|
Author
|
Topic: Spark Plug keeps getting pushed to no gap
|
MRGT500
¯
Member # 8657
|
posted
 
 
Wussup guys. I got a 98 GT manual trans. 2 year old Remanufactured Motor. So i have had this problem for a couple weeks now. After pushing my car to about 4500 RPMs, the car will die or want to die unless you give it gas and keep the RPMs higher than idle. The car then has a misfire on cylinder 3. I pull the plug to find that tip has been pushed up against the center leaving no gap. I replaced the plug, and the same thing happened 2 weeks later at about the same power range of 4500 RPMs in 3rd gear. It was the same cylinder #3. Obviously the plug is being pushed in. I have heard from a muscle car mechanic that you can buy washer/spacer type things so that the spark plug can sit a little higher. I thought about trying those, but i want to know if i have a more SERIOUS problem? Any thoughtful brainstorming is greatly appreciated from the community.
--------------------
1965 6-cyl Convertible Blue (original)
1998 GT 5-Speed Black Stalker Kit
2013 GT 6-speed Black (Crashed/RIP)
Posts: 96 | From: Concord | Registered: Sep 2008
| :
|
|
Adam5.0
¯
Member # 6995
|
posted
Are you sure you have correct plugs in there?
--------------------
want something old and japanese
Posts: 1609 | From: Brentwood | Registered: Aug 2006
| :
|
|
MRGT500
¯
Member # 8657
|
posted
Yes. Its definetly the right plug.
--------------------
1965 6-cyl Convertible Blue (original)
1998 GT 5-Speed Black Stalker Kit
2013 GT 6-speed Black (Crashed/RIP)
Posts: 96 | From: Concord | Registered: Sep 2008
| :
|
|
LXjames
¯
Member # 10791
|
posted
Detonation. Heard this happens a lot when you use poor fuels
--------------------
On Point Motorsport prez.
King Lx
Posts: 4761 | From: Pittsburg CA | Registered: Mar 2011
| :
|
|
SteveL
¯
Member # 1241
|
posted
One of those scopes would help if you can borrow one. Pull the plug and look at the top of the piston. If there's a mark on the piston top, it's mechanical. No mark and it could be detonation.
Posts: 578 | From: San Jose, CA | Registered: May 2002
| :
|
|
MRGT500
¯
Member # 8657
|
posted
Great thanks guys. Im gonna borrow a scope and take a closer look. If its just detonation then i will replace some fuel components and get my timing readjusted. Any ideas on what my timing should be set to?
--------------------
1965 6-cyl Convertible Blue (original)
1998 GT 5-Speed Black Stalker Kit
2013 GT 6-speed Black (Crashed/RIP)
Posts: 96 | From: Concord | Registered: Sep 2008
| :
|
|
LXjames
¯
Member # 10791
|
posted
Stock is 10 degrees advanced
--------------------
On Point Motorsport prez.
King Lx
Posts: 4761 | From: Pittsburg CA | Registered: Mar 2011
| :
|
|
Brokn Nx
¯
Member # 8526
|
posted
I had this happen when I first swapped a new motor in a 98 GT. It actually broke the ceramic plug electrode on one of the plugs. When I first fired up the car it ran poorly and had a harsh knocking sound at idle. After awhile the sound went away and the motor ran much better but the check engine light said I had a misfire in one of the cylinders. I pulled all the plugs and found damage to 1,5, 4 and 8 plugs. After replacing all the plugs its been fine and hasn't had any problems in about 3k miles. Never did figure out why it happened, but since it seems fine now I chalked it up to low oil or fuel pressure at startup.
--------------------
85-0001 Saleen Mustang
88-362 Saleen Notch
85-090 Saleen Hatch
67 Stang Coupe
Posts: 333 | From: Santa Maria, CA | Registered: Jul 2008
| :
|
|
BIGBALLFACTOR
¯
Member # 7277
|
posted
good luc set your timing on your 98 gt.an if want some to look at that knows what there doing pm
Posts: 6908 | From: okc | Registered: Dec 2006
| :
|
|
Duncan Motors
¯
Member # 7045
|
posted
lol what he said is u cant set your timing on that car lol. crank and cam triggers dont move and if u want to trust him to work on your car, pm him.
the plug could be carbon build up, could be a loose rod coming up, i never heard of detonation doing that before. get a boroscope and see if it is hitting your piston. like said earlier above i think is your best bet.
Posts: 6310 | From: Vallejo | Registered: Sep 2006
| :
|
|
SLOWSN95
¯
Member # 8269
|
posted
There is no distributor on a 98 ![[Confused]](confused.gif)
--------------------
94' GT
347 Stroker
MM Suspended
2003 SB SVT Lightning
Pullied and Lowered
89'Hatch-SOLD
Posts: 2214 | From: 510/east bay | Registered: Mar 2008
| :
|
|
MRGT500
¯
Member # 8657
|
posted
So what if it is the piston hitting the plug?? Wat are my options? Do i have to pull the motor
--------------------
1965 6-cyl Convertible Blue (original)
1998 GT 5-Speed Black Stalker Kit
2013 GT 6-speed Black (Crashed/RIP)
Posts: 96 | From: Concord | Registered: Sep 2008
| :
|
|
JohnB
Tech Moderator
Member # 969
|
posted
You have internal damage of some sort. Plug gaps do not close due to detonation, they close because either the piston is coming apart...the piston/rod assembly is traveling farther than it should (rod bearing or wrist pin is shot)...or combo of the two.
As stated, the timing isn't adjustable unless you've had major engine and computer mods done.
