Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 964 & 993 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
Join Date: Nov 2013
Location: Torquay , UK
Posts: 77
Garage
Spark plug advice.

Have just done a decent service on my 92 C4. One problem arose.
Number 4 cylinder lower spark plug will not come out. All others plugs came out easily and they looked healthy. Fitted about 11 k miles ago by independent specialist I am happy with during a clutch change. Engine ran fine.
Number 4 lower plug losened fairly easily but then comes to a complete stop after about 1/8 of a turn with more than normal loosening force. Have tried various penetrating oils and moving it back and forth with no further loosening. Have not tried with warm/hot engine. On all the cars owned I have not experiened a siezed or cross threaded plug. (Plan for now - re-tighten and get car back together to deal w this as a separate issue)
Any advice on cause and solution would be appriciated.

Old 04-13-2020, 01:16 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered
 
Join Date: Apr 2006
Location: Ellicott City, MD
Posts: 349
Hopefully the ‘independent specialist’ did not over torque or cross thread.
I had this happen during a recent plug change on a friend’s 993 (exhaust bank). Unthreading it was difficult enough that I purchased a proper M14x1.25 spark plug thread chaser to clean the threads. The new plug went in smoothly after that.
It would be nice if you could pull the intake plug and somehow get penetrating oil to the stuck plug’s threads...






Andreas
__________________
1995 993 Coupe, Polar Silver / Black
2014 Audi A4, Monsoon Gray / Black
2002 Toyota 4Runner, Dorado Gold
2001 Toyota 4Runner, Dorado Gold, 463,XXX 1-owner miles

Last edited by AOW162435; 04-14-2020 at 06:18 AM..
Old 04-14-2020, 06:13 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
Join Date: Nov 2000
Location: TN
Posts: 149
I would back it out as far as you feel comfortable and soak it with Seafoam Deep Creep, then turn it in, and do that a couple times a day over the course of a few days. Deep Creep is the best penetrating fluid I've found and doesn't harm paint.

The next best penetrating fluid (in my experience), and has worked best for me in some cases is 1 part acetone and 1 part ATF, and it works very well but acetone will take paint off so be careful. It's a little tricky getting this on a 964 spark plug though.

Whenever you put new plugs in, put a healthy smear of milk of magnesia on the threads, it's a good anti seize without the hassle
__________________
Iron Hill Restorations
Home of the 914 Umbrella Cover
Custom engine harness for your 914-6 conversion
'91 964 Targa guards red, cashmere
several 914's and loads of parts
Old 04-21-2020, 03:22 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered
 
p911dad's Avatar
 
Join Date: Dec 2004
Location: Charlotte, NC
Posts: 1,649
Garage
There is also what I call the null alternative - that is, leave it in place for now. It only has 11,000 miles on it, so it's good to go for quite a while. Our old 84' Carrera had the same problem, # 3 plug would turn a small bit, maybe a 1/4 turn. I tried everything, nothing worked. So not wanting to damage the engine through a ham-handed effort I eventually gave up and left it alone. Years later a mechanic friend got it out during a routine plug change using a heat gun and Kroil penetrant. That's no endorsement of that method, it worked for him. After that I start putting a little dot of a copper based thread anti-seize paste. Good luck.
Old 04-21-2020, 05:15 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Nov 2011
Location: Usa
Posts: 622
Garage
Let the oil soak overnight and tighten the plug . Warm car up and it will come out when hot! Good luck
Old 04-23-2020, 06:10 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered
 
Join Date: Nov 2013
Location: Torquay , UK
Posts: 77
Garage
Thanks for the advice. Present status: car back on the road. Before that I soaked the plug a couple of times w ATF/aceton using a singel use plastic syringe with a plastic tube extension from a spray can. I will put a few heat cycles through it by driving it for a couple of weeks and have another feel. The advice not to rush a fix is quit valid. 11k miles on the plug gives it plenty of time for good service and it being a twin spark engine the offending cylinder has one brand new plug. Do more good than harm.
This will simply have to be a separate project. The initial plan of fitting a 100 cell cat and fix various anoying oil leaks has gone well, car now passes the Newspaper under the engine over night test.

Old 04-27-2020, 06:56 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 06:51 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2020 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.