1.6 throttle body

[Dubturbo]

My 00 A3 1.6 (AKL) suffers from what seems to be the classic TB woes - poor idle, bad power loss and jerky acceleration through the revband. Cleaning and resetting the TB didn't solve the problem, although it is intermittent - sometimes it runs perfectly, and others very badly indeed. Next I'll be looking at replacing the TB, but I don't want to put the exact same part in if I can avoid it, as it'll only end up happening again! Does anyone know if there have been any revisions of the TB for this engine, or if TBs from other engines (the AHL 1.6 engine used in the A4 for example, which seems a lot more reliable) can be used instead?

Thanks!

 

[dan_a3]

Does there seem to be a pattern of the times that it runs rough? Have you plugged it into a computer?

 

[Dubturbo]

Hey, thanks for the reply

Insofar as I can tell there's no particular pattern. Sometimes it's when the engine's cold, sometimes when it's hot, and with varying levels of severity when it does happen. I did hook it up to VAG-COM to check for codes, and nothing on the engine side of things seemed amiss at all, and no temp senders were out or anything like that. I cleaned out the TB and reset it afterwards, which did make it run a little better in general, but when things go funny it's still as bad as it was.

 

[Tastyterrier]

Have you tried cleaning/changing the MAF sensor? As a quick check, try taking out the sensor, spray some contact cleaner inside, stick it in the airing cupboard to dry off and refit it.

 

[Clach]

Sorry for butting in, but is it easy to change the sensor?

 

[dan_a3]

Ive got an AKL 98 A3 and sounds like ive got a similar problem to you. I could go out on a freezing cold morning and it will start up perfect and run lovely. Could stop at a mates for 10mins and go to start it, and it just turns over and turns over just will not start. You have to pump the gas a few times to get it to start and then it will fire-up, but runs like a dog, sounds like on only 3 cylinders. Turn ignition off then on again and its perfect again. If i dont turn off igntion and restart it, it will missfire and hesitate all the way up the road throughout all revs, yet when you restart it, it runs like a brand new car! Ive changed temp sensor, cleaned MAF and throttle body and had it plugged into various daignostics and it does not pick up anything. Im quite sure its something electrical, it must be to be that intermitent. I could have no problems for 3 weeks, stop at the pub for half hour and be stuck there!

 

[Dubturbo]

Yes that sounds painfully familiar! You've ruled out so many of the obvious suspects that it has to be something funny like that. Would have thought MAF like Tastyterrier said when the TB and temp sender were ok. Although an electrical problem should throw a code, shouldn't it? It's a pity, because it spoils an otherwise lovely car

It seems to be a fairly common problem though from what I can see....surely someone somewhere has a definitive solution?

 

[Sam-K]

snap snap snap.

Mine sounds rough if i haven't used it for a couple of days.. its sounds burbly through the exhaust.. but is fine when it gets warm again..

 

[rodenal]

Hahahaha so the cold weather is doing this to everybody's poor wee 1.6???

My car's running like a dog every cold morning just now, running on 3 cylinders until its warm, when it'll run better but not perfect!

Splutters and coughs into life too.

I suspect coilpack(although mine has the good ones) or perhaps an injector problem(worryingly)

And to top it all i've lost my Vag com cable, so does anybody in or near glasgow have one that i could use to read my codes over the weekend sometime??

Btw for what its worth - if your car is running really rough i would say its unlikely to be the Maf - that's more likely to cause hunting at idle and a bit like it's hitting a wall when using the throttle, not a misfire as such.

Throttle body also quite unlikely as again this will cause it to run a little bit jerkily, but it certainly wont give you that scooby type sound.

I also need a (suspected) new thermostat, but i dont really think that would cause the problems i'm experiencing with the car just now

 

[dan_a3]

Hmmm see its not just when its cold with mine, i could start it up on a freezing cold morning covered in ice when its been sat there and not moved for 4 days and it would run fine. Its just so intermitent there is no pattern for it. Would of though it would through up a code yeah but it hasnt. Someone has suggested crank sensor.

