C4 limping HELP!

[Mouka]

Hi Guys- new here and would really appreciate your help. Have below error codes on 2005 C4 2L petrol (EW10) auto. Car starts and drives fine for a short period of time (5 mins or less) but then goes to limp mode. I scanned and cleared multiple times and these codes came up on the last 2 attempts.

P0597 - Permanent Fault - Electrically controlled thermostat Open circuit[/b] (not concerned with this one too much as recently replaced pilot thermostat with self acting )
U0415 - Intermittent - Dialog with ABS or ESP Incorrect Value Received
P0011 - Intermittent - Variable timing solenoid valve locked at upper stop
P0012 - Permanent Fault - Variable timing solenoid valve locked at lower stop
P1160 - Permanent Fault - Throttle position inconsistent, track*1/pressure consistency

after reset and clear and trying again

P0597 - Permanent Fault - Electrically controlled thermostat Open circuit (not concerned with this one too much as recently replaced pilot thermostat with self acting )
P0011 - Intermittent - Variable timing solenoid valve locked at upper stop
P0012 - Permanent Fault - Variable timing solenoid valve locked at lower stop
P1160 - Permanent Fault - Throttle position inconsistent, track*1/pressure consistency
P0341 - Intermittent - Cylinder reference sensor 1 circuit short to negative, short circuit to positive, open circuit

Obviously the P0011, P0012 and P1160 are the common ones that always pop up. So where to now?

Have done following checks:
1) Removed cleaned and bench tested 1920 VVT solenoid valve - all good nothing found strainer clean, spool moves freely under 12V, no leakage to ground, about 9 ohms coil resistance
2) Changed oil (twice) and filter - all good (no oil level or low pressure warnings) - filter good quality aftermarket, did flush between 2 oil changes, no additive on final refill
3) Checked all fuses and sensor connections - both in engine and glovebox nothing found
4) Cleaned throttle body - minor build up of carbon but nothing significant
5) Swapped throttle body with a good one - same issue no change
6) Performed BSI reset - no change (key fob also not working was hoping this would come back post BSI. Fob was working recently but stopped for some reason. Central locking/unlocking works with key
5) Car battery good - 14.5V while running and 12.6V when not running

When car not in limp mode drives fine. Plenty of power, no smoke, smooth idle, no strange noises and starts very easily. I would suspect cam timing is OK. No evidence of belt slipping a tooth.

When car goes into limp mode, idle erratic, loss of power and barely drives at 10km/hr (although still can change gears manually with auto trans. If I reset all codes or not drive for say 1 or 2 days car starts well then seems to go to limp mode. I get less than 5 minutes of driving before limp. Basically the car is unusable hence my cry for help.
Has anyone had similar issue - what further checks could I do. Even my Citroen mechanic is scratching his head a bit. Not keen on replacing components randomly but will do if no other option.
Thanks heaps, I know there is a lot of horsepower on the forum someone will know what to do.
Tom

[Mouka]

Hey guys can anyone help please. I know there are lots of experienced people out there.

[seanrx]

In the Peugeot forum, you ask this also?

More EW10 owners so more help/info. If a repeated BSI reset is not a fix, there is something I did on my own C5.

Remove and refit the shunt fuse with key in 'on' position.
May hear or see a spark on refit. After 10 mins I refit the fuse.
This fixed my tyre pressure warning that was/is disabled but switched back on for some reason.

But this hack could also have caused even more BSI damage, so be careful.

[Mouka]

Hi Guys - another update after some more work over the weekend. Decided to change plugs. Old ones looked not bad - even wear and even colour on all 4. Put new ones in anyway. After reassembly car would not start and starter was spinning the engine a bit faster - like engine had low compression. Pulled coil pack off and removed all 4 new plugs and did compression check. All 4 cylinders were only 95psi!! That is too low. Is the inlet cam phaser playing up and altering the timing of the inlet valves as the only explanation of low compression pressure? Re-assembled everything, disconnected battery for a reset and car started straight away. As if what ever was causing the low compression has reset. I think this is a big clue. Anyone else experienced this? Is my dephaser or vvt solenoid not working correctly? Would explain the error codes i guess.

[liquidhandwash]

I would get a OBD tool that can read the live data, so you can check the TPS, and other sensor signals are getting to the ECU, as it could be a wiring or earthing fault.

[Mouka]

Thanks for the reply liquidhandwash - I have access to OBD tool with live data. I was more confused about how the engine can have low compression one minute and the next everything is fine. Sorry what is TPS?

[Mouka]

Hi - I have replaced the Throtle Body with a known good one OEM quality same part number. No difference in behaviour so I concluded it is not the TPS causing the fault.

[Mouka]

I have completed another compression check and all cylinders even at about 95psi. I have also borescoped inside the cylinders and bores are really good with prominent cross hatch still visible and no scoring marks. I am concluding the low compression pressure during cranking (butterfly fully open) is due to valves being open or inlet valves timing affected by VVT phaser or faulty hydraulic lifters (unlikely as all lifters nice and quiet when engine running smoothly). Does anyone know what the cold cranking compression pressure should be on a good working engine? I think it should be 160-180psi.

[Mouka]

I have done another cold compression check and consistently get 95psi on all 4 cylinders. I am starting to think this is normal. Any thoughts or experiences?