Audi A3 engine problem

[micheal balbrig]

Hello A3 1.6 petrol 2002

When temp. reaches approx 95degrees engine light and codes 16685 16688 1668 cyl 1+4 appear (misfire) Codes can sometimes be erased. sometimes I have to wait for engine to cool
The engine light may have gone out but misfiring coninues
I have replaced thermostat and sensor. problem remains
Any ideas on next trial

My thoughts would be ignition coil maybe
Head gasket maybe as i remember seeing signs of mayonaise as cover was removed in the past although not visible now

Thanks

[Crasher]

What is the VIN or engine code, there are two distinctly different 1.6 engines?

[micheal balbrig]

AVU 130452

WAU ZZZ 8L 82A 061462

Thanks Crasher

[Crasher]

The AVU (and closely related) BFQ is a good simple single overhead cam eight valve 102PS unit, light mayo in the oil filler cap is normal, a whole jar full, not. I have had a few with burnt exhaust valves due to guide wear but the engines almost 1980’s Golf 2 simplicity means a top end rebuild is a DIY proposition. The only catch, as with a lot of PQ34 platform parts, is availability, even the oil filler cap breather assembly is now only available genuine from VW Classic in Germany so even a seemingly simple breakage during work can stop you dead for two weeks; however, the breather is well catered for aftermarket. Often these run poorly due to old ignition components and it is not uncommon for us the find plugs 2 and 3 haven’t been changed for decades as without a special plug spanner, they are a bitch to get out and new leads a PITA to feed though. A common reason for your symptoms is the coil pack, it gets very hot and starts to crack; they are widely available but the quality of many is awful. If we were in a hurry we would fit Bosch from Euro or like one we did a few months back, we order in from a company in Europe (NO, not Aut0D0c) and get an NGK 48010 coil, NGK 7044 leads and NGK BKUR6ET-10 plugs. There are quality other suppliers of all three such as Bosch and Beru which are just as good plus many other excellent makes of coil such as Bremi, Delphi, FAE, Febi etc plus HUGO and HERTH+BUSS make nice lead sets. I counted around 140 suppliers of the coil but many are Chinese Replacement Auto Parts.

[micheal balbrig]

Thanks Crasher
I did not change the plugs yet
but i will try the coil first as the problem appears heat related