 

[rodenal]

Mine was the same until very recently, it was totally random but the last few days it's almost constant until its totally heated up.

My car didnt throw up any codes before either, and i've never seen an engine management light come on(i dont think the 1.6 even has one tbh!) I just wanna check it before i start replacing bits n bobs blindly, just incase.

I'm almost certain it's coilpack/spark/injector related - possibly even something to do with moisture

 

[dan_a3]

Yeh thats exactly what i dont want to start doing, just putting bits and bobs on and hoping for the best. The other day i started it up, and as before it just turned over until eventually it kicks in running on 3 cyl. I noticed in my rear view mirror it was really smoking out the exhaust, and as i looked forward there was smoke coming from under the bonnet. I opened the bonnet and it was coming from the bulkhead on the drivers side near to where the brake master is but below it. If i revved the engine via the throttle cable the smoke would increase. After i restarted the engine it was as if nothing had happened it was fine! Might just sell it i think, it ****** me off the things got a mind of its own!

 

[deanmorris1986]

i have a 2001 1.6 and it doesnt seem to like the cold either! when its cold its as if it doesnt want to go and the revs are really hesitant - kind of like the rev counter is being pushed back down? it drops lower than idle too but doesnt cut out.
when i go to pull away its as if im letting the clutch out too quickly and really needs a few more rpm than normal to get going. once its warm it drives fine.
also sounds pretty ropey to me but when i asked a mate to have a listen he seems to think it sounds ok...is it just the way they sound??

 

[dan_a3]

Yours sounds like a temp sensor. You can pick one up for £15 and takes 30sec to fit. That would explain your cold running problems. But with mine it doesnt start at all sometimes!

 

[Dubturbo]

What do you think caused the smoke under the bonnet Dan, an oil leak perhaps and it was the oil burning off? Mine definitely used to have a leak, there's a healthy layer of cruddy oil around the back of the engine!

 

[dan_a3]

Well i thought about that, but it has never done it before and never done it since! I really havent got a clue! Its got to be something related to it not starting.

 

[rodenal]

Were you turning the starter motor for long periods of time?? Could have caused it to burn a bit

 

[jbw]

My old 1.6 a3 suffered from irratic idle and poor starting from day one. It was random - didn't rely on hot or cold weather to perform poorly. I had it in at audi and they told me it suffered from 'a running problem'. Nice.

Eventually I took it to Motorvation in Evesham. They asked to have it in all day to diagnose the issue. When I picked it up they told me air was getting into the fuel mix somewhere. They fixed the piping and reset the ecu. I drove away in what felt like a completely different car and it only cost £50. Admittedly I sold it 2 months later and bought a 1.8T Quattro but during that time it was faultless starting and no irratic idle.

I can dig out the receipt later if you're keen to know exactly what was happening - can't guarantee it's the same for you folk but maybe worth a shot.

 

[Dubturbo]

Interestingly, my starter does stick.....it tends to run for a second or two after the engine starts. Haven't had any smoke from under the bonnet, but if it matches Dan's symptoms we may be seeing a line of common faults to follow up.

Would be great to see that invoice alright JBW, we could have a collection of problems on our hands!

 

[dan_a3]

Well i wasnt turning it over for long really, but the bit i cant understand is that the smoke would increase when i revved the engine. The starter should of been disengaged when the engine eventually started. Someone mentioned about air getting into the fuel and has just got me thinking about vaccum. My brakes are pretty poor, (OK the discs are going to need replacing at the next set of pads, but they are quite bad) and has just got me thinking if a loss of vaccum could be related to the running issues?

 

[jbw]

I couldn't find the receipt last night - moved house recently you see.

I'm not the most mechanically minded of folk but I'm certain the chap told me that air was getting in after the MAF causing the air/fuel mix to be wrong and the engine to struggle.

I'll have another look this evening if I can't find it I can always give them a bell if need be.

 

[Dubturbo]

Hey thanks for looking anyway!

Would certainly make sense if it's an air leak post-MAF. The symptoms do remind me of how an old Golf I had which had a broken seal between the carb and the head used to behave!