help please...turbo or piston rings

[kooch_481]

my car a3 1.8t agu played up again the other day..it was struggling to start on the starter motor and finally kicked into life with puff of smoke..and was stuttering and down on power but seemed ok once the turbo kicked in..after searching through the forums i saw a post about it may be the piston rings which is why its struggling to start..

i had it idling yesterday and gave it a little rev a few minutes after start up and black smoke puffed out of the exhaust

the problem starting is only intermittent which is weird ive changed the fuel filter already

any help wud be appreciated thanks guys

 

[Broken Byzan]

Leaky injectors can cause issues on start up
Head gasket can cause issues on start up with struggling to start.
Turbo seal failure normally smokes on idle but ok on boost and has no bearing on starting.

 

[kooch_481]

thanks for replying..
its really puzzling me cause she starts fine some times others takes ages fires up then dies then fires up again
im hoping its nothing serious
sounds like i may have a couple of problems then with smoke on idle and when revving at standstill..you think the turbo is on its way??
does seem slower then when i first got the car

 

[Andrew@A.L.D]

Take the plugs out and have a look at them as that can tell alot about wahts going on inside

 

[fleeson69]

black smoke is unburnt fuel, could be caused by faulty coil pack which will cause it hard to start, does it misfire under load? eg booting it! also could have a split turbo/ intercooler hoses. check spark plugs as post before, also check that the spark plugs arent cracked! u will no when u turbo goes, loads of blue smoke (oil burning in exhaust) and serious lack of power!

 

[kooch_481]

it only seemed to misfire before the turbo kicked in..it struggled to pull off at low revs stuttered abit then was ok once turbo was in..still stutters abit though

theres no blue smoke as far as i can tell ive only seen black..

stupid question lol to get to the spark plugs i take it ill have to un bolt the coil pack and it will be under there

i havent noticed a change in oil level or anything like that really

thanks for your help guys hoping it is only plugs or coil packs

 

[A3tell]

personally it doesn't sound like the turbo is the problem, if the seals were going, you would see some blue smoke when you let off the throttle. could be something as simple as the plugs, if a coil is playing up she would be missfiring! could be faulty fuel reg or injectors. best thing is to try and find someone with full vag-com and get it plugged in for some readings. good luck.

 

[kooch_481]

im hoping its the plugs or down that route..where can i find someone with vagcom ive got a vag specialist near me so i might take it there to the garage. thanks for your help

 

[fleeson69]

when one of my coil pack started to, it would misfire badly underload, then eventually on normaly driving, to tell if one had gone down, start engine and diconnect each one individualy and see if the engine note changes or starts to misfire, if u disconnect one and engine note doesnt change the coil pack is faulty. it also could be an engine breather or vacuum pipe problem, check pipes for splits. best take kooch advise and put it on vagcom, could be an easy diagnoses! Also lamba sensor?

 

[kooch_481]

thanks ill try the disconnecting thing some time in the week...ive checked all my spark plugs and there all covered in carbon so it may even be that creating a poor spark..hoping its a cheap fix