Toxic Fumes Warning Light

[Chris]

Right, my toxic fumews warning light has just come on on my 04 plate 1.6 Megane. It started juddering really badly, stalling, poor acceleration, smell of rotten eggs etc. The only problem I have is that I am away from home. The second hand dealer I bought it from has given me a 6000 mile guarantee, so it would be covered, but they would have to recover it from oxford back to sussex. My question is, could I drive it back to Sussex so they can look at it next week? Stupidly, I havent got around to getting any AA or RAC cover etc, as I have only had the car a month!

Any help appreciated!

Chris

[Jonault]

If a coil has gone, you will wreck the catalytic converter if you drive it too much.

[Chris]

Seen as it only started this morning, would 150 miles back home be ok? I spoke to the garage earlier and they recon it will be fine to drive it home, and it wont affect my guarantee, so will hopefully have it booked in on Monday.

[Jonault]

Get the garage to test the emissions once they've sorted the coil. If it fails the test, they should replace the cat for you being as they advised you to drive with a mis-fire.

[Chris]

Cheers for that, I will. They can't book it in until Friday, so will get on to them about a courtesy car!

[Coullio]

My wifes car has developed the "Toxic Fumes Warning Light" I have disconnected the ignition coils 1 by 1 and it made no difference. I searched on Google and someone had a sensor cleaned & reseated and the light went, could it be this?? Any help would be great, feel free to PM me.

[Sally Kelly]

DO YOU KNOW WHICH SENSOR WAS CLEANED AND RESEATED FOR YOUR WIFES CAR.
SALLY

[Jonault]

It was probably the TDC (Top Dead Center) Sensor located on the top of the clutch bell housing. It is hidden by pipes but it's job is to pick up on a hole in the edge of the flywheel to inform the ECU when to fire the spark plugs. This sensor can be impaired by dirt flying around in the bell housing so cleaning can cure the problem. This sensor can also fail and may need replacement.
The Lambda sensor (on the exhaust pipe) can also affect the running if it fails or the connections become corroded.

[AlunWJS]

Good afternoon all. I've been a long time observer of this excellent forum, just keeping a check on all of my Meganes various aches and pains and thought it about time to add by tuppence worth on this particular issue.

I've got an 04 plate 'Sport Tourer' (Estate) with the 1.6 VVT engine. Owned from 1 year old (8,600miles) to the present (31,000) miles. In this time I have had NO serious issues, but a few niggles, mostly sorted under warranty, except for the good old toxic fumes light which has never been resolved.

I first experienced this about 1 month into ownership and have pretty much had it constantly throughout. I've only once had a coil completely fail (the symptoms of which are pretty obvious), mostly the problems are very subtle. It's been back to my local Renault garage on many occasions and also to a couple of independents. They always plug it in and say a coil has failed - Think I've been through about fifteen of them now - I'm convinced it's not a coil failing per se, more likely something else is wrong that is causing the coil to fail, but of course they can only do what the computer tells them so the problem never gets fixed.

So - the symptoms?! Well, the car starts and drives absolutely fine. No issues at all, except briefly when the problem occurs. The problem only ever occurs when the engine is fully warmed up and idling. When the engine comes to idle the rev counter sits at approx 800 rpm. After a couple of seconds it drops to below 750 and the familiar judder kicks in. The revs don't drop further than halfway between the 500 and 750 rpm marks but the needle flutters slightly. After a few more seconds the familiar light starts to flash. Revving the car up to about 1200 rpm and holding it there for a few seconds clears the light and the car drives fine. If I pull away with the light still flashing then there is no perceivable loss of power, it pulls away with no issues and the light goes out after a few seconds of normal driving.

Now, to complicate matters slightly! When this problem first occurred (May/June 2005), I was convinced that it only happened if the air-con was off. I've since noticed that now the weather has improved, if the ambient temperature is above 17/18 deg C then this fault doesn't occur (which I'm thinking could explain why I believed it was linked to the air con initially?!). At warmer temperatures, when the car idles it idles at a slightly higher speed (850ish rpm) and stays absolutely rock solid at this speed. I've left it idling for many minutes at this speed and there has been no indication whatsoever of a fault. Once the outside temp drops to about 16 deg C then the problem is back.

Now for the questions:
Do these symptoms match anyone else's? Particularly in regards to the engine speed and temperature observations?
Has anyone ever successfully had this problem fixed?
Has anyone had a diagnosis that isn't 'a coil has failed'?
What is the 'correct' idling speed for the 1.6 engine? And, is it possible to increase the idling speed to say about 900rpm? (If I hold the throttle so it's revving at 900rpm when stationary then the light never comes on).

My local Renault are a bunch of complete cowboy muppets (that's another story), and have whilst under warranty (in addition to an awful lot of coils) changed many spark plugs, cleaned the throttle body and normally insisted that there is no fault. Now it's out of warranty I'm not going near them again, but I'm pretty fed-up as I'm certain that there is a niggling electrical fault with the car that's never been properly diagnosed! Yes, I should have been stronger with Renault Customer Services, but live and learn I guess.

