plug gone down??

[d6dph]

Need some advice please.

The car has had a missfire for some time now, and tonight i think i have sussed it but would like someone with some brains to shed some light please.

is it possible that a plug core has cracked and when the car is cold, the crack is open. when warm the core expands and creates a solid core?

or am i really stupid!

thanks Dave

[d6dph]

anybody?

[Andy_magic]

I've seen it on bikes before.

Whats up with your car, does it miss when cold then sort itself when warmed up??

Check the plugs then do a compression test when cold and hot to be sure.

[Brianmoooore]

Sounds unlikely, but try a new plug anyway.

[d6dph]

thats exactly what it does.

i let the car warm for about 5 minutes before it turns a wheel, then i use the throttle it kinda sounds like a soft cut limiter. park up for 10 minutes then it is fine??

[Andy_magic]

I would start by finding out which cylinder is missing.

Get yourself a good pair of insulated pliers and nick some marigolds from somewhere and then pull each plug lead in turn, when you pull one and the engine note doesn't change you've found the offending cylinder.

Take the plug out and have a look at it, if you can't read plugs post a photo of it.

Try the plug out of the engine and see if it sparks, if it is obviously knackered change them, it could be something as simple as dodgy plug or lead.

The next step is to do a compression test.

hope that helps

[d6dph]

thanks for your help guys. change the plugs this morning and the miss has gone! shes back on form.

Thanks again Dave

[Andy_magic]

Sorted!