The Mégane II Owners' Club

Please somebody can offer some advice.The problem appears at low rev.
It is start and uphill running, some stalling .

When I looked back now, I noticed that the problem happened after the changing a air filter.



I changed it for an air filter for petrol cars(#8200371661) which I stocked.
I do not feel the problem at high rev.
Do you think this cause to be a turbo or EGR valve or air filter?

Check MAF sensor connector on the duct directly after the filter.

Thank you reply AlexB.

Because I'm beginner's owner I do not understand the diesel parts. I'm sorry .How look How should I check MAF sensor connector?
Thanks

Did you find it? The sensor is located in about 15cm after the air filter. It could have been disturbed. All pictures are in the manual pointed at in my message in Links section.

By looks of your picture the two filters are different which will provide different air flow I would get hold of a filter for a diesel which should then give the engine the air flow it is set up for at lower rev range

Thanks all.
>AlexB
I read the PDF of TIS.
Is the MAF sensor "air flowmeter sensor"?(at this image #7)


I was able to find that the place where that is located in .
But I was not able to find the page where a way of the cleaning of the MAF sensor connector appeared in.

Is the cleaning method simple?

Thanks again.

Yes, it is #7. I pointed at it only because it is very close to the filter and could have been disturbed when doing the job. Normally the sensor itself does not require cleaning unless any dirt enters the system (never use solvents on it!). I take you've cleaned the filter box with a vacuum cleaner or somehow else when changing the filter... Just make sure that the connector is plugged in and the wires are intact.

I doubt that the replacement filter causes this problem, unless its size is different. It is specified for 1.5dci and 2.0l petrol, so its performance should not be much different, at least al lower speeds.

Another thought. Did you remove the ECU when changing the filter, as specified in the manual? It is not strictly necessary, but the manual recommends it. In this case the problem can be caused by the connectors or something else disturbed during the job. Double check everything.

Please also check other obvious things: the clear pipe to the fuel pump for bubbles, oil level, recent fuel consumption, any abnormal noise, computer messages, electrical faults, etc. Does the car idle well? Does it stall only when going uphill?

I see!.But the petrol engine is different from a diesel engine in an intake system.
I think that the performance will be worse at law speed(rev) if it was changed for the different filter of the air resistance.

How do you think?
Because low speed torque deteriorated clearly.

I checked all tihigs you adviced.]
Idling does not change all the time.The stall does not do frequence.
I never remove the ECU when changing the filter.....
Will a turbo and an EGR valve be suspicious?

Somewhere I read that aerodynamic drag at low speeds increases quadratically with air speed. Therefore, air filter performance mostly affects operation under high revolutions. Correct me if I am wrong.

If performance loss occurred directly after filter replacement, then there is a good chance that these two events were causally related, but how? I never compared these filters, so it is up to you to draw conclusions. Another option is that something was disturbed during installation or dirt/foreign objects were introduced in the intake system. I have already commented on it.

In any case, before investigating further, I suggest to go back to the last known good setup, which means installation of the correct filter or the old one (vacuum clean it before) and checking the air duct in the area of MAF sensor for anything which may cause sensor malfunction (don't spray solvents on it!). Then start checking in the usual manner: visual check, turbo actuator check (it should move within a few seconds after starting the engine), check the clear fuel pipe for bubbles, check oil (near zero consumption + blotter test), battery check, clean the EGR valve and intake manifold, etc. If it does not help, then you should proceed as described in the official manual, which involves specialist equipment.

An option is to use something like this
https://www.obddiag.net/allpro.html
and record live engine parameters for further analysis. Playing with this toy is in my (remote) future plans.

By the way, what other jobs were performed on your car recently and what is its mileage?

Thank you for your giving me much advice,AlexB!!
I checked it in various ways until today, but after all feel it so that it is not improved.
And I have a question more.
I want you to tell a checking method about a turbo actuator and the EGR valve.!!

I add 1.
I noticed that recent fuel consumption turned worse

It is simple.

Look at the linkage of the turbocharger when someone else starts the engine. The linkage should move in a couple of seconds. It is situated between the vacuum actuator and the "hot" part of the turbocharger and it is about 12cm long. When the engine is not hot, you can try moving the linkage by hand. It should not be seized.

In order to check the EGR valve remove the L-shaped thick air duct from the air filter -- wd40 may help. If it doesn't work, then more disassembling will be needed as described in the manual (see Links section of this forum). Close the holes with foil. Then remove the aluminium pipe to the intake manifold, then the EGR valve. All diagrams are in the manual. Use penetrating oil on the EGR valve and plenty of patience. Do not hit it or grab with pliers -- the case may break off the flange. Once it is out -- clean it, then clean two channels from its nest into the intake manifold. Use correct torques (as in the manual) and new gaskets when putting everything back (old gaskets are also usable). Do not let solvents into the electrical part of the EGR valve! The valve is usually dry, but there will be oily soot deposits in the channels mentioned above. See Figure 101884, page 148. It shows the L-shaped duct on the right (2 thin vacuum tubes clipped onto it). The pipe to the intake manifold goes across the picture. The EGR valve is a horizontal cylindrical object behind the lower bolt "4". It has an electrical connector, which is not seen in this figure. Please be prepared to find access to the bolts a bit awkward.
https://meganedoksi.uw.hu/MEGANE_II/MR364MEGANE1.PDF

Having written the above, I am not sure that the problem is caused by dirty EGR valve. As it happened after you replaced the filter, it may be related to what you've done...