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

[silencer51]

It seems that a lot of 1,6 MegII owners have the following problem.

When it's cold outside and the car has been stationary for more than 5-6 hours, one can feel a momentary hesitation when first pulling off, at the 1200-2000 rev range. The engine revs normally, yet it feels like it has no power for a moment or two.

This happens in the first couple of minutes after you turn on the engine, if you wait a little bit for the engine to warm up the problem will not manifest itsself.

On many cases, this happens only once in say, 4-5 times.

Apart from this, the engine performs and feels like it should. Fuel consumption is normal, no weird noises, no power loss, everything works fine EXCEPT the above mentioned problem.

I know of owners who have had the dephaser pulley replaced who still exhibit the problem.

I have also replaced the engine coolant temperature sensor on my Meggie, to no avail.

I also know of members who have this problem and have checked their dephaser angles via the CLIP only for the angles to appear perfectly normal, throughout the entire rev range, and even when cold-starting the vehicle.

Surely this problem can't be the dephaser then, can it?

It's not the ECT sensor too.

If it is a characteristic of the engine, why has no one made a fuss about it (magazines etc.)?

Apparently some cars are affected and others are not.

So please vote on whether your car exhibits this symptom or not.

[MrAsia]

Mine seems to run fine.

[soterman]

Voted yes,

I have the exact same symptomps. When cold-starting and the temp is below 15 celcius, my car accelerates from 750 to 1500 rpm just fine, then it 'hesitates' until 2200 rpm, and then it picks up the pace again.

If I warm up the car (stationary) for 3-4 minutes, then it accelerates without hesitation from 750 to the redline.

[silencer51]

Ah, it would be great if we could compile a list of the dephaser symptoms and the corresponding faulty parts...

Many of us are out of warranty and can't afford to pay almost 1000 euros for something that is not 100% guaranteed to fix the problem...

Is the "morning hesitation" (as I like to call it) caused by a software glitch? A faulty sensor? The solenoid? The pulley?

Unfortunately it seems the possibilities are endless...

[clembo]

hi i have the samr problem as silencer 51 had the dephaser pully replaced ok for a couple of days then came back ,am still in the "frame of mind"so to speak! as weather to take it back to the dealers(mine being a 53 plate) jury is still out on this one!

clembo

[kmarty]

Same problem (Megane purchased on Aug 2005)

P.S.: Where I find number which you write as "XY plate"?

[Colum Mc]

I used to hit a flat spot for a second or two with my or megane, was down to spark plugs which were changed and problem nearly solved even though the plug wasn't required for another 10,000 KM's.

[silencer51]

It seems that quite a few people have this particular problem...

The temps here in Greece have dropped drammatically in the last few days (they are around 10 degrees celsius) and the problem has become
more pronounced...

Let's assume, for a moment, that it is not a faulty dephaser...

Let's also assume that it is not an old ECU software glitch (even 2005 models exhibit this)...

It's not the ECT sensor...

What then?

The funny thing is that the engine starts normally, idles fine and revs freely from idle to the limiter... It just feels kinda breathless for the first couple of minutes - you can sort of avoid this if you rev it very, very, very gently and change gears below 2000 rpm, but it's frustrating driving a 2003 car that behaves like a 1970s one with a faulty choke...

[steves]

I have kind of noticed this recently (since we moved house) with our 2003 Megane 1.6 VVT.

Mainly noticeable because 300 metres from our new house is a busy roundabout - the kind that requires you to pull out in to a sometimes small gap between two approaching cars.

You're right, the car initially seems to pull fine and then momentarily there's no power (by which time I've pulled on to the roundabout and there's another car heading straight for me )

I put it down to the fact that the car had only travelled 300 metres down the road and was cold. Isn't it still the case that even modern cars need to warm up before working optimally?

Although I have to say that I don't like the fly-by-wire throttle in our Megane, or rather that it seems to try to drive the car for you on occasion (hate that kind of "the computer knows best" intervention!).

So far as I'm aware we've never had any sensor problems, or any dephaser pulley issues (it has had a new ECU, and new coil packs though - both under warranty thankfully).

[silencer51]

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.

Yesterday, I started the car up, and pulled away without waiting for it to warm up etc... no noticeable problem.

Today, there was a noticeable power loss/flat spot in the 1000-2500 rev range when pulling away from cold...

