Hello everybody! I hope you are all doing fine.
I got a deal on a Peugeot 407 coupe (3 l V6 engine) and I took it as a proyect car. The vehicle was abandoned in a garden since 2015 and it had a lot of turd between the wall of the engine block (spark plug bay and injector bay, see https://imgur.com/a/ssKbzNr ).
I have already replaced the spark plugs, changed every fluid. Spark coils seem to be working fine, injectors are firing (I heared them using a screwdriver) and gas is reaching the fuel rail (pressure not meassured).
Symptoms:
-Weird idling
-Rattling noise at cold start (only at the exact start moment, cranking seems fine)
-Low power on the 1k5 RPM 2k5 RPM range
-Engine doesn't reach +4k5 RPM
-Car shakes on lower gears, specially when reverse is engaged. Using manual mode on the transmition cancels some of the shake
-Check engine is on - depollution system fault
-Codes P1339, P1337 and P1336 are present everytime I scan. No other codes are displayed
-The top engine mount bushing is cracked (it seems it's not even diminishing the engine shake)
I uploaded a video, please don't mind me and my friend talking about how wrong I was when buying the car haha.
https://youtu.be/NW0nxFa4BGU
Forgot to mention, car model is 2007 and it has 80k Km on it (aroud 55 k miles).
The oil I drained out was overdue by a lot but didn't have any anomalies. New oil has only 500 Km on the engine and it's already black as heck.
If the camshaft position sensors are identical and easy to get to, it would be interesting to see if you swapped them, if the problem would move to the 3 cylinders on the opposite cylinder bank.
They are! Will do and update in the afternoon.
I swapped camshaft position sensors and the issue remained. I ended up replacing the first cylinder ignition coil, which changed how the engine performed. This morning I replaced the three coils from the front cylinder bank, which seems to have fixed the issue.
Maybe while I was able to see some spark while testing the plugs the ignition wasn't sufficiently powerfull or consistant enough.
Thank you for the help! Gonna check some minor oil burning in the exhaust manifold now haha.