1,6 K4M VVT Problem (Hesitation when cold, loss of power)

[silencer51]

No, I've been out of warranty for a year and a half now...

I have done a couple of emissions test on my car though, and they came out perfect... So I'm guessing the oxygen sensors work fine?

[fennomegane]

It is true that even modern cars will not operate at 100% when cold.

However,this should not be that noticeable to the driver - there is a definite flat spot there, on a few occasions it causes a 'hiccup' when pulling away...

For example, the last few days temps here in Greece are around 10-11 degrees celsius.

The temperature in Finland has been about -13 C few days ago and no problems. My new Megane is working as good as in summer, no difference. Few winters ago the temperature was about -35 in winter and my previous Megane Break 1,4 16V 2001 did work just fine. Excellent car in winter, although not the warmest one. I used the car with and without pre-heating system and it did start everytime with no problems and did run just like in summer.

Maybe the problem is humidity, not temperature? In my experience modern cars operate just fine when it is cold. 10-12 C temperature is quite high comparing temperatures in winter in Finland

[silencer51]

Who knows... It could be humidity, but unfortunately this is one problem where you practically have to replace the engine for it to go away... And that I am not willing to do.

I really, really hate saying this, since I like my Megane, but the option of selling it and getting something made in japan is looking better every day...

[meganeboy]

all makes have their disgraces..... buying from Japan, China, Italy, Germany..... all have defective cars, unfortunately!

[silencer51]

Of course they do.

In my opinion, all European carmakers are at the same reliability level - be it a VW, a Peugeot, a Renault or an Alfa...

However, the Japanese are on a league of their own... Just check any reliability survey (and yes, we have japanese cars in the family, none of them have needed anything more than oil changes and bulbs... My father's Subaru has 80,000km on it and the only problem so far has been a broken plastic switch).

But don't get me wrong - I don't have a problem with the reliability of my Megane (I've had very few problems, especially compared to some other unlucky members). What I have a problem with is with a fault that cannot be traced and seems to be a 'feature' of the engine!

[bloomer.fsnet.co.uk]

At last, my stalling and hesitation problem seems to be solved!!!

After convincing myself that the dreaded dephaser pulley had gone again I tackled the Renault dealer (Abergavenny Renault - South Wales)who supplied the car and also replaced the dephaser under warranty last June. They were once again adamant that they would have to do a "clip test" at my expense (warranty out 5 months ago) before making any commitment but agreed that if it showed a faulty dephaser they would take it up with RCS under the parts guarantee.

To cut it short, they had the car last Friday for 2 hours. They reported a "Fault code" still in the computer - not a suprise as the service and EMS lights were on when it went in - which they cleared and also "hinted" at reprogramming the ECU, I say hinted because when I collected the car I could not get the Service Engineer to confirm it. But whatever they did it worked, no more stalling, no low revs hestitation and very smooth running through the rev range, and to cap it all - NO CHARGE!! "we only removed a fault code from the computer" he said - and that is supposed to take 2 hours? sorry can't believe that!!

Its been a week now, with mixed weather conditions from hard frosts to mild and foggy and I'm still amazed at the difference. Hope it lasts!!!

[silencer51]

Bloomer, it would be great if you could give your dealership a call and ask what exactly was done to your car... It would help greatly all the owners whose cars exhibit similar symptoms...

Do you have any cold start hesitation problems at all now?

[alee_1.6]

i would have just thought it was because the engine was cold!

as u say, when it warms up it goes away?
maybe it just cause the engine is cold!

[soterman]

No....

I had the same symptoms, i.e. hesitation at 1500rpm and then loss of power until 2500rpm, and then I had the dephaser pulley changed and they all went away.... it feels like as if I'm driving another car... well, another engine for that matter...

[kmarty]

No....

I had the same symptoms, i.e. hesitation at 1500rpm and then loss of power until 2500rpm, and then I had the dephaser pulley changed and they all went away.... it feels like as if I'm driving another car... well, another engine for that matter...

Interesting. I have dephaser pulley also changed (reason was rumbling noises few seconds after start), but these symptoms (hesitation, loss of power) 1-2 minutes after start when weather is cold I still have :-/

[silencer51]

Same here, kmarty...

Are we really ever going to discover a solution to this? I'm starting to lose hope, and now that WebCode is gone I don't think that anything short of an engine change will fix this...

[silencer51]

Also, it would be a good idea for everyone with this problem (it seems to me we are not few, judging by the poll and what I've read on other forums) to pester our dealers constantly about it.

They will be forced to contact the headquarters in France. I'm hoping if the phones don't stop ringing, the engineers there will actually try to come up with a solution. So if all goes well we should have a solution in the next few decades... :-/

[silencer51]

No....

I had the same symptoms, i.e. hesitation at 1500rpm and then loss of power until 2500rpm, and then I had the dephaser pulley changed and they all went away.... it feels like as if I'm driving another car... well, another engine for that matter...

It just occured to me... Soterman, if I remember correctly the dealer also reprogrammed your injection computer with the latest firmware... right?

If so, what version did they flash? Could the solution be the newest injection firmware?

[Oliver]

Same here, kmarty...

Are we really ever going to discover a solution to this? I'm starting to lose hope, and now that WebCode is gone I don't think that anything short of an engine change will fix this...

I had the same problems "...hesitation, loss of power 1-2 minutes after start when weather is cold...", then I changed to the double platinum spark plugs of the 165hp 2.0T (NGK PFR6G-9, Renault-No.: 82 00 363 384) and it became much better. Alternatively normal paltinum type NGK BKR6EVX, or high-end iridium NGK BKR6EIX-11 surely also will work or any other brand platinium or iridium types.

(But I wouldn´t use mulit ground elektrode sparkplugs like bosch super4 or beru ultra-x or any other kind of exotic geometry (e.g. brisk))

The thinner center electrode of all these platinum / iridium sparkplugs provides a stronger spark and so better ignitability even at the very late ignition timing as it is used for catalyst heating in this engine.

[silencer51]

Thanks for the info Oliver!

You own a 1,6 I presume? I will try the spark plugs you mention on my next service...

I take it you are also registered on the German Renault forums? Are people experiencing this problem there?