Ford Focus II (2004 - 2007) - 05 1.6 Spark plug gap

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Sun 9 Nov 2008 10:25
05 1.6 Spark plug gap - Ian Roberts
I've just replaced the spark plugs in my car.

My local motor factors supplied me with NGK plugs gapped at 1.0mm, which seems to agree with every website I have checked that has a facility to look up the correct spark plugs for my car.

However, the plugs I removed were gapped at 1.3mm and having spoken to a number of people this seems to be what Ford usually fit.

The car seems to run fine with both plug gaps.

Can anyone which are correct and why I am seeing a discrepancy? Also what would be the advantage / disadvantage of running with too small / large a gap?

Edited by Pugugly on 09/11/2008 at 10:54

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Sun 9 Nov 2008 11:34
05 1.6 Spark plug gap - mfarrow
Ford certainly used to have a little sticker on the front of the engine bay telling you this information. Does yours?
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Sun 9 Nov 2008 13:57
05 1.6 Spark plug gap - yorkiebar
Plugs for this car should come pre gapped.

Stick with the gap recommended by the plug manufacturer. Are they the right plugs?
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Sun 9 Nov 2008 16:03
05 1.6 Spark plug gap - Ian Roberts
Ford certainly used to have a little sticker on the front of the engine bay
telling you this information. Does yours?


I'll have to check on that.
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Sun 9 Nov 2008 15:33
05 1.6 Spark plug gap - Screwloose

NGK TR5A-10 were specified. Those come gapped at 1.0mm. The recommended gap is 1.3?
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Sun 9 Nov 2008 15:58
05 1.6 Spark plug gap - kithmo
IIRC larger plug gaps have something to do with reducing emissions.
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Sun 9 Nov 2008 16:01
05 1.6 Spark plug gap - yorkiebar
Recommended by who SW ?

The info I have is 1.0 mm, as is Denso T16VR-U10.

In both ngk and denso, the last part of the plug number (10) is equal to the gap.

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Sun 9 Nov 2008 16:06
05 1.6 Spark plug gap - Ian Roberts
Recommended by who SW ?
The info I have is 1.0 mm as is Denso T16VR-U10.
In both ngk and denso the last part of the plug number (10) is equal
to the gap.


Everything is pointing at 1.0mm being the recommended gap.

I'm just baffled as to why the originals are 1.3mm. Maybe I'm not going to get an answer :D
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Sun 9 Nov 2008 16:46
05 1.6 Spark plug gap - Screwloose
yorkie

As you say; the number gives the factory-set gap; that was the reason for the question mark - AD say 1.3 for all makes?
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Sun 9 Nov 2008 16:04
05 1.6 Spark plug gap - Ian Roberts
NGK TR5A-10 were specified. Those come gapped at 1.0mm. The recommended gap is 1.3?


It is the TR5A-10 that I have just fitted. The ones I removed were gapped at 1.3mm and from what I've gathered Ford recommend 1.3mm
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Sun 9 Nov 2008 16:19
05 1.6 Spark plug gap - bathtub tom
Could the gap have opened up in use?

They certainly used to, but with modern materials 0.3mm seems an awful lot.
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Sun 9 Nov 2008 21:18
05 1.6 Spark plug gap - Galaxy
I can only comment on the Mondeo engine but assume the same applies to the Focus engine, too, since they are essentially the same engine.

Ford originally specified a plug gap of 1.3mm for the Zetec engine. However, this gap was found in practice to cause problems with coil pack and lead failures. As a result, Ford issued a TSB on this and reduced the gap from 1.3mm to 1.0mm, which appears to have solved the problems which were occurring.

I guess it's the same for the Zetec engine in the Focus. If you buy the correct plugs then they are already set to be the correct gap. Indeed, I believe the advice given is that you shouldn't adjust them.

Edited by Galaxy on 09/11/2008 at 21:20

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Sun 9 Nov 2008 21:27
05 1.6 Spark plug gap - Dynamic Dave
Are these single or multi electrode plugs. If multi electrode they shouldn't be adjusted as it would be near on impossible to set exactly the same gap size on each of the plugs.
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Mon 10 Nov 2008 18:36
05 1.6 Spark plug gap - Ian Roberts
Snipquote
Ford originally specified a plug gap of 1.3mm for the Zetec engine. However this gap
was found in practice to cause problems with coil pack and lead failures. As a
result Ford issued a TSB on this and reduced the gap from 1.3mm to 1.0mm
which appears to have solved the problems which were occurring.



That certainly would explain the discrepancy!

Edited by Dynamic Dave on 10/11/2008 at 18:58

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Tue 11 Nov 2008 09:49
05 1.6 Spark plug gap - 547HEW
The 1.3mm gap was introduced to improve idle stability. However, I doubt if you will notice any difference when using 1.00mm gap.
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Sat 14 Nov 2009 16:23
05 1.6 Spark plug gap - Junglejames
Staying slightly on the same subject, but on an 06 1.6 focus, has anybody any idea why the car isnt liking these NGK spark plugs everyone else is on about?
Recently replaced my spark plugs with these NGK's, gap left as it was- 1.0mm as suggested by Haynes. Engine seems to run fine, but the Engine warning light stays on, and wont go out. Also it seems to be slightly lacking power wise. Not by much, jut a little bit.
Changed the spark plugs back to the old ones, and everything is fine.
Anyone any idea what the problem is?
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Thu 20 Oct 2011 15:12
05 1.6 Spark plug gap - Klout

I have just set about changing the plugs on my 1.6 Zetec because of poor idling & cold starting.

I found that the connector on the coil pack for ignition lead number 4 lead was totally worn and charred black. I am amazed the car ran at all. Perhaps check your coil pack for signs of wear?

I bought a new coil pack on Ebay, it seems to run fine so far.

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