Clio 182 Misfire and Arcing HT leads - video in here!

daelo

daelo

daelo

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So basically the car is misfiring intermittently and I think its related to water issues. The video shows the HT leads sparking or arcing on the coil pack body, the HT leads themselves are about 30,000 miles old but the car gets driven 2.5 hours a day so gets quite a lot of use, car is currently on 128,000 miles and due a cambelt/dephaser/aux change imminently.

What are the symptoms of the car doing this? It hadn't been driven since Wednesday evening, come Friday morning hey ho it barely starts! It only seems to happen if the car hasn't been driven for a day or so, could water be getting ingress or just general moisture issues?

I read around a bit and decided to spray WD40 onto the leads while they were off and also on the contacts, this then fixed the problem and the car started after a bit of a splutter and then has been running normal, no more arcing!

Thoughts please guys?
 
I believe they are the Renault specified ones which are NGK, they were fitted by a specialist in Brenchley (Tonbridge recommended off cliosport) after one of them stripped a thread and a helicoil needed to be installed.

This was at the same time the HT leads were replaced, so plugs and leads around 30,000 miles ago, the HT leads do look a little "green" when unplugged, does that mean something?
 
Uh oh, coil pack, spark plugs and ht leads could well be over £150 if not more, not sure how much genuine coil pack is ATM.

I've been told spark plugs should be good for 50,000? Is it more likely to be a fault with the leads contacting with the coil pack due to WD40 fixing the problem?

Want to eliminate the erroneous bits one by one!
 
I'd try just giving the contacts a good clean up and making sure you've got the best connection you can get before going out and buying new parts.
 
Clean them up with a small wire brush I suppose and a bit of brake cleaner/degreaser? The contacts are a little green (i assume copper so oxidizing)

HT leads from ECP are stupidly cheap which makes me question the quality, renault I think are about £50. I'll start with the HT leads cleaning and go from there!
 
Once it's starting tracking down the HT posts on the coil it will be more prone to keep doing it. At a minimum I'd change the HT leads and coilpack, but you must check the spark plug gap as well, since an excessive gap will make this problem much worse.
 
Looks like it's getting a bit damp.

If you don't want to spend money replacing parts, take everything apart and give it a good clean with WD40. Buy a tube of silicone/dielectric grease and apply it inside the boots of the leads at both ends. It doesn't matter if you get a bit on the contacts, the pressure will penetrate the grease. That will keep out any future damp and may well solve the problem completely.

You can also get this stuff which you spray all over the ignition components: http://www.halfords.com/webapp/wcs/..._productId_187211_langId_-1_categoryId_255221 but it starts to look a bit manky on the leads after a while, depends if the appearance of your engine bay bothers you.
 
Change the plugs, 30K is enough.
Clean out the "green" and pretty much follow Blueboy2001's advice above.

Absolutely no point changing the coil pack or leads until you can confirm you have got rid of the water/ damp and corrosion first. You've already said you've "fixed it" with a simple application of WD-40 so it does suggest it's not a knackered pack or lead
 
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