Lotus Elan

Oil around spark plug

PostPost by: William2 » Fri Sep 07, 2018 8:09 am

On my engine I have noticed oil around number 1 plug that seems to come up through the plug threads. I don't want to tighten the plug too much and risk stripping the threads. Is this a common problem that happens when the threads get worn and oil weeps through? I can confirm that the oil is not coming from the cam cover gasket and I have even fitted a new spark plug. As an aside, I always apply a smear of Copperslip to the plug threads.
William2
Fourth Gear
Fourth Gear
 
Posts: 942
Joined: 20 Jan 2013
Location: West Sussex

PostPost by: Europatc » Fri Sep 07, 2018 10:41 am

Have you checked the washer on the plug? Not a lot to go wrong I know but always check the cheap options first
ImageImage
User avatar
Europatc
Third Gear
Third Gear
 
Posts: 391
Joined: 19 Aug 2010
Location: Hessle East Yorkshire

PostPost by: rgh0 » Sat Sep 08, 2018 12:15 am

Oily residue will come up the treads if the plug gasket is not sealing and leaking regardless of the thread condition it is the plug gasket seal that is critical.

The plug needs to be tightened correctly to achieve the needed compression on the plug gasket. This is normally indicated on the plug box as the amount of further tightening once the plug gasket is seated finger tight and equates typically to around 20 ft- lbs of torque (and 1/2 to 2/3 of a turn for the Elan Plugs for new plugs)

http://www.ngk-sparkplugs.jp/english/te ... index.html

Closely inspect the sealing surface on the head to ensure it is not damaged if your getting leakage past a correctly torqued spark plug. A crack in this surface could allow bypassing of the gasket.

I agree you should always use anti-seize ( i prefer Loctite Nickel anti-seize) to help prevent damage to the alloy threads in the head

cheers
Rohan
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7511
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: Donels » Sat Sep 08, 2018 8:23 am

Rohan,
Interested to see you recommend anti-seize compound. Do you reduce the torque setting to compensate? Typically with anti-seize there is usually a reduced torque required.

Dave
Elan +2
Elise mk 1
Donels
Third Gear
Third Gear
 
Posts: 322
Joined: 10 Sep 2016
Location: Tamworth

PostPost by: rgh0 » Sun Sep 09, 2018 12:50 am

Donels wrote:Rohan,
Interested to see you recommend anti-seize compound. Do you reduce the torque setting to compensate? Typically with anti-seize there is usually a reduced torque required.

Dave


Hi Dave
I find with a new plug and anti-seize on the threads around 20 ft lbs is required to get the 2/3 rd of a turn compression on the plug gasket. I use the same 20 ft lbs when reinstalling a used plug.

cheers
Rohan
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7511
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: William2 » Sun Sep 09, 2018 9:06 am

Thanks for your advice Rohan. As an aside, I guess a plug washer never seals as well as it does on the first compression seal.
William2
Fourth Gear
Fourth Gear
 
Posts: 942
Joined: 20 Jan 2013
Location: West Sussex

PostPost by: promotor » Sun Sep 09, 2018 9:16 am

I've had new spark plugs where the sealing gasket/ring has completely broken off the spark plug - this seems to be an indication of fake plugs as I've never seen that before until I bought spark plugs on line from an unverified source.

Check that the gasket/ring is still good.
User avatar
promotor
Fourth Gear
Fourth Gear
 
Posts: 528
Joined: 16 Mar 2012
Location: Derbyshire, U.K.

Total Online:

Users browsing this forum: No registered users and 15 guests