Sorry for the ridiculously long post, but thought it important to try and get the facts down as accurately as possible. If anyone has any feedback on this I'd be very interested to hear it!! Perhaps we should start up a support group for poor sods with irritating flashing lights!!

Alun

[AlunWJS]

In addition to my previous post, meant to add that it always seems to be cylinder three where the problem occurs. Does anyone else have a 'favourite' cylinder where their fault is occurring?

Also, as part of my 'live and learn' experience, a little while ago I went to an independent garage (nationwide autocentres) for their opinion on this subject. The man there diagnosed a failure on coil three (no surprises there), but then talked me into having all four coils replaced as apparantly 'a failure in one can cause a knock on effect' and other coils can then fail. This was my first 'out of warranty' experience and I didn't know how much a coil was. I thought about £40. He charged me £80 per coil!!!! Justifying it as they were 'genuine Renault parts'. I agreed to this on the conditon that he guaranteed that he would fix my fault (knowing in my heart that it wouldn't) Well, needless to say the problem came straight back. He referred me to a different Renault garage who concurred with the diagnosis of a fault on coil 3. To make me feel like a complete fool, he then said that the genuine Renault part was £43 inc VAT, and not only that, but the four coils fitted were 2006 parts (grey tops) and not covered by warranty. He fitted a 2008 coil (brown top) to cylinder 3. Low and behold...problem came back!! £300 refund is 'in the post!', and the car will be going back to the newly recommended Renault garage, unfortunately a bit of a trek for me, but they have at least shown an interest in fixing the problem without charging me loads of money just to diagnose a 'failure with coil 3'! (my local Renault garage want £100 just to plug it in!!)

[Emmabunny45]

Hi all

I've got a 1.6 16V 2004 Megane that I've had since December 2006. Had no real problems with it until January, when the electric windows mysteriously opened themselves and stuck in the down position. Even out of warranty, Renault fixed it and just charged £19 apparently for the part.

Since then I've had 3 problems with the Toxic Fume filter light. The first time I had the flashing light and got the eggy smell and bad performance so immediately took it to the Renault delaer who replace an ignition coil (just the one) and presented me with a bill for £100. At the same time the car is making really bad squeeking noises all the time when driving and also when braking. Renault said they didn't know what it was but said something about the brake pads (or disks?) binding and said they could separate them for another £100 but couldn't guarantee it'd fix the REALLY LOUD squeeling.

9 weeks later the toxic fume filter light came on again, but this time without flashing and the 'SERVICE' (not spanner) light was also illuminated. The car also started stalling every time I slowed down. This time, Renault said it was a faulty camshaft sensor and charged me £200 for the repair.

2 weeks later the same lights came on again, although the car was driving well (besides the REALLY LOUD squeeling noise). Thinking it was the same fault, I took it back to the garage. This time they said it was a faulty heater thing on the downstream oxygen sensor - and wanted £200 to fix it. This included the service charge FOC! The man said it was to do with the emissions and that it just meant that the car would fail the MOT. I asked if it was safe to drive and he said it was, but that I should get the work done sooner rather than later. I took it to an independant garage (owned by a friend of a friend) who's computer diagnostic thing couldn't trace the fault. He replaced the part that Renault said needed doing but couldn't reset the warning light. He then took the car to another nearby garage with more sophisticated diagnostic equipment but their computer couldn't recognise or reset the warning light either.

Is my only option to go back to Renault? I know they'll charge me £60 to hook the computer up and I just know they'll find something else to charge me for!

Thanks very much in advance. I love my Big Bum but am near the end of my tether with it!

Emma

[wanda]

call me nutsy but does this only happen to petrol engines?

[grahamjrocks]

is it possible to reset the service light and toxic warning light without visiting a dealer i have just replaced all 4 coils myself(10 mins and a 105 from europarts) but both lights are staying on

[Emmabunny45]

Funnily enough, since my last post - my lights have gone out. The only explanation I can muster (being entirely non-technical and wouldn't know if it is normal anyway) is that I filled up at a Shell and put some good stuff in, I've usually used supermarket rubbish. Now that the good stuff is in the car, the light went out. My fault was to do with the downstream emissions sensor so maybe now that there aren't such bad fumes from the crappy supermarket stuff, the light turned itself off. Maybe.

[Robynblack05]

Hi everyone, this is my first post so bear with me but basically i need advice!
I just picked up my brand new megane 1.6 3dr today was very excited. drove about 40miles and now toxic fume light is on and has been on the last 10miles of my drive home. I have just gone and started the car again and its still on... been about an hr now!
Ive called AA who are on way but from reading all the previous posts i am very worried.
Why has it done this and is this a continous problem i will have?
Also how come so peoples flash whereas mine is staying on???

Thanks,
Robyn.