--------------------
1965 Shelby Cobra
1993 Cobra
2012 F150 Raptor
2020 GT500
Posts: 6523 | From: Orlando FL/Redding CA | Registered: Mar 2002
| :
|
|
BIGBALLFACTOR
¯
Member # 7277
|
posted
has the been any spark plug insterts installed in the heads?
Posts: 6908 | From: okc | Registered: Dec 2006
| :
|
|
Ricks Hot Rod Lincoln
¯
Member # 7637
|
posted
Any luck?
You said it was a rebuild. The rebuilder may not have done a good job...
The spark plug shims are a bandaid fix, But they will get you by for a while. Do you have any old spark plugs to compare the ones that are in the engine right now? it is possible they were mis-labeled at the factory. Or you can look for a shorter length plug. Check out Plug #11
http://autolite.com/sites/default/a/uploads/en/plugtips.pdf
Any warranty? It is possible that the pistons are rocking in their bores so much they are coming up and hitting the plug just enough. Do you have any piston slapping sound? Has your oil pressure dropped lower than it used to be before the plug/s went bad?
I don't buy the; Detonation is causing plugs to close up theory.
--------------------
Son, Ya gonna drive me to drinkin if ya don't stop driving that Hot--Rod--Lincoln.
Posts: 46 | From: Sacramento, CA | Registered: May 2007
| :
|
|
|
|
MRGT500
¯
Member # 8657
|
posted
I still havent figured it out. Im pretty sure i still have the problem but i havent blown any plugs since that last time. Obviously i still have a problem but i have been choosing to ignore it and just not race. The car runs fine right now since i havent put it under any racing stress. My oil pressure is normal. No check engine light. I dont feel like the car is making any noise out of the ordinary except for idles kinda funny sometimes. Probably just need to replace my idle air control valve or whatever its called. I was talking to a few ford mechanics and they mentioned that ford 4.6 has a common problem with blowing spark plugs because of something to do with the spark plug threads. Does this sounds familiar to anyone?
--------------------
1965 6-cyl Convertible Blue (original)
1998 GT 5-Speed Black Stalker Kit
2013 GT 6-speed Black (Crashed/RIP)
Posts: 96 | From: Concord | Registered: Sep 2008
| :
|
|
MRGT500
¯
Member # 8657
|
posted
Also about the engine... I bought it as a remanufactured engine straight from detroit. The engine is stamped remanufactured in 2010. As far as the spark plugs, i am using NGK iridium from my local auto parts store.
--------------------
1965 6-cyl Convertible Blue (original)
1998 GT 5-Speed Black Stalker Kit
2013 GT 6-speed Black (Crashed/RIP)
Posts: 96 | From: Concord | Registered: Sep 2008
| :
|
|
Ricks Hot Rod Lincoln
¯
Member # 7637
|
posted
The blowing plugs out problem is related to the threads failing in the cylinder heads due to Ford's bad machining/castings... It is different then what your problem is.
Go buy 1 Motorcraft/Autolite/Champion plug for your car and pull one of your plugs out and compare them and check the plug length, threads, tip length, ETC... (Check out the links from Autolite)
On a side note, do you use anti-seize compound on the threads on your plugs?
--------------------
Son, Ya gonna drive me to drinkin if ya don't stop driving that Hot--Rod--Lincoln.
Posts: 46 | From: Sacramento, CA | Registered: May 2007
| :
|
|
MRGT500
¯
Member # 8657
|
posted
Im planning on doing a head swap after the winter. I want to convert to trickflow twisted wedge heads. Will this solve my problem? Will the bottom end of my engine be negatively affected by my current problem?
--------------------
1965 6-cyl Convertible Blue (original)
1998 GT 5-Speed Black Stalker Kit
2013 GT 6-speed Black (Crashed/RIP)
Posts: 96 | From: Concord | Registered: Sep 2008
| :
|
|
Greasy
¯
Member # 5258
|
posted
quote:
Originally posted by 98 Black GT Concord:
Im planning on doing a head swap after the winter. I want to convert to trickflow twisted wedge heads. Will this solve my problem? Will the bottom end of my engine be negatively affected by my current problem?
I'd fix the issue at hand before doing ANY modifications to it. If your piston is hitting the plug a new set of heads will not fix this.
--------------------
'93 Cobra-Coyote Powered
'03 DSG Cobra
'13 Dodge Cummins
'14 Rubicon X
Posts: 3272 | From: North Dallas | Registered: Jan 2005
| :
|
|
MRGT500
¯
Member # 8657
|
posted
Ok so do i need to pull the engine out and look? If its the piston then i need a rebuild right? How does this happen? My engine is 2 years old.
--------------------
1965 6-cyl Convertible Blue (original)
1998 GT 5-Speed Black Stalker Kit
2013 GT 6-speed Black (Crashed/RIP)
Posts: 96 | From: Concord | Registered: Sep 2008
| :
|
|
JohnB
Tech Moderator
Member # 969
|
posted
How does it happen? Poor rebuild, abuse, etc. I don't doubt detonation has caused damage to a piston crown and that's what is causing the damage to the plug. Have the cylinder scoped, it's alot cheaper AND easier than pulling the head.
--------------------
1965 Shelby Cobra
1993 Cobra
2012 F150 Raptor
2020 GT500
Posts: 6523 | From: Orlando FL/Redding CA | Registered: Mar 2002
| :
|
|
Ricks Hot Rod Lincoln
¯
Member # 7637
|
posted
First thing in to compare spark plugs per my previous post. this will be the cheapest starting point.
--------------------
Son, Ya gonna drive me to drinkin if ya don't stop driving that Hot--Rod--Lincoln.
Posts: 46 | From: Sacramento, CA | Registered: May 2007
| :
|
|
Email this post to someone!
Printer friendly view of this Ford topic
