Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: SteveAvfc. on 09 May 2012, 17:20:59

Title: Spark plugs sooted.
Post by: SteveAvfc. on 09 May 2012, 17:20:59
Hi OOFers can some one shed light as to why my recently fitted VX spark plugs are looking sooted they have only been in for about two months. The car seems to run perfect for a few weeks then starts to play up poor acceleration hunting ect, have recently found breather pipes were cracked so replaced and all seemed well. Then started to run poor again had a look at the plugs and they are sooted at the bases, could this be the problem and if so what would be the best solution. Thanks in advance for your answers.Steve  :y :y :y
Title: Re: Spark plugs sooted.
Post by: feeutfo on 09 May 2012, 17:47:36
Do you mean soot on the electrode and insulation from poor combustion?

Or around the external section that sits in the plug well?
Title: Re: Spark plugs sooted.
Post by: SteveAvfc. on 09 May 2012, 18:24:56
Do you mean soot on the electrode and insulation from poor combustion?

Or around the external section that sits in the plug well?
The actual electrode tip looks ok-ish but they are sooted around the base and i would say up to three/four thread turns from the base. Externally they are clean. 


Title: Re: Spark plugs sooted.
Post by: RobG on 09 May 2012, 18:29:21
Plugs all tightened to 25Nm ???
Title: Re: Spark plugs sooted.
Post by: SteveAvfc. on 09 May 2012, 18:44:50
Plugs all tightened to 25Nm ???
They were done at the garage Rob so would hope so but who knows ?? Could it be running to rich? if so remedy's please they do look in a poor state for two months wear.
Title: Re: Spark plugs sooted.
Post by: RobG on 09 May 2012, 18:48:57
Normal cause of soot is loose plugs, have you checked for tightness. 25Nm will compress the "crush" washer but plugs have and do work loose
Title: Re: Spark plugs sooted.
Post by: SteveAvfc. on 09 May 2012, 18:52:44
Normal cause of soot is loose plugs, have you checked for tightness. 25Nm will compress the "crush" washer but plugs have and do work loose
Thanks Rob will look into it  :y :y
Title: Re: Spark plugs sooted.
Post by: feeutfo on 09 May 2012, 20:57:05
Plugs are coming loose by the sound of it. As Rob says, 25nm each. And as master says, then go over them again as they may well relax on the crush washers.
Title: Re: Spark plugs sooted.
Post by: Kevin Wood on 10 May 2012, 11:13:41
The condition of the plug is not a reliable indicator of how an engine's running, in reality. You might get a clean plug if the engine was cut immediately after being driven under load, but a few seconds of idling and the plug will cool and collect a layer of soot.

I would say the plugs are unlikely to be the problem but if they haven't been changed recently then it won't hurt to try some new ones.

They do have a habit of coming loose. The trick is to tighten them to 25Nm, leave them for a few minutes, then go round them again and double check.

So, on to the running problem. Any fault codes stored? Is it running poorly just at idle or under load? Throughout the whole rev range or just in one place?
Title: Re: Spark plugs sooted.
Post by: SteveAvfc. on 10 May 2012, 17:07:45
The condition of the plug is not a reliable indicator of how an engine's running, in reality. You might get a clean plug if the engine was cut immediately after being driven under load, but a few seconds of idling and the plug will cool and collect a layer of soot.

I would say the plugs are unlikely to be the problem but if they haven't been changed recently then it won't hurt to try some new ones.

They do have a habit of coming loose. The trick is to tighten them to 25Nm, leave them for a few minutes, then go round them again and double check.

So, on to the running problem. Any fault codes stored? Is it running poorly just at idle or under load? Throughout the whole rev range or just in one place?
The car seems to run worse during warm up, dose not seem to affect acceleration up through the box its becomes apparent when moving at lower speeds.
Title: Re: Spark plugs sooted.
Post by: RobG on 10 May 2012, 18:14:01
The condition of the plug is not a reliable indicator of how an engine's running, in reality. You might get a clean plug if the engine was cut immediately after being driven under load, but a few seconds of idling and the plug will cool and collect a layer of soot.

I would say the plugs are unlikely to be the problem but if they haven't been changed recently then it won't hurt to try some new ones.

They do have a habit of coming loose. The trick is to tighten them to 25Nm, leave them for a few minutes, then go round them again and double check.

So, on to the running problem. Any fault codes stored? Is it running poorly just at idle or under load? Throughout the whole rev range or just in one place?
The car seems to run worse during warm up, dose not seem to affect acceleration up through the box its becomes apparent when moving at lower speeds.
Title: Re: Spark plugs sooted.
Post by: JamesV6CDX on 10 May 2012, 19:04:12
The condition of the plug is not a reliable indicator of how an engine's running, in reality. You might get a clean plug if the engine was cut immediately after being driven under load, but a few seconds of idling and the plug will cool and collect a layer of soot.

