Peugeot 308 N14 engine Super knock, Hesitation, Weird running., misfire, rough idle and stalls


Peugeot 308 1.6
Dear, All

I have a Peugeot 308 1.6 turbo 2009, my vin number is VF34C5FTf9s144373

I have been having hesitation on light pedal acceleration under 2k rpm and going downhill I get a feels like a misfire. Onload and with aircon on it is worse, but once warm it feels less but I can feel a bit of a misfire/hesitation while driving still.

This all happened in August last year when I had a leaking thermostat housing. I replaced the thermostat housing. At the same time I fixed a timing problem I had by realigning the cam and timing chain, I had a cam/crank sensor align error after that I had no more error. I replaced my catalytic converter with a downpipe also installed a new bigger intercooler and changed my fuse box / BSI.

After that started the car after repairing and replacing all these parts I started getting hesitation and jerkiness when taking off at cold.
And to this day I haven't worked out what it has been yet.

Since August I have replaced O2 sensor, throttle body, vanos, timing tensioner, high-pressure fuel pump, vacuum pump, fixed all oil leaks, new battery, fuel vapor solenoid, MAP sensor, and air pressure sensor, new air filter, new fuel filter.

Then in December, I had a piston blow on me, so I repaired all pistons with new forged pistons, new valves, new valve seals, polished and ported intake and exhaust manifold, no more carbon build-up.

Also replaced timing bolts but not chain, replaced crank bearings and rod bearings, new exhaust gasket. Got it all working again in January but still hesitation and jerking.
Most recently I have replaced PVC and crankcase cover, put in new iridium spark plugs, new OEM coil packs, replaced knock sensor, pulled wiring harness and checked the whole thing too to the bottom, replaced front crank seal, 02 sensor, also replaced all vacuum lines.

Now it's still doing hesitation and jerkiness but less but still there.

I have also done fuel cleaners, done leak tests, pressure test, and compression test, carbon cleaned, smoke test
Also it stalls now and then while reversing and while doing you turn without being on the accelerator.

I'm out of ideas nearly only a hand full of things I think it could be.

Pump in fuel tank but I don't think it is as hpfp doesn't drop and I don't get hesitation or jerkiness up hill or high speed but I have had a misfire going on to highway on hill full throttle so maybe it comes up as a super knock error.

Timing chain as the timing chain I did about 3 years ago was not an OEM on and I wonder if I might be that but can't tell how to test for that.

another thing might be pedal but I don't think so and wastegate way on turbo, now to gateway itself is fine and seals but I wonder if it's the actuator or the turbo solenoid valve.

If anyway has ever had this or has any idea what it could be or how to test would be deeply appreciated because I have run out of ideas
Hello and welcome from the Sunshine State |B

You certainly seem to have left no stone unturned in your effort to track down the fault with no luck.
Have you been able to find which cylinder is miss firing ?
If you change that cylinders COP onto another cylinder to see if the MF follows the CP and if so then you have found the problem / fault.
I have had a quick search of your Pug and note that it has a DI engine so have you had the injectors tested to see if they are flowing properly???
That's right back to December when I replaced pistons I got all new injectors too and I had done the whole cop change and no different and now I have put all new OEM ones I don't think that's the problem etheir
That's right back to December when I replaced pistons I got all new injectors too and I had done the whole cop change and no different and now I have put all new OEM ones I don't think that's the problem etheir
I had a problem with new port injectors that that i installed at a workshop before being dynoed. They were larger than the previous ones and I had a call from the tuner querying what size they were as he was having to add fuel instead of reducing it.

They were removed and tested and 1 was only flowing app 50% .The supplier replaced them and reimbursed me for the additional labour and testing.

The 1000cc injectors that I fitted immediately before driven onto the dyno were an upgrade from 800cc's as they were @ 87% DC @ WOT so that was bordering on dangerous as the boost was being increased by 5psi so more fuel would be needed to keep the AFR's in the right place.

It is generally considered / recommended that the DC of the injectors should be closer to 80% for safety.

TIP I always test thermostats in hot water before installing as over the years have encountered NEW THERMOSTATS that haven't opened properly. Test everything you can for peace of mind.
Thanks for all the information.

Hard to test the injectors as I have no system to test them.

The thermostat good idea I had throught about changing up sensor from old one to see if that was the problem but yeah the test a good idea, it doesn't take long to heat up now compared to old one but fan never kicks in anymore so not sure gets to 90c and then all good stays there the whole time.

I have noticed on spark advance all over the place when I have hesitation jerkness problem so can't put my finger on that one unless it is timing out.

As I say I ruled out the fuel with replace of HPFP and tested and change of injectors, and I made sure same size so I didn't have to tune.

Interesting fact I out the catalytic converter back on for a while and the problem was worse and then just last week put back to downpipe and it's a lot better but not gone.

It's for the problem is when engine on load but now it shows up more, but going up hill with a good throttle open don't feel a thing.

And then put iridium plugs in and new oem coil packs and then going over the wiring from top to bottom.

Other thing is once the car is at temp it's mostly alright with a hick up here and there but compared to when it's cold it's like a dog, reving up and down, down the road even with pedal pushed down full or normal doesn't matter.

The most noticeable is that and the fact the first little bit of the pedal like when throttle opens it does the hesitation.

I'm kind of leading towards thermostat problems or maybe stretched timing chain maybe, as it's a common problem on theses cars.

It's just odd this all started back in August when I slightly adjusted the timing chain timing to get it inline and change thermostat. Only other things I did was a bigger intercooler and downpipe and both of them shouldn't have caused any of this.

I did at the start, cleaned intakes, and carbon cleaned system and Injector cleaner a heap.

It's been a bit of a pig of a pug, up to this point it's been a great car.

I have been thinking maybe getting another thermostat and timing chain.

I'm going to test the stretch on chain next and the thermostat sensor.

Any ideas yourself
Over the years I have removed injectors and had a specialist injection shop that had the machine to flow test then then sonic cleaned then tested @ 100% flow to ensure they were operating correctly.

SA is the only state we haven't visited.

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