated lets see if it comes back--the voltage fluctuation could be an earthing issue that will also cause rough running. The fsi is very sensitive to slight changes so this is worth checking out first. cheers and good luck mike

second issue sounds similar to my new post, I believe the dip in headlights whilst turning steering (stationary) is common, and have just checked interior light which also dims whilst using power steering (stationary again).

were the fluctuations (I referred to it as flicker in my post) visible whilst driving?

Hi everyone & thanks for all the advice so far.

Just to update from the scan yesterday, the warning light status has changed.

The EML came on for first time this evening & is staying on despite the car being restarted. Doesn't add anything to situation just thought I'd keep you up to date. Car still driving very rough.

Thanks. Paul

Paul, will hope to meet up Thursday evening to scan again so we can move this forward as per telcon last night.

Scanned again to show the following code:

17700 - Map Controlled Engine Cooling thermostat (F265)

Clearly there is an issue with the thermostat setup but as I have no experience on the FSI and to hopefully avoid Paul spending cash unnecessarily we were hoping some more in the know of these cars could perhaps suggest options.

I guess the platinum solution is to get a complete housing and sensor but is there a way to test if just a sensor or other options may assist first?

Sorry to add to other possibilities but I have had a whole new lower manifold assy and changed the EGR valve. Spent hundreds and mine still does it. Diagnostic now says it is a sensor in the bottom of the exhaust manifold but I cannot afford to spend any more on it.
Beginning to wish I had bought the low mileage 1.4 I saw that had several damaged body panels. It may not have looked good but it would have driven fine! oh well c'est la vie.

Alan Morriss said:

Sorry to add to other possibilities but I have had a whole new lower manifold assy and changed the EGR valve. Spent hundreds and mine still does it. Diagnostic now says it is a sensor in the bottom of the exhaust manifold but I cannot afford to spend any more on it.
Beginning to wish I had bought the low mileage 1.4 I saw that had several damaged body panels. It may not have looked good but it would have driven fine! oh well c'est la vie.

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I would hope that you had error codes for all these problems rather than just change these expensive items just on a whim ? It would seem the original poster of this thread is now armed with the evidence that the thermostat is causing the EML. I'm not sure there is much of a pets cost saving in just doing the sensor so I would recommend the whole unit be changed.
Unfortunately the FSI is a complicated engine that can be expensive once some of these errors start to appear. But once sorted I think it's great. Cheers mike

Cheers mike, I have directed that Paul liaises with fellow 1.6 FSI owners like your good self who have long term ownership knowledge. I suspect he will swap the complete setup, is it a big job? If it's just a bolt on off replacement then I am happy to assist but if it needs calibrating etc then will leave to the specialists.

Paul, just to say a big thanks for your input, much appreciated.

Hi, yes I did have errors but each time I had the offending item sorted another popped up. I am hoping this sensor is the last one because you are right. It is grat when it is running properly.

Sorry for slow reply as I'm on holibobs. Yes the thermostat unit is just bolt on with no vag com cvds involvement. It's an awkward job due to location but made easier if you tip the engine forward slightly. There is a plastic pipe that links the water pump with the thermostat housing this pipe can split so whilst you have it all off it may be best to replace at the same time.
Good luck mike