Residue Oil when Replacing Spark Plugs - Any Ideas?

Tony · 05-10-2003, 09:38 AM

Dudes, Noticed when I was changing spark plugs (from the standard Denso's to 6 lovely NGK Iridium IX's - they make a noticeable difference I have to add) that some of the old ones had a moderate layer of dark (does that mean old?) oil coating the threads. The tips of the plugs were clean, dry and grey however. I also noticed that a thin layer of what seems like 'fresh' oil lined the lower edges of the spark plug remover (where it brushes against the side) after I'd extracted it.

I expect this means that the rocker cover gaskets may need replacing? Am I on the right track with this one?

Cosmo Dude · 05-10-2003, 04:28 PM

I think you may be right. First I'd remove the valve covers and clean up the old oil and monitor the situation for a few thousand km before spending the $$$ on new gaskets.

I recently replaced my valve cover seal and distributor 'O' ring and was over $60 in parts.
I have the BA 1.8

Rod

Tony · 05-10-2003, 04:45 PM

$60 in parts? Was that through Mazda?

Tony · 05-10-2003, 07:29 PM

Oh - another quick question. Will it hurt (cause any damage) if I don't have the gaskets replaced too soon? Finances are a bit stretched at the mo.

Also, what are the symptoms of a drop in compression?

BigMal · 07-10-2003, 10:28 AM

Lack of performance !!! Both from the fact that the energy from the combustion
is not forcing the piston down but going around and past the rings and also from
the pressure buildup in the sump that rises to the head and that air contains oil and
then goes out the breather at the corner of rocker cover and into the air intake
contaminating the airflow into the chamber.

Regards

Mal

Tony · 07-10-2003, 04:07 PM

Thanks heaps for that - performance is fine. I was just curious being as I'm a novice at all of this.

Cosmo Dude · 07-10-2003, 09:33 PM

Best indication of a lack of compression would be a compression test

Take it one step at a time, clean the plugs and their holes. Oil in all of them makes me think that there was human intervention. Gasket failure would hit 1 of 6 not all at once.
Why would someone pour oil into the plug holes? Your guess is as good as mine :shock: A good clean costs nothing but could potentionaly show the problem.

Rod

05-10-2003, 09:38 AM	#1
Tony Junior Member Join Date: May 2003 Location: Perth Posts: 54	Residue Oil when Replacing Spark Plugs - Any Ideas? Dudes, Noticed when I was changing spark plugs (from the standard Denso's to 6 lovely NGK Iridium IX's - they make a noticeable difference I have to add) that some of the old ones had a moderate layer of dark (does that mean old?) oil coating the threads. The tips of the plugs were clean, dry and grey however. I also noticed that a thin layer of what seems like 'fresh' oil lined the lower edges of the spark plug remover (where it brushes against the side) after I'd extracted it. I expect this means that the rocker cover gaskets may need replacing? Am I on the right track with this one? __________________ BA Astina Hatch V6 Classic Red

05-10-2003, 04:28 PM	#2
Cosmo Dude コスモ Join Date: Dec 2002 Location: Location: Vic Car: Mazda '95 Astina I4, '86 B2K and '10 3 MZR-CD Posts: 7,888 View Photos By: Cosmo Dude	I think you may be right. First I'd remove the valve covers and clean up the old oil and monitor the situation for a few thousand km before spending the $$$ on new gaskets. I recently replaced my valve cover seal and distributor 'O' ring and was over $60 in parts. I have the BA 1.8 Rod __________________ My 'stina Hatch

05-10-2003, 04:45 PM	#3
Tony Junior Member Join Date: May 2003 Location: Perth Posts: 54	$60 in parts? Was that through Mazda? __________________ BA Astina Hatch V6 Classic Red

05-10-2003, 07:29 PM	#4
Tony Junior Member Join Date: May 2003 Location: Perth Posts: 54	Oh - another quick question. Will it hurt (cause any damage) if I don't have the gaskets replaced too soon? Finances are a bit stretched at the mo. Also, what are the symptoms of a drop in compression? __________________ BA Astina Hatch V6 Classic Red

07-10-2003, 10:28 AM	#5
BigMal 1ST BA TURBO MEMBER Join Date: Mar 2002 Location: Sydney Car: BA Astina Turbo Posts: 4,195 View Photos By: BigMal	Lack of performance !!! Both from the fact that the energy from the combustion is not forcing the piston down but going around and past the rings and also from the pressure buildup in the sump that rises to the head and that air contains oil and then goes out the breather at the corner of rocker cover and into the air intake contaminating the airflow into the chamber. Regards Mal __________________ If you want wind in your hair add a Hairdryer !!!

07-10-2003, 04:07 PM	#6
Tony Junior Member Join Date: May 2003 Location: Perth Posts: 54	Thanks heaps for that - performance is fine. I was just curious being as I'm a novice at all of this. __________________ BA Astina Hatch V6 Classic Red

07-10-2003, 09:33 PM	#7
Cosmo Dude コスモ Join Date: Dec 2002 Location: Location: Vic Car: Mazda '95 Astina I4, '86 B2K and '10 3 MZR-CD Posts: 7,888 View Photos By: Cosmo Dude	Best indication of a lack of compression would be a compression test Take it one step at a time, clean the plugs and their holes. Oil in all of them makes me think that there was human intervention. Gasket failure would hit 1 of 6 not all at once. Why would someone pour oil into the plug holes? Your guess is as good as mine :shock: A good clean costs nothing but could potentionaly show the problem. Rod __________________ My 'stina Hatch

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Funny things you've been sent lately...	Rupewrecht	Off Topic	2682	16-05-2016 06:31 PM
NGK Iridium Spark Plugs on v6 - help --> maybe just a simple answer	Noble323	Performance & General Maintenance	4	07-09-2005 04:17 AM
GB: [QLD] NGK Iridium spark plugs - Another Twiggy Special!	twilightprotege	For Sale/Wanted	174	05-02-2005 09:33 PM
Oil in spark plugs	sirex	Performance & General Maintenance	3	10-10-2004 11:35 PM
FS : NGK Iridium Spark Plugs	twilightprotege	For Sale/Wanted	17	14-09-2004 07:15 AM