SoftwareAndSwarfega
Member
Hi
I bought my FSI back in early September and she’s never felt quite right. I just thought I’d post what symptoms she had and what I did to resolve them; it’s nothing that is not mentioned elsewhere but I hope it may of be use to someone else to have them in one place.
So, from day one there was hesitation whilst setting off from a stop (at junctions etc), sometimes to the point where she felt like she was going to stall when the clutch began to bite, and I had to de-clutch and really give some revs to make it across the road at times. The solution was to replace the fuel tank breather valve. (That link is for exact one I purchased). Once fitted (5 min easy job) she felt much much better and the hesitation was pretty much gone - no more risk of death at junctions.
However, she still didn’t feel quite right, and felt flat at times at higher revs - but VCDS (unregistered lite version) showed no codes, apart from intermittent oxygen lambda.
After a few weeks, not a huge amount of miles, the EML came on whilst I was driving back from my dads house and I thought she was losing fuel. What I thought was fuel loss turned out to be a transient glitch with the fuel gauge (it’s been fine since) but the EML light was due to codes 16684 and 16685, being multiple cylinder misfire and a misfire detected on Cylinder 1.
This morning, I set out to diagnose the cause. First, I checked the earth cable (the one behind the passenger headlight). It looked fine but I removed it, cleaned the mating faces anyway and refitted. She hadn’t been started for a couple of weeks, so was very cold and the idle was lumpy. I then checked the connection to the camshaft sensor (right hand side, top of the engine block) and to the naked eye it seemed absolutely fine, so I put it back. I also unscrewed the sensor itself and looked inside the block - nothing untoward - so I refitted. So, on to the cylinder misfires. VCDS said cyl 1 was misfiring so I swapped over the ignition coils of cylinders 1 and 3, cleared the VCDS codes and then started her up and waited for the EML to come on again - which it duly did after some gentle revving. She was still idling lumpy and there was some popping at the exhaust but this time VCDS reported a misfire on cylinder 3, instead of 1, which indicated that the coil pack that had been in cyclinder 1 (but was now in cylinder 3) was very likely duff. Three of the coil packs seemed to be the original vag parts and one was a Delphi. Not wanting to replace just one, I duly purchased 4 new Bosch coil packs and also decided to fit new Denso spark plugs at the same time (see photos for specific part numbers). This cost me circa £170 but it was worth it, as once fitted the transformation was amazing. Perfect idle, no hesitation, free revving and feels great. Even my wife said she sounded good when I drove off for a test drive.
So, for the moment (fingers crossed) I have an FSI that is pretty much everything I wanted her to be.
The whole job of replacing all 4 coils and spark plugs took about 20 minutes. It was a bit fiddly getting the actual coil packs out - gentle levering with a wide blade screwdriver - and then those bloody notched VAG cable connectors that you need to gently lever away, but other than that it was easy. Just to be clear, I’m not a car mechanic, just a DIYer.
I hope this write-up is of use to someone.
Nb. I’m keeping the Delphi ignition coil that I removed as a spare, as it looks fairly new!
I bought my FSI back in early September and she’s never felt quite right. I just thought I’d post what symptoms she had and what I did to resolve them; it’s nothing that is not mentioned elsewhere but I hope it may of be use to someone else to have them in one place.
So, from day one there was hesitation whilst setting off from a stop (at junctions etc), sometimes to the point where she felt like she was going to stall when the clutch began to bite, and I had to de-clutch and really give some revs to make it across the road at times. The solution was to replace the fuel tank breather valve. (That link is for exact one I purchased). Once fitted (5 min easy job) she felt much much better and the hesitation was pretty much gone - no more risk of death at junctions.
However, she still didn’t feel quite right, and felt flat at times at higher revs - but VCDS (unregistered lite version) showed no codes, apart from intermittent oxygen lambda.
After a few weeks, not a huge amount of miles, the EML came on whilst I was driving back from my dads house and I thought she was losing fuel. What I thought was fuel loss turned out to be a transient glitch with the fuel gauge (it’s been fine since) but the EML light was due to codes 16684 and 16685, being multiple cylinder misfire and a misfire detected on Cylinder 1.
This morning, I set out to diagnose the cause. First, I checked the earth cable (the one behind the passenger headlight). It looked fine but I removed it, cleaned the mating faces anyway and refitted. She hadn’t been started for a couple of weeks, so was very cold and the idle was lumpy. I then checked the connection to the camshaft sensor (right hand side, top of the engine block) and to the naked eye it seemed absolutely fine, so I put it back. I also unscrewed the sensor itself and looked inside the block - nothing untoward - so I refitted. So, on to the cylinder misfires. VCDS said cyl 1 was misfiring so I swapped over the ignition coils of cylinders 1 and 3, cleared the VCDS codes and then started her up and waited for the EML to come on again - which it duly did after some gentle revving. She was still idling lumpy and there was some popping at the exhaust but this time VCDS reported a misfire on cylinder 3, instead of 1, which indicated that the coil pack that had been in cyclinder 1 (but was now in cylinder 3) was very likely duff. Three of the coil packs seemed to be the original vag parts and one was a Delphi. Not wanting to replace just one, I duly purchased 4 new Bosch coil packs and also decided to fit new Denso spark plugs at the same time (see photos for specific part numbers). This cost me circa £170 but it was worth it, as once fitted the transformation was amazing. Perfect idle, no hesitation, free revving and feels great. Even my wife said she sounded good when I drove off for a test drive.
So, for the moment (fingers crossed) I have an FSI that is pretty much everything I wanted her to be.
The whole job of replacing all 4 coils and spark plugs took about 20 minutes. It was a bit fiddly getting the actual coil packs out - gentle levering with a wide blade screwdriver - and then those bloody notched VAG cable connectors that you need to gently lever away, but other than that it was easy. Just to be clear, I’m not a car mechanic, just a DIYer.
I hope this write-up is of use to someone.
Nb. I’m keeping the Delphi ignition coil that I removed as a spare, as it looks fairly new!
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