I would say the plugs are unlikely to be the problem but if they haven't been changed recently then it won't hurt to try some new ones.

They do have a habit of coming loose. The trick is to tighten them to 25Nm, leave them for a few minutes, then go round them again and double check.

So, on to the running problem. Any fault codes stored? Is it running poorly just at idle or under load? Throughout the whole rev range or just in one place?
The car seems to run worse during warm up, dose not seem to affect acceleration up through the box its becomes apparent when moving at lower speeds.

If I get Claires car done on Saturday in good time I'd be happy to take a look...
Title: Re: Spark plugs sooted.
Post by: SteveAvfc. on 10 May 2012, 19:30:59
The condition of the plug is not a reliable indicator of how an engine's running, in reality. You might get a clean plug if the engine was cut immediately after being driven under load, but a few seconds of idling and the plug will cool and collect a layer of soot.

I would say the plugs are unlikely to be the problem but if they haven't been changed recently then it won't hurt to try some new ones.

They do have a habit of coming loose. The trick is to tighten them to 25Nm, leave them for a few minutes, then go round them again and double check.

So, on to the running problem. Any fault codes stored? Is it running poorly just at idle or under load? Throughout the whole rev range or just in one place?
The car seems to run worse during warm up, dose not seem to affect acceleration up through the box its becomes apparent when moving at lower speeds.

If I get Claires car done on Saturday in good time I'd be happy to take a look...
Thanks James for your offer will try tightening them first possibly tomorrow afternoon see how it goes. If she still plays up will make contact, your doing Claires car would that be down around here or is that more Gloucester way ??.  :y
Title: Re: Spark plugs sooted.
Post by: JamesV6CDX on 10 May 2012, 19:57:57
The condition of the plug is not a reliable indicator of how an engine's running, in reality. You might get a clean plug if the engine was cut immediately after being driven under load, but a few seconds of idling and the plug will cool and collect a layer of soot.

I would say the plugs are unlikely to be the problem but if they haven't been changed recently then it won't hurt to try some new ones.

They do have a habit of coming loose. The trick is to tighten them to 25Nm, leave them for a few minutes, then go round them again and double check.

So, on to the running problem. Any fault codes stored? Is it running poorly just at idle or under load? Throughout the whole rev range or just in one place?
The car seems to run worse during warm up, dose not seem to affect acceleration up through the box its becomes apparent when moving at lower speeds.

If I get Claires car done on Saturday in good time I'd be happy to take a look...
Thanks James for your offer will try tightening them first possibly tomorrow afternoon see how it goes. If she still plays up will make contact, your doing Claires car would that be down around here or is that more Gloucester way ??.  :y

It's actually the other direction... but, I'd happily keep going on the M5, on the way home, for the sake of a beer token to cover the LPG :y

Could run some diags, look at the live data and see if we can determine any issues :y
Title: Re: Spark plugs sooted.
Post by: SteveAvfc. on 11 May 2012, 15:39:34
The condition of the plug is not a reliable indicator of how an engine's running, in reality. You might get a clean plug if the engine was cut immediately after being driven under load, but a few seconds of idling and the plug will cool and collect a layer of soot.

I would say the plugs are unlikely to be the problem but if they haven't been changed recently then it won't hurt to try some new ones.

They do have a habit of coming loose. The trick is to tighten them to 25Nm, leave them for a few minutes, then go round them again and double check.

So, on to the running problem. Any fault codes stored? Is it running poorly just at idle or under load? Throughout the whole rev range or just in one place?
The car seems to run worse during warm up, dose not seem to affect acceleration up through the box its becomes apparent when moving at lower speeds.

If I get Claires car done on Saturday in good time I'd be happy to take a look...
Thanks James for your offer will try tightening them first possibly tomorrow afternoon see how it goes. If she still plays up will make contact, your doing Claires car would that be down around here or is that more Gloucester way ??.  :y

It's actually the other direction... but, I'd happily keep going on the M5, on the way home, for the sake of a beer token to cover the LPG :y

Could run some diags, look at the live data and see if we can determine any issues :y
Hi James have PM you Steve.
Title: Re: Spark plugs sooted.
Post by: JamesV6CDX on 11 May 2012, 15:42:07
Cheers mate. Providing I'm not too late back on Saturday I'll keep going and pop in. I'll make sure I let you know on the mobile :y

Title: Re: Spark plugs sooted.
Post by: SteveAvfc. on 11 May 2012, 15:43:14
Cheers mate. Providing I'm not too late back on Saturday I'll keep going and pop in. I'll make sure I let you know on the mobile :y
:y :y