Scottish Elises

'Tis a lovely summer evening and I'm in the garage...
Car's running on three.

Changed the spark plugs and leads. There was a problem on number 2, lead arcing to plug (he guesses).

Drive it again, thought it was fixed. It isn't. Barely running. Got towed.

Changed the coil packs. No change.

Pulled the plugs. Number 2 plug has a white powder on the outside.
But number 1 is bent and has zero gap...

Mr Nizzy came to the rescue with a feeler gauge! Gap restored. And it's still on three, his ODB2 reader says misfire on 1.

So new coil packs, plugs and leads. Why has the gap closed, must have hit the piston I guess?

It's off to the local garage I guess but aby more diagnostic ideas would be great...

pete wrote:'Tis a lovely summer evening and I'm in the garage...
Car's running on three.

Changed the spark plugs and leads. There was a problem on number 2, lead arcing to plug (he guesses).

Drive it again, thought it was fixed. It isn't. Barely running. Got towed.

Changed the coil packs. No change.

Pulled the plugs. Number 2 plug has a white powder on the outside.
But number 1 is bent and has zero gap...

Mr Nizzy came to the rescue with a feeler gauge! Gap restored. And it's still on three, his ODB2 reader says misfire on 1.

So new coil packs, plugs and leads. Why has the gap closed, must have hit the piston I guess?

It's off to the local garage I guess but aby more diagnostic ideas would be great...

The plug has closed again?

I diagnose Apeitus anyway.

woody wrote:

pete wrote:'Tis a lovely summer evening and I'm in the garage...
Car's running on three.

Changed the spark plugs and leads. There was a problem on number 2, lead arcing to plug (he guesses).

Drive it again, thought it was fixed. It isn't. Barely running. Got towed.

Changed the coil packs. No change.

Pulled the plugs. Number 2 plug has a white powder on the outside.
But number 1 is bent and has zero gap...

Mr Nizzy came to the rescue with a feeler gauge! Gap restored. And it's still on three, his ODB2 reader says misfire on 1.

So new coil packs, plugs and leads. Why has the gap closed, must have hit the piston I guess?

It's off to the local garage I guess but aby more diagnostic ideas would be great...

The plug has closed again?

I diagnose Apeitus anyway.

Nope

FFS I nearly googled Ape-itus.

It's not closed again (we checked that).

It has been suggested that the wrong plugs have gone in - it has Bosch Super Plus FR6KPP33X-54 and despite my adeptness with google I can't establish if they are wrong (I suspect so - SELOC says +34 as a Bosch model number...

Hmm.

pete wrote:FFS I nearly googled Ape-itus.

I did........still did not get it until the hyphen.

tut

Clean up (and gap if they are wildly out) old plugs and put back in.

Compression test.

Any coolant loss?

Cheers,
Robin

No coolant loss.

Cleaned up and re-gapped, no change.

I can only think that a piston hitting the plug has caused it to close, although the amazing MMC out of hours tech support suggested wrong plugs so I'll need to check that... ('twas the local garage who changed the plugs as they were, well nearer).

I'll check the plugs this morning and failing that a compression test...

ape-itus can be cured by lending me the car for a week.

I'll give it a right good rag, and fix this problem.










*T@C's - car may return with some new problems*

mckeann wrote:ape-itus can be cured by lending me the car for a week.

I'll give it a right good rag, and fix this problem.










*T@C's - car may return with some new problems*

Only an idiot would let you drive their car.
In fact you'd have to be an idiot to even drive a car you had ever been anywhere near.

I don't think piston-to-plug contact is possible. If you think about it, the plug is always where the plug is ... if the piston could touch it, it would touch it.

Unless of course your piston has gained a WWI style german flying helmet attachment

Most common cause of zero-gap plugs is the tech fitting them drops it down the bore hole because the rubbery bit in their plug socket is not working. Plug falls out of tool, hits the bottom of the bore and pinches the gap. I tend to use a bit of rubber pipe to lower the plugs into the bore and thread them to avoid this problem, though it's a long time since I removed a spark plug, so probably can no longer find said bit of pipe

Cheers,
Robin

Wrong plugs sounds a possibility, but they'd all be closed if they were hitting the piston.


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robin wrote:Most common cause of zero-gap plugs is the tech fitting them drops it down the bore hole because the rubbery bit in their plug socket is not working.

Completely off topic, but I had the opposite issue last month when I changed plugs. The plug went in fine, no dropping, but the rubbery bit then stayed on the plug rather than in the socket

Took me 20 minutes with a wire coat hanger to get it back out

I didn't want to go overboard on detail, but that's why I use a bit of rubber tube pushed over the spark plug top contact (sort of 3mm internal diameter). You can then just yank that off once the plug is threaded and then use a rubber-free spark plug socket to tighten

robin wrote:I didn't want to go overboard on detail, but that's why I use a bit of rubber tube pushed over the spark plug top contact (sort of 3mm internal diameter). You can then just yank that off once the plug is threaded and then use a rubber-free spark plug socket to tighten

Also avoids cross-threading. Sure I read about doing that in an old workshop manual for that reason somewhere.

Shug wrote: Also avoids cross-threading. Sure I read about doing that in an old workshop manual for that reason somewhere.

I am old ...