Spark plug bent.

[JackJones]

So... I had a service about 1 week ago. Changed the spark plugs in the process just to be a good Audi owner and keep my car maintained. I have the audi s3 (8p) 57 plate.

Today after not much use of the car. I started up the car to notice the idle was off (unstable), a mile down the road and my emmisions/engine management light came on.

Got home a little upset and started surfing the forums to find a possible cause. A friend has a diagnostic machine so I had him come round and plug it in to find I have a miss firing cylinder. After going through a few checks I pulled out the spark plug on cylinder 4 and guess what... The spark plug is bent and touching where the spark comes from.

After bending back (short term fix until I get a new plug tomorrow..) the car is running fine. My only questions now are..

1# maybe the piston has hit the spark plug causing it to bend the plug ?

2# If this is the case what sort of work am I looking at ?

3# Should I be worried ?

or am I good to go and just totally paranoid..

Car has done 48k

 

[pluves1]

When you replaced a week ago did you set the gaps?
Do you have a pic of the 'bent' spark plug and if not what do you mean by bent? Was the gap just closed or something more serious? If it was something more serious then I would check the following

1. You definitely have the correct spark plugs. Incorrect one might protrude too far into the combustion chamber.
2. Something has found its way into the combustion chamber and is too large to go out through the exhaust valve. Valve could have broken.
3. Rod bearing is letting go and therefore piston has contacted the plug.

After checking spark plugs are correct ones I would be getting a compression test on cylinder 4 done pretty sharpish before I put a new spark plug back in.

 

[JackJones]

I forgot to mention that I didn't set the plugs as my mate is a mechanic and is the one who done the service for me.

I don't have a pic but I have already bent it back already so I can't now take the pic.

And by bent I mean literally bent and touching the point where the spark is created.. Like in this image I found through google ( http://www.thehulltruth.com/attachm...-suzuki-d175-smashed-spark-plugs-imag0192.jpg )

I'll have a compression test done ASAP. Thanks for the info.

 

[SmithyAG]

Dropping a spark plug can close the gap too, although would have expected it to show up sooner than a week.

 

[JackJones]

I hadn't drive it about much, I was thinking this. I'll still do a compression test ASAP (hopefully tomorrow)

Spoke to my mate who did the service he thinks it could of been damaged before he put it in... Doh! But I'll have to wait and see. Hoping there isn't anything in the cylinder (FML if there is)

 

[JackJones]

Driven*

 

[Broken Byzan]

If it was touching at install it would have ran on 3 on first start. Suprised it's not been spotted by either of you

 

[JackJones]

Hmm so you think it's something more sinister ? I'll be taking it tomorrow to check the cylinder and hopefully get a compression test done too. Thanks for the input.

 

[Broken Byzan]

Well no. But if it was started after service I'd expect even a novice to notice. However if hardly used since its possible. A quick compression check should put your mind at rest

 

[JackJones]

I have done a compression test on my jet ski I'm sure it's kinda simple just don't know what I should be expecting in terms of pressure readings and ratios. Any idea ? What sort of readings I should be expecting to see.

 

[fangio]

If there was damage such as a broken valve, you'd certainly know about it!!!

If the plugs are the correct ones, it was probably closed up before being fitted.

 

[JackJones]

That's exactly what my mate said, I'll still do the compression test tomorrow to be safe. Was hoping to get hold of an endoscope to look into the cylinder. Can't find one locally to pick up.

 

[Marshy]

Wouldn't waste my time and effort on doing a compression test.
Obviously the plug has been damaged on install just not sure why it wasn't picked up right away.
If anything had touched it you'd know about it.
Put a new plug in and that's it sorted.
Its a few inch drop when installing the plugs and obviously a magnet wasn't used.

 

[JackJones]

Going to pick a plug up today. Thanks for your input. Puts my mind at ease

 

[fangio]

Why another new plug? You set the gap by bending the electrode that was touching the centre. That bent bit is just the earth.

Electricity comes down the centre and jumps the gap, creating the spark. Just as long as the gap's the same as the others.

Good post here:-

http://www.audi-sport.net/vb/a3-s3-...-recommendations-s3-8p-2-0t-oem-modified.html

 

[Marshy]

I said a new plug just incase there's any damage to the electrode. If there's a fracture or damage and it breaks it can do damage.
For the price of 1 x plug I'd be replacing it.

 

[JackJones]

Tbh I'v already replaced it anyway but I thank you all for the input. Each to their own etc.