Just brought my first Audi at 20 paid £4400 has 110k miles, drove car home and blueish black smoke coming from rear as I accelerate hard, also have a slight knocking from top of engine which goes if I blip the throttle, was driving along in 6th gear 50mph and epc light come on however stopped car turned it off and on and hasn’t come back since , also keep getting a low oil pressure light however car has sufficient oil. was told by my mechanic all can be fixed by replacing the pcv valve anyone had similar issues, or anything related to this. Thanks George :)

Welcome George,

Did you buy this car from a dealer, or was it a private sale?

Regards,

Gareth.

Hi mate brought it private 5 days ago

Have you got a copy of the advert George, and how long did the owner say he had owned it?

Unfortunately not owner said he had it for about 8 months

17 hours ago, George20s said:

Just brought my first Audi at 20 paid £4400 has 110k miles, drove car home and blueish black smoke coming from rear as I accelerate hard, also have a slight knocking from top of engine which goes if I blip the throttle, was driving along in 6th gear 50mph and epc light come on however stopped car turned it off and on and hasn’t come back since , also keep getting a low oil pressure light however car has sufficient oil. was told by my mechanic all can be fixed by replacing the pcv valve anyone had similar issues, or anything related to this. Thanks George :)

Hi the low pressure problem, the only way to check is to get it scanned and check the oil pressure on live data, if its the oil can in red on the dash then you have a problem as it could need a new oil pump, worse case, or the strainer on the pump will have to be cleaned, but either way its a sump off job, replacing the PCV may well cure your problem with the smoke but I would be inclined to get the injection checked first along with the EGR function as I am not sure which engine you have but all the later models had the PCV built in to the rocker cover which will mean a new cover.

Steve.

Hi mate thanks for the reply oil levels are sufficient in car has only come on twice now when the weather is very hot, I have the 1.8 tfsi

I believe Steve was referring to oil pressure not oil level, hence the possible need for a new oil pump.

Ahhh gotcha no red oil can on dash

Nevertheless the car needs to be scanned on a decent code reader as Steve suggested. Warning lights on the dash are not enough to diagnose faults.

Ok will do that, the thing is it has no check engine light or any lights on the dash it’ll be only when I’m driving they flash up and go after a couple of minutes

3 hours ago, George20s said:

Ok will do that, the thing is it has no check engine light or any lights on the dash it’ll be only when I’m driving they flash up and go after a couple of minutes

Hi any warning light even if appears and disappears warrants investigation as the way the software works on Audis is it monitors faults and severity until they come up a maximum of ten times this then defeats the unlearning counter therefore it becomes a permanent code and possibly limp mode, now that you have announced its petrol I would definitely check the injectors but I do suspect if it smokes when accelerating hard it may be worn piston rings, get a compression test done to rule that out.

Steve.

Ahhh damn that doesn’t fill me with hope as piston rings are an engine tear down, thanks mate appreciate it will get compression tested and pray

Didn't you have the car inspected or assessed by somebody knowledgeable before purchase?

I brought my dad with me and he’s pretty good took it for test drive and it was fine was only when I got home did it start

23 hours ago, George20s said:

Ahhh damn that doesn’t fill me with hope as piston rings are an engine tear down, thanks mate appreciate it will get compression tested and pray

Hi I am not trying to frighten you but am merely pointing out what may cause the problems you have, the only realistic solution is to have the car scanned, the only problem with test driving is normally the tester drives like Miss Daisy so as to not alarm the vendor, when I bought my car at a dealers in Warwick we went for the drive with the dealer and my mate who took me up there I made sure the car was well up to operating temperature and drove round until I found a bit of dual carriageway and then gave it beans in every gear with my mate watching the back for smoke, the dealer was not impressed and asked my friend if I always did this to which he replied Oh yeah he is gonna be using it for a taxi and this has just proved it don't smoke, misfire ,or overheat and knock, all the ones I looked at got the same and if they did not like it I walked away.

Steve.

Yeah see when I brought it the guy was giving it beans and nothing was untoward so that’s why it’s very puzzling, thanks for replying am due to get car scanned in the next couple of days so will give an update then