Peugeot 308 - 2010 1.6L THP 115kw problems

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tkkdgale

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Tadpole
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Gday All,

Just picked up a first car for my daughter. The car has done 85K klms' and drives pretty well - it's in pretty good nick as far as I am concerned - but, as expected being 2nd hand, there are a few issues. I'm hoping I might be able to tinker away over time and resolve a few. I am asking for people's experience to help see if I can narrow down a few likely causes for the below:
- P0420 error code (converter efficiency low bank 1)
- Blows what looks like white smoke from exhaust and seems to smell like fuel (not thick or heavy smoke, but visible when you crouch down to look at exhaust outlet)
- Black "sooty like" coloring on exhaust pipe outlet
- After idling for a few minutes and give it a good rev, big plume of blue smoke from exhaust (no blue smoke while normal running and none at start up after the car has been sitting for a few days)
- Oil puddling/gathering in recesses in Turbo inlet hose, as well as in the ridges of the boost hoses in/out of intercooler

Wondering if there is a common theme here - running rich or leaking injector OR burning a bit of excess oil (or both?) will create the issue with the cat not being able to do its job propely and throw a code

If anyone can help shed any light and offer some experience or opinions I'd appreciate it.

Thanks

Tim
 
A few things come to mind. Converters are very expensive and the computer is warning you it's endangered. Some possibilities--

Defective catalytic converter - ie too late)
Damaged oxygen sensor
Oil contamination in the converter
Exhaust exhaust system leaking above the converter
Wrong fuel (eg leaded fuel )
Rich/lean mixture generally (damaging the converter)
Misfires (as above, damaging the converter)

But I wouldn't start with the expensive converter.

Have you noticed any misfires, which may go away for a while? At 85k km the engine may have clagged up inlet ports, particularly if low SAPS oil wasn't used. Crap blockage, which is extremely hard, leads to air/fuel ratio errors which may have no error codes. Less air means unburnt fuel.. Cleaning is a subject in itself, often discussed here.

Can you read the output from the upper oxygen sensor?

The original user books specified petrol engine grade oils. Lately the advice is to use oils specified for the HDI engines to minimise ash deposits. The oil in the air supply is a mixture of recirculated engine blow-by, and turbo bearing leakage. Direct injection engines don't have petrol washing the inlet valves.

Excessive oil is the next investigation - the engine cover valves and the bearing. Sometimes the oil can pool excessively in the intercooler.
 
Last edited:
What fuel are you using? Minimum 95 is required. Don't use E10.
Do you know what oil is in the engine and when last serviced? Does it have a service history? Inlet clagging is a common problem.
When it idles, what happens when you remove the oil filler cap? Whistles? Very strong vacuum? The engine cover also recovers oil, so it may have a failed diaphragm inside and need replacement.
Are there any cracks in the turbo inlet hose? That is quite common. There are early and late versions that connect differently to the engine cover. The turbo itself usually lasts well, but the pivot on the wastegate can wear badly and the wastegate valve then doesn't close properly.
 
David S said:
What fuel are you using? Minimum 95 is required. Don't use E10.
Do you know what oil is in the engine and when last serviced? Does it have a service history? Inlet clagging is a common problem.
When it idles, what happens when you remove the oil filler cap? Whistles? Very strong vacuum? The engine cover also recovers oil, so it may have a failed diaphragm inside and need replacement.
Are there any cracks in the turbo inlet hose? That is quite common. There are early and late versions that connect differently to the engine cover. The turbo itself usually lasts well, but the pivot on the wastegate can wear badly and the wastegate valve then doesn't close prop
Click to expand...

seasink said:
A few things come to mind. Converters are very expensive and the computer is warning you it's endangered. Some possibilities--

Defective catalytic converter - ie too late)
Damaged oxygen sensor
Oil contamination in the converter
Exhaust exhaust system leaking above the converter
Wrong fuel (eg leaded fuel )
Rich/lean mixture generally (damaging the converter)
Misfires (as above, damaging the converter)

But I wouldn't start with the expensive converter.

Have you noticed any misfires, which may go away for a while? At 85k km the engine may have clagged up inlet ports, particularly if low SAPS oil wasn't used. Crap blockage, which is extremely hard, leads to air/fuel ratio errors which may have no error codes. Less air means unburnt fuel.. Cleaning is a subject in itself, often discussed here.

Can you read the output from the upper oxygen sensor?

The original user books specified petrol engine grade oils. Lately the advice is to use oils specified for the HDI engines to minimise ash deposits. The oil in the air supply is a mixture of recirculated engine blow-by, and turbo bearing leakage. Direct injection engines don't have petrol washing the inlet valves.

Excessive oil is the next investigation - the engine cover valves and the bearing. Sometimes the oil can pool excessively in the intercooler.
Click to expand...
I have a basic autel reader and the Oxygen sensors look to be working. Upper sensor voltage goes up and down as expected, trouble is that the lower one does as well - when it should stay relatively stable around 0.5V
No misfires, the engine runs well.
I have considered that the oil may be getting sucked in to the turbo inlet from the PCV but will need do something to confirm......... maybe a catch can in-line to see how much oil it gathers?
 
The lower one was covered in soot so used a MAF cleaner to give it a spray clean.
I also ran a dose of a catalytic cleaning agent in the fuel to see if that would help.

The fuel is the 95 octane, previous owner told me to use at least that grade. Good service history but would need to look at paperwork to see if it states exactly what oil was used.
When the oil filler cap is removed there is a distinct change in engine idle/pitch/sound and there is a vacuum on the cap as i pull it off.
The wastegate pivot shaft is worn, I can wobble it around a bit, and there is a leak at that point. I put air up the exhaust pipe and blew air through the exhaust system, then used a "suds" bottle and sprayed all over the exhaust. There were decent sized air bubbles at the wastegate pivot.
No cracks in inlet pipe, I've had that off and it is in good nick.
 
Couple of updates, after taking the vehicle to be checked out:
- P0420 code is because one of the previous owners has removed the cat converter
- PCV is buggered, sucking bulk fumes and oil through the iturbo and inlet, so I need to replace the rocker cover
- spark plug in cyl #3 is cleaner than the rest (like it's been "washed"), he's suggesting a coolant leak either from a head gasket or cracked head. This one is interesting, because it doesn't have a misfire and there does not appear to be any exhaust gases bubbling back through into the header tank...... could a dogy injector cause the same thing?
 
Maybe, someone changed only plug #3? It happens. Clean them all together or replace the set and see how they travel before tearing it apart. If it is leaking coolant into the cylinder, the coolant level will slowly drop with use.

You can buy aftermarket wastegates via Aliexpress, but make sure the flange is the same as your car. There are two versions - flat and a one with a recess for the seal. If you can weld, you can buy just a 'flapper' valve repair kit (for K03 turbo) and repair your wastegate housing. If you end up removing the turbo and manifold to do that, get some new nuts and bolts first and also consider a braided turbo oil feed and improved drain - refer Mambatek.

You could replace the engine cover as a first step and look for a good used catalytic converter. The genuine engine cover is the best option (dealer or EAI / Dapco) as the aftermarket versions are hit and miss as some do not quite line up to all the plug holes. Further, this video on Youtube is showing how one of the valves inside an aftermarket cover did not seal and needed modification:
 
There are early and late versions of these and the associated turbo inlet pipe. The difference is where they connect. Early is just a hose and late clips together. You may need to get the later hose as well. Check what your car has now. I have seen just the hose part sold separately as an aftermarket item via eBay and Aliexpress.
 
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