REnault Megan 2000 Misfire

[Vincent]

Hi all, Love the vids so thanks ALOT for those.. actually got me thinking about leaving my design job and picking up the wrench for a living… get of that tangent Vincent!

So the car throws up an electrical problem light, the battery symbol and the STOP light persistently flash. That is unless revving hard, they will go out briefly but come on when back to the very rough idle speed. The headlights, clock and any other light flashes the same frequency as the stop and battery warning lights. The problem cylinder is number 3, diagnosed via power balance test (thanks for teaching me that one Eric). I pulled out the sparks, number three is decidedly more dirty but it does still spark with a healthy colour after a clean.

Next step, I am thinking (hoping) it is a faulty injector so I had a listen to them all. Great I thought, number three is not making a clicking sound and the others are.. got to be the problem. Now, for some reason, before making the purchase of a new fuel rail I would just double check the next day as I was in a little bit of a rush the first time round. Unfortunately, I can now hear all four injectors clicking away. What happened, I am thinking I just didn’t put the driver on the right part of the injector before hand. Although, number 3 injector does sound a bit quieter than the others so perhaps it is a bit clogged or has a warn mechanism or just an intermittent fault. The Stop and battery lights are still flashing even when I can hear the injector click.

I have purchased a multimeter and heard the beep on all four injectors to confirm continuity.

What ohh wise ones of mechanical joy should be my next step? Get a compression tester to check the suspect cylinder or just whip out the injectors and give them a good old clean whilst checking they are firing properly?

Thanks for all the pointers in advance, I know my way around a bike but fairly new to cars. Would I need to depressurise the fuel system before removing the rail or can I just go for it with my eyes squinted?

Vincent

Topic

[Daniel]

It could still be either a gasket or bad rings. The texture of the cylinder wall indicates that the rings may need to be replaced. On the other hand, the fact that there is no difference between the wet test and dry test indicates that it may be a gasket. It’s also possible that one lead to the other and both need to be repaired.
Either way the head is going to have to be removed.
If the cylinder wall is actually damaged than the cylinder will need to be re-honed. The cylinder is probably pretty close to it’s maximum possible size. So if the cylinder wall is damaged badly enough, the engine may just be better off scrapped.
Make sure you loosen each head bolt a tiny bit at a time. You don’t want to loosen any individual bolt too much at once cause you could warp the head.

[Dutchie]

What OP is telling, is correct, if it is an IDE engine (direct injection). These injectors have a correction code, just a like a commenrail diesel. This needs to be coded via the CLIP, whitch can be done via Renault dealer. But i doubt that OP has an IDE eninge, i thing he has a good old 1.6 8V.

I would preforme a cilinder leak test, to see if the valve wont be leaking, this was a more commen fault, the reason was the vacumhose the MAP sensor, this was leaking, witch would cause a wrong mixture, witch cause the valve to burn out.

O btw, cilinder #2, is counted from the gearbox side, not from the timingbelt side. 😉 Gotta love the french 😛

[Author]

Replies