Same temperature, different days, different outcomes.

Update: I checked my injection software version today, it's 7.73 so according to TN4432A this is not the cause of the problem.

The solenoid valve also checks okay...

So:

Candidates for said problem:

-Dephaser pulley (weird because there is no noise upon startup, or a drop in performance, or any other indication of a failed pulley)
-O2 sensor, the one close to the engine, perhaps it is sending a wrong signal to the injection computer when cold (and thus should not function)?

Prices:
-Dephaser pulley & new timing belt & accessories + labour = almost 850-1000 euros.

-O2 sensor, relatively easy to replace, 150 euros for the part + labour

I really can't think of anything else...

Funny thing is, a few members have had their dephaser pulleys replaced, yet said problem remains...

What's going on?

[vijay488]

I had a friend who took Meg 2 injectors and fitted them to his Megane classic, and he told me that he got the flat spot.

I have the same flat spot in my Meg 2. Since I'm out of warranty, I'll try to get a set of Megane Classic injectors, and try them out.

[bloomer.fsnet.co.uk]

I also have a 1.6 Megane 11 on a 03 plate that is exhibiting similar problems, but this is coupled with a tendancy to stall after about 10 seconds. Starts again ok but does the same untill engine has warmed up. During this period it has the hesitation at low revs and in morning traffic progress can be a bit jerky - not a pleasant experience.

Problem suddenly appeared at end of September after car was parked up during my annual holiday, a few days later the Service light and engine management light came on. As car is out of warranty had the fault code read in my local (not Renault) garage, they said it was Camshaft position sensor, or possibly - but less likely - the dephaser solenoid. Both were changed and fault code was cleared. I now have no warning lights showing but the stalling and hesitation remains.

I found this website in my desperation for help as Renault say they can do nothing until I spend £65 on a Clip test with them - but if there is no fault code to read, what is the point??

Now I find this website full of other owners with a similar "undetectable" and "unresolvable" problem. Can any one help ???

I managed to get the dephaser changed in June under the warranty, it only had days to run, after complaining about strange noises and poor performance for some time, after this it was going well - but no more.

I have also had to have an ignition coil changed, my front discs squeal constantly, the back ones and pads were replaced as they had corroded badly - all seem to be common complaints on this site.

Someone must know something!!!

[DEEJAY1976]

i have a cc 1.6 and this happen every time the cars temp gauge is around the cold mark, it splutters for about 10 sec and then its normal again, been in the car trade ive found out that renault dont know what it is and all the can offer to try and cure the fault is to reset the ecu, a friend has been to renault (reg vardy mbro) 5 times and each time they just reset the ecu but the fault is never fixed!!! so i just live with the fault

[moonman5]

I have this same problem on my 54 plate coup cab 3,500 miles, the car is garaged every night yet it still seems hesitant on pulling away first thing, also this is the first car I have ever had that I stall so much! now dont get me wrong I am not unfamiliar with clutch control? I can confidently get in to any car and pull away almost imediatly even though I am totaly unfamiliar with the car, But my Meg seems to bite me back and stall unless I give it a handfull of "unnesary" revs?

[silencer51]

Get the dephaser pulley replaced.

Today I had the following done to my car:

-Replaced tensioners & belts
-Replaced dephaser pulley
-Replaced water pump (better safe than sorry, it costs 60 euros)
-Replaced lower engine/gearbox mount
-General inspection

The engine mount must have snapped on one of my track days. The only evidence of the problem was a slight movement of the gearbox lever on pulling away and braking. It's rock solid now and gear changes at lower revs feel more smooth.

About the pulley, first impressions: lower fuel consumption, better performance in higher gears and revs, normal engine idle noise, and it seems that the cold start hesitation is gone - I still need to test at lower temps though...

All this typically costs almost 900 euros. Thankfully the chief tech at the dealer was most helpful, he spent 1 whole day talking with Renault Greece and managed a hefty discount. The dealer also gave me a separate discount, even though this was the second time I've ever visited them!

I ended up paying 450 euros. Could be much worse, methinks... (I'm 1,5 years out of warranty).

Dare I say the chief tech there was a Greek version of WebCode... He was helpful, informative, acknowledged all the problems I mentioned and was, above all, friendly. Bravo!