Rough idle not fixed with PCV replacement

[simplemanreally]

Not sure where to look from here and it seems the more research I do the more problems it could be. I have a 2011 A5 8 speed 78k miles. The other day I was driving to work, car was warm, accelerated from a stop to about 5500 rpm and got a flashing CEL followed but the EPC and car going into limp mode. Carefully got codes read and made it home about 10 miles and haven’t driven since. Codes read as follows: p2187, p0300, p0302, p0304, p0507.

Initial research led me to the Pcv valves which did have suction at the small tube at the top. I replaced and check old diaphragm, no tears, but now suction is gone at the tube with new all black pcv. Still idles rough and throws epc with every start up. Car isles at a normal 800ish rpm and smooths our a bit about 3k rpm. I am now looking at DV, fuel injectors, carbon build, front or rear main seal leaks (no obvious oil leaks), coil packs or spark plugs. Can’t really afford to keep trying different parts until something works. Please help. This Audi is turning out to be a lemon

[Stazi]

The p2187 and p0507 suggest a massive air leak in the intake path somewhere.


Sent from my iPad using Tapatalk

[Epic-A3]

Try cleaning your MAF. Just a thought. Cheap to try.

Sent from my SM-G950U using Audizine mobile app

[simplemanreally]

Thanks will try this out. I do think the pcv was bad and haven’t checked codes since changing. Will do that today

[simplemanreally]

Bump. Any other ideas? Don’t see any more leaks MAF cleaning didn’t help

[EvolutionArmory]

Rear main seal leak could be it. Especially with P2187 and P0507.

If that seal is leaking air, nothing you replace will fix this until you deal with that.

[simplemanreally]

@evolutionarmory is there a way to tell if the rear main seal is bad without having an oil leak? Haven’t seen a drop on the ground in over 2 weeks

[simplemanreally]

@evolutionarmory is there a way to tell if the rear main seal is bad without having an oil leak? Haven’t seen a drop on the ground in over 2 weeks

[Stazi]

If you check the vacuum in the crank case and it is less than 3-5psi at around 2000rpm then you may have a bad main sail, but I would think it would leak as well


Sent from my iPhone using Tapatalk

[EvolutionArmory]

They don't always leak oil. It might be just enough to let air in though.

Also, does your car have a dipstick? If it does the dipstick tube can be a leak source nobody really checks.

Just throwing ideas out there.

[simplemanreally]

They don't always leak oil. It might be just enough to let air in though.

Also, does your car have a dipstick? If it does the dipstick tube can be a leak source nobody really checks.

Just throwing ideas out there.

It does a dipstick tube that I ordered a dipstick for I’ll look at that too

[Stazi]

Go to harbor freight and buy the vacuum gauge. It comes with a plug you can insert into the dipstick, then do a vacuum check on it at 2000rpm. You should have around 3-5 inHg. That will tell you for sure what the hell is going on. The gauge is only $14.99 without their coupon.


https://www.harborfreight.com/Fuel-P...ter-62637.html


Sent from my iPad using Tapatalk

[lumberwood]

Every code but one indicates possible incorrect fuel pressure. If vacuum checks out, worth verifying fuel pressure is ok too.

[Copemint]

Check the follower behind the HPFP.


Sent from my iPhone using Tapatalk