1.6 Megane II Hesitates when Engine Cold!

[hodders]

Hi all I'm new to this site and have recently bought my first Renault car, a 2004 Megane 1.6 Dynamique with 33k miles on the clock, FSH. I've been keeping an eye on a potential problem for a couple of weeks now which is when the engine is cold, the car hesitates up through the gears and struggles to tickover when stationary (it's not stalled yet though). Once the engine has warmed up (usually after a couple of miles) the problem goes away and the car drives fine. Anyone any ideas what it might be before I ring the dealer and get it booked in? One of the reasons why I bought the car was because I was impressed with the reliability of my girlfriend's 55 plate Clio which she has owned for 18 months without any problems whatsoever. As soon as I bought my Megane though she started having problems with her car stalling and it was found to be a temp sensor!! Talk about me jinxing her!!!

[davelowe]

Oh god, not again. Pray its the coils, or if not, most likely the dephaser. Do a search for symptoms - I hope you don't have to send your christmas presents back to pay for the repairs.

Might turn out well - could be something simple..... Odd both cars are involved - are they both VVT model engines?

[hodders]

Hi, thanks for replying and yes they're both VVT engines. My girlfriends Clio 1.4 Dynamique VVT seems fine now after the garage replaced a temp sensor so I'm hoping that my problem will be just as simple! I made sure that I bought the car from a main dealer though so I've got a 3 month warranty and also I took out an extended warranty with Warranty Direct just in case anything else goes wrong after the dealer warranty runs out in Feb. I'm going to try and book it in today so I'll let you know what they say once they've diagnosed it! The problem definitely is only when the engine is cold and so I only have to put up with it for a couple of miles until the engine has warmed up so I'm hoping it's an easy fix!

[IainMW]

Does sound like the Dephaser Pulley

Get the TDC sensor, Fuel injection computer (re-programmed), and throttle body (cleaned) checked out as well. All of these are well known and documented problems on the 1.6vvt engine.

[hodders]

*** UPDATE *** OMG!!! I just took the car to Lookers Altrincham this morning at 9 am hoping that they would find out what the problem is and would you believe it...11.55am I get a phone call from Lookers to say that there is a fault and they will have to replace the Camshaft sensor and the Dephaser Pulley, but also they said at the same time they will have to fit a new cambelt and cambelt kit!! They didn't hang around did they! They originally said that they would do a cold start tomorrow morning and then try it, so I wasn't expecting a phone call so soon. Maybe they just plugged in the diagnostics tool and it came up with the fault? Good job it's still under warranty (only bought the car 2 weeks ago from Lookers Chester) so I don't have to pay a penny out or else christmas would have been cancelled this year! Hopefully the car will be fine now after I pick it up tomorrow, but I'll let you all know if it fixes the problem!

[davelowe]

Well, to say it failed the minute you bought it is lucky. That the garage found the fault and will fully repair it without you incurring any cost is scarcely believable. To find that level of customer care is unheard of! Excellent outcome. I'd use them again!

[hodders]

I've got my car back now and it's been fixed! Apparently when the garage rang me at noon today to say that they had found the fault, the mechanic had already half stripped the engine down so it was ready to pick up at 5pm. The notes on the invoice say "Confirmed hesitation from cold and found cam sensor fault and dephaser pully out of tolerance. Replace dephaser, sensor and timing kit, tested all ok."

So in all they fitted a sensor camshaft £33.00
ACC Belt kit £39.89
Distrib Kit £99.72
Pulley £124.59
Core Plug £6.87
Plug £3.69

and Labour £284.21 Making a Grand total of £545.83 and I didn't have to pay a penny so I can have christmas after all!!

It goes without saying that I would recommend Lookers in Altrincham and Chester if anyone is thinking of using them.

[direstraits]

Nice to hear that the problem is solved! Even nicer when the garage payed for it. Respect!

[IainMW]

I've got my car back now and it's been fixed! Apparently when the garage rang me at noon today to say that they had found the fault, the mechanic had already half stripped the engine down so it was ready to pick up at 5pm. The notes on the invoice say "Confirmed hesitation from cold and found cam sensor fault and dephaser pully out of tolerance. Replace dephaser, sensor and timing kit, tested all ok."

So in all they fitted a sensor camshaft £33.00
ACC Belt kit £39.89
Distrib Kit £99.72
Pulley £124.59
Core Plug £6.87
Plug £3.69

and Labour £284.21 Making a Grand total of £545.83 and I didn't have to pay a penny so I can have christmas after all!!

It goes without saying that I would recommend Lookers in Altrincham and Chester if anyone is thinking of using them.

Result!

Hope you don't have any more problems and if you do Lookers are as helpful?

[markren2004]

nice result..can't help thinking it must have been a slow day in the service dept.
has it actually sorted out your issue ? i guess you'll know for sure by the weekend when the weather turns cold.

[hodders]

Hi, not sure whether it has sorted out my issue yet, although when I picked up the car from Lookers the other day they said it was fixed now. The car still seems a bit hesitant when the engine is cold, but it's hard to say because before you know it, the engine has warmed up and then it drives fine. I think the hesitation is around 1800-2000rpm and I'm sure that I've read another post on hear about a similar problem around those revs?? When the engine does feel hesitant I havn't got my foot flat on the accelerator pedal because I would have just set off from home/work and usually would be in traffic so maybe it's not getting enough fuel that's causing the hesitation?? I think I'll ring the garage again when I get a minute and see what they say.

[davelowe]

You could try cleaning the throttle body. I read somewhere on here that it helps cold petrols.

[hodders]

Thanks for your advice Dave. I am thinking of taking the car back to the garage in the morning because the car still hesitates (or a flatspot) when the engine is cold and then drives fine when it is warm. Other people on this forum have mentioned about the gains from cleaning the throttle body, but I was wondering, if it was the throttle body that was clogged up, wouldn't the hesitation/flat spot still carry on after the engine had warmed up too?

[davelowe]

I'm not an expert on (recent) petrol engines - in fact not an expert at anything for that matter. I seem to recall that some throttle bodies have a choke type cold start bypass or fast warmup mode - that could be the culprit perhaps. Whip the thing off and clean it anyway - won't harm anything!

[AlexB]

Not being an expert I would like to share a couple of thoughts on the subject...

When the engine is hot, it goes into a closed loop mode, i.e. the O2 sensor readings are used to adjust the mixture quality. This sensor needs to be hot to operate. So, when the engine is hot, many problems go away due to the electronics compensating for the parametric faults (dirty throttle, etc.).

Regarding the dephaser. It uses the engine oil to operate and fails through trivial wear. So, make sure that you are running on a fully synthetic oil 0wXX or 5wXX, and that the oil is clean (annual change). Garages often use "minimum spec" oils, which are good for their short and, unfortunately to us all, long-term profits... An option is to use the oil designed for the boundary lubrication; such oils often have VW505.01 or "ester" written on the label. Furthermore, driving in very low revs may also cause wear due to frequent locking-unlocking the dephaser.

Thanks for your advice Dave. I am thinking of taking the car back to the garage in the morning because the car still hesitates (or a flatspot) when the engine is cold and then drives fine when it is warm. Other people on this forum have mentioned about the gains from cleaning the throttle body, but I was wondering, if it was the throttle body that was clogged up, wouldn't the hesitation/flat spot still carry on after the engine had warmed up too?