V8 cylinder identification

[Truggy]

AFTERNOON!

2003 XKR - 4.2 supercharged V8

A cylinder went wonky! Got it diagnosed as "cylinder 4 misfiring". So I want to change the coil/plug/whatever it is. Just need some help identifying cylinder 4.

Access on one side is nice and easy, just a cover - see photo. The other side... I guess all the air filter is coming out.

Go on, tell me it's the easy side pls?

[Astromorg]

Your lucky day!
1, 3, 5, 7 on the RHS, No 1 at the front.
2, 4, 6, 8 on the LHS, No 2 at the front

[Truggy]

Your lucky day!

...except for the 90quid parking fine

Thank you very much

[Truggy]

That's looks like oil to me? Watery oil? New gasket I guess.

Whipped out number 2 and that was fine.

Probably time it went to a proper mechanic, if anyone has any recommendations in East Lancashire?

[Truggy]

I'm gunna try changing the spark plug and see what happens

[Astromorg]

That's probably no more than a leaking spark plug boss gasket. In the 4.2 engine there is one per plug and, of course a cam cover seal that would also need to be renewed with all 8 plug seals. Fairly straightforward job for an average home mechanic.

[mike020150]

It's probably worth mentioning that Jaguar altered the way it referred to the cylinder numbering for the 4.2 litre cars. Previously, the V8 in 4.0 litre cars was described as below:

Front of Engine
Bank 1 — Bank 2
Firing Order:
(Bank) - Cylinder
(1)-1, (2)-1, (1)-4, (1)-2, (2)-2, (1)-3, (2)-3, (2)-4.

Under some circumstances, this change of nomenclature can cause confusion. Mike.

[Truggy]

I'll end up changing all the spark plugs. What's a good brand? I work in the appliance industry, so I like ze German stuff, mainly Siemens.

[mike020150]

Whatever brand you choose, beware of fakes! Apparently, there are a lot of them available online so the best advice is to buy from a reputable source. Mike.

[Truggy]

I got 8 brand new Bosch. Replaced cylinder 4. Still the same!

Or does it need the fault clearing with the little machine thingy?

[mike020150]

If the plug were at fault, the misfire would simply disappear when the plug was replaced. Did you replace the coil pack too? If you didn't, one little trick which can work to cure some misfires is to stretch the connector spring on the coil pack to make a better connection before refitting it to the plug. For some reason, Jaguar coil packs seem prone to this issue. Mike.

[Truggy]

My mechanic just said coil pack!
He said oil ruins them. I'll get one ordered.

[Astromorg]

So he is going to fix the oil leak before fitting the new coil pack, isn't he?

[Truggy]

I'm gunna get it running so I can drive it to a good mechanic, that can do a full engine rebuild

[Truggy]

It was the coil pack

So... I'm looking for someone to do an engine restoration on it, in the North West... if anyone has any recommendations?

Off topic. But it need the gear box re-oiling too. Do we have a list of trusted mechanics anywhere on the forum?