Rickym1221

UPDATE: doing some measuring in VCDS as I got a code saying low fuel rail pressure. It was reading 1.6bar with just ignition on. Start the car it was at 6 bar! replaced both HPFP and cleared codes and the car fired right up, no misfire, pulls as it should!! ps: car smoked from bank 2 exhaust quite abit for about 5 mins then cleared

Hi Gareth, what is it your after, a like or thank you on the replies you give to me? I come back to the site and acknowledge your replies and are obviously grateful. I’ve clearly not "taken the advice and ran" yes… researching other sites that contain information that may not be on this site… that isn’t a bad thing, I’m looking at all possible reasons as to why I’m having these issues but are acting on one at a time.

Not the best pictures… here’s a photo of the borescope. 1 picture is a piston from bank 1, the other a piston from bank 2. Clearly a lot of carbon build up. The carbon is dry on the pistons not wet. There was mass carbon build up everywhere after removing the intake manifold, not just on the pistons. From what I can see the cylinder walls look clean injectors are here however so will install them anyway

Hi Cliff, thanks for the message. Right ok I’ll have to get it looked at. I was going by many other forums etc I’ve looked at where it states higher compression is caused by carbon build in the cylinders (which I’ve confirmed bank 2 has using a bore scope).

Sorry I will have a read now, I’m from the Midlands, UK. will post results later today of compression test

Oh wow looks like I did the test completely wrong! I didn’t remove all plugs I only removed the one I was testing at the time… I didn’t hold the accelerator to the floor. I will certainly redo the test

so it turns out I think I did the test wrong. Car was cold, not operating temp as stated on sites that it should be 🤣 apparently you should see around 25+ psi when engine is up to temperature. This true? If so I’ll redo the test with the car at normal operating temp

Hi magnet thanks for the response! so from what I’ve read 150+ is good compression? Bank 1 that has no issues is the side that’s giving 150+ bank 2 is showing 200+ I’ve not long had the car, what I have found is the misfires are random across bank 2. I’m also getting codes for: p1575: right engine mount P0660: Intake manifold tuning valve bank 1 i have brand new injectors arriving tomorrow so will be installing them. thanks ps. From what I’ve researched high compression is caused by high carbon build up. I’ve used a bore scope to look at the pistons on bank 2 compared too bank 1 and bank 2 pistons are covered in carbon

Hello, reaching out to all who can help on this! Let me explain. S5 4.2 V8 (B8). Car has a misfire on cylinders 5-8. Car idles rough etc. I have tried many things like spark plus, coil packs, carbon cleaned the valves and intake, swapped sensors from bank 1 to check for faults but nothing. so… did a compression test and on bank 1 I’m getting all 150-160psi and bank 2 I’m getting 210-225psi. stuck a scope down to see what the pistons are like and wow… covered in carbon! What would be the cause of this? any advice I appreciate