HT leads arcing?

[Glade]

Serviced the 182 at the weekend. Oil, filters and spark plugs. Also cleaned the engine bay- spray-on, hose off degreaser.

Did 100 miles OK, but now car has a mis-fire.

Checked the HT leads - in the dark tonight, and they're all seated OK. But not sure if they were damp or not.

Read on clio forum that the HT leads can arc to the aluminium plenum (air intake). Does anyone know anything about this. If the HT leads have arc-ed to the plenum, I imagine they are now dead e.g. blown the insulation out and will need replacing.

Any ideas?

(ruled out coil, because this co-incides with me changing plugs. Also plugs are straight from Renault and should be gapped correctly)

[skid-mark]

i would remove the ht leads where they sit over the spark plugs and check, if you've been cleaning the engine they might be full of water or damp in around the spark plug and end of the ht lead, if so dry as much you can with a rag around the plugs and inside the head, then use some wd40 up inside the lead as it traps the moisture from cleaning.

Edited by skid-mark on Tuesday 17th March 20:32

[rev-erend]

I cleaned an engine bay with water..

Just the once.

Never again.

[Glade]

Tried to dry the plugs / leads with a rag today... misfiring worse than ever... backfiring adn an evil smell from the cat.

Took it all apart again and used WD-40 and solved the problem.

Phew - just hope the cat hasn't been too badly damaged!

[rev-erend]

I was going to mention Wd40 .. as it expells water.

[Glade]

More misfiring.... more water found!

going to blow the HT leads out with a compressed air line, then get a heat gun on them to evaporate.

NEVER WASH ENGINE! (its just not worth it!)

[ridds]

Never head a problem myself.

Obviously you never soak any of the electical items.

tbh it sounds like your leads are shagged.

[Glade]

HT leads in a QC oven at 50 degrees all day, compressed air down the plug holes - loads of water down there came flying back at me... all sorted now I hope.

The shape of the features on top of the engine trap water right over the spark plugs. These are under an aluminium intake plenum. Even rinsing gently over the top traps a puddle of water which has then seeped down past the plug caps. All nicely hidden out of sight by the plenum. The plug wells are very deep - it's obvious how it's happened.