The Mégane II Owners' Club

one problem after another with my 2004 megane 1.5 dci 80, my current problem is that when i start the car sometimes ,it idles rough and the whole car shakes... you can even feel your face shaking lol,the engine it self dosent sound too bad the odd bit of noise, though what i dont get is it goes away including sometimes on start up ie . start the car it shakes then after a while it sorts itself out ,could be short or long journey. all i can say is it feels like a misfire then its fine sometimes and some times not (hot or cold)...ive changed the oil,and put wynns injector cleaner into the engine but with no luck any ideas would be great ...would the injector do this .also i bnoticed just once from cold start when i turned the heater on it stoped shaking but only the once as ive tried it again and nothing ...just thought id add this ,and also the car had an injector blow by fixed,,,and ive took the car to renault and they said they dont know whats wrong with the car ..(they fixed the blow by) on injector one then shortly it started the shaking but when i quized them they basicaly said prove it. lol thanks for any help

Did you get any fault codes?

You can DIY check the glowplugs with a multimeter. Also, disconnect the battery earth and then unplug all connectors from glowplugs, injectors, sensors, ECU, and check for corrosion & spray with WD40 before putting it all back. Bleed any water from the fuel filter & also air from fuel line - 'hunting' maybe caused by air. AlexB recommends squeezing the plastic bulb under the window washer bottle (remove plastic cover) and checking for air in the transparent return pipe from the high pressure pump as per the factory manual. He has also pointed out that tiny pin prick holes in the fuel line (anywhere) can cause the problem to recur. You could also replace the fuel filter (might be a straight swap on the 1.5 - on the 1.9 you can just change the element) if the car has a patchy service history.

If that doesn't cure it, try cylinder compression tests maybe.

I'm sure other people will have better suggestions.

i will try the multi meter thing soon and will check connectors etc tommorow thanks for your suggestions though hopefully someones came across the same problem lol and thanks again. oh and no fault codes

Check the upper right engine holder. This could solve your problem

duca00 wrote:Check the upper right engine holder. This could solve your problem

Hadn't thought of that. Engine mounts could well be it.

Also top dead centre sensor might be faulty (if present).

I would suggest it’s an engine mount, i would pay particular attention to the one located beside the gear box as this is the one with the highest stress factor and as a result if gone will lead to a substantial increase in vibration, especially in a diesel motor.

thanks for the comments....... though if it where the engine mounts (not saying it isnt) would it not do it all the time, it shakes at odd times cold or hot ..ive ordered a odb2 scanner to see if i can find anything lol ie maybe a fault when it shakes when i went to renault it stopped shaking lol. i tried checking engine parts today but no luck would a diesel filter do this or worse the pump or would the fuel pump have done it all the time i think its getting worse

Also top dead centre sensor might be faulty (if present...... hopefully it will come up on my personal scanner thingy when it comes

Just read your first post again. Injector blow by? Hadn't heard of that as a fault until I re-read.

Now I'm more inclined to think that something went wrong when they fixed that fault since you mention the trouble only started afterwards. If they used something akin to https://www.uniteddiesel.co.uk/tips-troubles.php ,then all manor of things could have happened. Bits of metal falling into the cylinder is bad, plus the injector and / or feed pipe may have been contaminated or damaged during the process.

You may find the injector is faulty and needs to be replaced - odd that you didn't get any fault codes, but then the dealership might have 'neglected to mention' any and just reset them. Your own code reader might show up something.

In the end, you may have to buy a new injector and have it fitted and coded to the ECU by a (different) dealership.

Let us know how you get on.

i will let you know once the scanner arrives thanks again.

got the scanner and it didnt have any codes to show at that time ,but now started another thread on it as its gotten alot worse lol i think the things about 2 blow oh nand now shows a code lol glow plug thingy open anyways my problem isnt fixed but recently noticed bubbles in both the fuel lines so davelow is on ta somethin will get this replaced shortly just thought id update this just incase anyone else had this problem ill update again if i get it sorted thanks again

Bubbles...
The fuel line operates under negative pressure, so any pinhole or the badly sealed fuel filter can be the cause. Check in the fuel line rubs against anything under vibration.

i thought id update ( i forgot lol ) and yes it was the engine mount though three different mechanics couldnt tell me this.. £150 for a new one fitted.

ulrich100 wrote:I would suggest it’s an engine mount, i would pay particular attention to the one located beside the gear box as this is the one with the highest stress factor and as a result if gone will lead to a substantial increase in vibration, especially in a diesel motor.

+10 Points for me.. (and i couldnt even see the car!)

on a future note dont spray wd40 on glow plugs or spark plugs cause it only fixes them for a very short time and then when its gone the problem is worse than before you sprayed it.