For about the last nine months I’ve been putting up with a less than wonderful car. There was an engine problem in which the car was fine under normal driving until it was floored or even asked to accelerate moderately fast. The symptoms were that the acceleration was hesitant with loss of power and then it comes back on tap in stops and starts.
At first I assumed it was a fuel starvation issue, but running injector cleaner through the system and several full tanks of Optimax didn’t have any effect. Then I suspected a turbo/airflow related issue and a vacuum leak.
I replaced the main turbo hose and the two intercooler pipes with Samco silicon hoses and put in a Forge DV. This seemed to make it better, but the fault was still there. Not long after one of the speed sensors went on the front nearside front wheel so it went into Audi Macclesfield to get that fixed (ABS and ESP warning lights had come on).
The dealer spent two hours looking into engine problem for which i wasn’t charged, but they couldn’t see anything obvious. A diagnostics check revealed it was pulling more air in than normal so they suspected that it is a vacuum-related problem. The turbo tested fine, no other errors came up on the VAGCom or what ever else it is they use to check such things.
The head technician suggested that it could be a brake servo vacuum leak. He said this is a common fault in S3s. It certainly wasn’t something I have come across on the web and neither had any of the guys over at RS246.
The technician also noted that the brake pedal felt ‘spongier’ than it should. Apparently the brake system works off the same vacuum system as the engine and the proposed solution was that the car went back into the dealer for further tests at the diagnostic labour rate Â£85 per hour. They will need to get the car up on the ramp drop the engine out and test it fully. If the brake servo was found to be the fault replacement, a replacement is Â£300 for the part plus the associated labour. Probably looking at Â£1000 all in.
I wasn’t too impressed with this verdict and decided to try some of the suggestions that were made by other owners’ First up was a new Mass Airflow Sensor, which made absolutely no difference. Not long afterwards the car was up for it’s MOT and was whisked into the Car Care Centre in Padfield.
I asked for them to investigate the engine fault too. This is a great Independent firm that I have used before with previous cars.
They hooked up to a diagnositics computer that read the ECU memory and this identified a misfire as being logged. Audi were out of coilpacks, so he put in a new set of plugs and it completely transformed the engine. Closer inspection reveals that the plugs have probably not be changed from new. That’s 65K on a set and they were looking very worn.
Really miffed about:
a) Audi claiming to have run a diagnositics test and having missed this simple thing.
b) The car having done 65K and never having had the plugs changed (from what I’ve read this should have been done at 20K and 40K, but probably wasn’t because they’re difficult to get at).
c) The fact that the service also revealed that the rear disc pads were changed, but the discs weren’t – but needed to be – when it was last done. That’d explain the shoddy braking as they are very ‘lipped’ on the inside surface.