Heavy smoke, low power, electric fault

[tomsa]

My 2006 Megane Scenic starts and runs, but very poor. Oil is ok, no oil in water or water in oil. I recorded a short video but not sure how to upload. Like to hear Your suggestions


https://youtu.be/xfLeQoMjQQ4


Bregds
Tom
Norway

[AlexB]

Hi Tom,

The smoke can be oil leaking from the turbo and getting into the intake. This can be caused either by bad turbo or blocked crankcase ventilation pipe. Unfasten the pipe and check if it blows the crankcase gasses. Otherwise, pressure builds up and blows the oil through the turbo seals. It can also be an injector leaking or a compression fault. What does the OBD show? Read the live data from the engine in addition to the fault codes.

Careful, the engine may suddenly start running on the oil instead of fuel. It will be difficult to switch it off unless you shut the air supply or stall it in gear. So, find the throttle valve and prepare to operate it by hand. In theory, 5 taps on Stop button should do the job, but the Electronic Fault may make it impossible.

The Electronic Fault is one of the computers not responding to the CAN bus. It can be either a computer at fault of the bus wire. Check the fuses first, then try to guess which computer is not working by checking which functions are lost. This fault is separate from the engine.

[ttomsa]

Hi and thanks AlexB

I looked the engine over and find several leads or vents from cranckcase, is there one in particular I must check

I also want to change timing belt, waterpump and eventual other items for this main mainetnance

can anyone recomend a KIT or link me to a shop ehere they will know what I must have of good quality


Any recomeddation for a ODB reder resetter aswell?

I seem to have got it wrong too, my Renault say Renault Megane Scenic, in the name. But this forum is just for the Megane?

[AlexB]

The vent pipe is a thick rubber pipe going across the valve cover from the dipstick and into the turbo duct.

The timing belt must be OEM, it comes with the tensioner. The aux belt can be of a good make aftermarket part. For the procedures look in the factory manual in my sticky thread (there exist similar PDFs for your Scenic, although the engine is the same). You will need a special tool for fixing the crankshaft in position and an electronic tool for measuring the belt tension (it's different than in many other engines).

ELM327 OBD tool is about £5 on ebay, it will do the job. It needs to be connected to a laptop or Android device. For any advanced jobs, e.g. coding new injectors, one will need Renault Clip tool, which is expensive (search ebay).

I suggest to check compression and make sure the turbo is good - these can be expensive faults.

[ttomsa]

Thanks again AlexB This is very usefull!

Any advise or link to a serious dealer of OEM parts who might ship to Norway. I assume the price in UK will be far better than possible here.

I should change the tensioner, waterpump, both belts, gaskets and since I have one 2006 and one 2007 (the 2006 one in the Youtube is in addtion to these ) I must save where can to get them on the road again

[ttomsa]

What is the difference between Scenic and Megane? The pic looks just as the Scenic??

[AlexB]

The engine is basically the same, just has a slightly different code. Is it 120ps and no FAP?

Did the car have any oil-related or turbocharger problems in the past? The context of a failure is very important for diagnosis.

[ttomsa]

120ps and no FAP ??

When I bought the 2006 and the 2007 they gave me the 2006 as a parts car, saying it was a wreck? I belived it was the cambelt that had destroyed the engine. I towed it home. When putting it under roof I just tried starting it, never expected it to start but you can see in the youtube. Seems to me that it should be possible to get this back on the road aswell. (untill proven otherwise )

I did take of the vent, ther is some kind of filter or can in the middel? No difference in engine. Belive it might be the turbo since I registered a short try to run/rev up on its own before I stopped.....

As seen in video, trhe front covers including headlamps has been removed used as replacement on another car, it might generate the elctric fault since the leds for headlamp are cut straight off

[AlexB]

The car code is on the oval plate somewhere around the doors, on the B-pillar. This will help to determine what it is.

The small flat round thing on the rubber pipe is the PVT valve. It opens only when there is a positive pressure in the crankcase. Usually it is the oil separator (a plastic bottle combined with the dipstick) which gets blocked.

If the turbo was gone as the original fault, then the intercooler, cat (can be damaged by oil) and exhaust contain oil. The turbo is still whistling a bit (in your video), which means that it did not disintegrate and contaminate the air duct. It is good, as then the duct and intercooler do not need replacing. Turbos are known to fail on these cars as a result of long service intervals and cheap oil used by garages. You can check the turbo by somehow getting access to the cold part and checking play. There should be a small radial play and virtually no axial play. With this smoke, the probability of a turbo failure is high.

When you got the car, what was the oil level? When the turbo goes, it may consume all oil, while revving the engine uncontrollably. This often damages the valves, pistons, or conrods. Check compression, at least roughly, by turning the engine with a ratchet by hand.

[tomsa]

How to get pictures uploaded?

[freelanderuk]

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