Spinning Spark Plugs? - Alfa Romeo Forum
You are currently unregistered, register for more features.    
 
Thread Tools
(Post Link) post #1 of 22 Old 27-04-14 Thread Starter
Status: A GTV you say?
AO Member
 
Teuchter's Avatar
 
Join Date: Mar 2012
Location: United Kingdom
County: Highlands
Posts: 260

Member car:

99 GTV 3.0 V6

Help Spinning Spark Plugs?

Just spent the best part of today dismantling the engine intending to replace the spark plugs on my 2.5 V6 only to find when I got to the point of unscrewing them out (I tried No.1 and 4) neither would feel as though they were loosening at all and I didn't see the point of trying the others. My assumption is that an ape had over tightened them when they were last replaced and stripped the threads rendering my efforts useless, or have I missed something of do something different?

P.s. And yes I was turning them anti-clockwise.

Gavin

Bilstein B14 PSS Coil overs,
Eibach Front and Rear ARBs,
Novitec Front Spoiler,
WizardOvOz Unicorse Replica Cat-Back,
Performance Friction Pads,
Autolusso Braided Hoses,
BMC CDA.
Teuchter is offline  
Sponsored Links
Advertisement
 
rhett71
Status: - Update
Guest
 
Posts: n/a
The thread title suggests they spin but don't come out?
 
(Post Link) post #3 of 22 Old 27-04-14 Thread Starter
Status: A GTV you say?
AO Member
 
Teuchter's Avatar
 
Join Date: Mar 2012
Location: United Kingdom
County: Highlands
Posts: 260

Member car:

99 GTV 3.0 V6

Yeah pretty much, they rotate but the friction remains the same after two complete turns and don't budge.
Teuchter is offline  
Status: -
AO Member
 
Join Date: Apr 2010
Location: United Kingdom
County: Kent
Posts: 802
If they were stripped they would have blown out the head,are you using the correct size plug spanner ?

John
black cat is offline  
(Post Link) post #5 of 22 Old 28-04-14 Thread Starter
Status: A GTV you say?
AO Member
 
Teuchter's Avatar
 
Join Date: Mar 2012
Location: United Kingdom
County: Highlands
Posts: 260

Member car:

99 GTV 3.0 V6

Aye I think I am, I'm using a 10mm plug socket. I'll try again if I have time after work but this time I'll run the engine up to temp.
Teuchter is offline  
Status: V6 Inside
AO Silver Member
 
ransoman's Avatar
 
Join Date: Jan 2007
Location: United Kingdom
County: Aberdeenshire
Posts: 4,881
They are bigger than 10mm i think.

I am not sure what the universal plug size is, 16mm i think but 10 is definately too small.
ransoman is offline  
rxe
Status: Busso
AO Silver Member
 
Join Date: Apr 2012
Location: United Kingdom
County: Berkshire
Posts: 4,082
16mm for the narrow head NGKs. 21mm is the old fashioned "big" size. 10 mm plug sockets are normally for glow plugs.
rxe is offline  
(Post Link) post #8 of 22 Old 28-04-14 Thread Starter
Status: A GTV you say?
AO Member
 
Teuchter's Avatar
 
Join Date: Mar 2012
Location: United Kingdom
County: Highlands
Posts: 260

Member car:

99 GTV 3.0 V6

I don't know why but it states 10mm on the socket but it's a 16mm.
Teuchter is offline  
Status: 159 2.4 20007 plate 19,500 DPF/EGR by Adie (AHM)
AO Silver Member
 
Join Date: May 2009
Location: United Kingdom
County: Wiltshire
Posts: 2,322
An ISO 10mm threaded nut or bolt has a 16mm across flats (AF) measurements on the nut or bolt head.

The thread is 10mm but the plug across flats at the spanner section is 16mm.
kandlbarrett is offline  
Status: 159 2.4 20007 plate 19,500 DPF/EGR by Adie (AHM)
AO Silver Member
 
Join Date: May 2009
Location: United Kingdom
County: Wiltshire
Posts: 2,322
Plenty of tables on the net for ISO nut and bolt dimensions.

They can all be calculated for standard bolts though.

AF (across flats) = 1.6 x diameter
AC (across corners) = 1.8 x diameter.
Nut or both head thickness = 0.7 x diameter.
kandlbarrett is offline  
rhett71
Status: - Update
Guest
 
Posts: n/a
Quote:
Originally Posted by kandlbarrett View Post
An ISO 10mm threaded nut or bolt has a 16mm across flats (AF) measurements on the nut or bolt head.

The thread is 10mm but the plug across flats at the spanner section is 16mm.
I don't think he's talking about AF in millimetres?. I have noticed that if you are using a dedicated sparkplug socket the numbers are not the AF size they are for the plug thread and I believe they are imperial? Have a look at this http://www.ngksparkplugs.com/techinf...tnumberkey.pdf
 
Status: SOLD my 156!
AO Gold Member
 
gazza82's Avatar
 
Join Date: Jan 2003
Location: United Kingdom
County: Buckinghamshire
Posts: 9,061
The TS plugs fit a 10mm plug socket ... not sure about V6 plugs but likelyhood is the "nut" part is larger.

*** just checked and the PFR6B fitted to the V6 is a 16mm hex ... same as TS plugs ***

Gary

Last edited by gazza82; 29-04-14 at 13:04. Reason: added hex sizes
gazza82 is offline  
Status: -
AO Silver Member
 
seadart's Avatar
 
Join Date: Oct 2010
Location: United Kingdom
County: Hampshire
Posts: 2,197
All this goes back to ancient history when spanner sizes were the thread size .. Whitworth etc ..
when unified national threads came along. which was joint Brit/Yank.. in the interests of winning a war with only one set of spanners.. sorry wrenches.... for a Yank plane with a Brit engine etc..
spanner sizes were quoted as AF..size across nut flats.
Metric was the same
For some unfathomable reason plug spanners carried on being sized as the plug thread size.. sometimes??
just shove it on and see if it fits..

Last edited by seadart; 29-04-14 at 14:35.
seadart is offline  
Status: -
AO Gold Member
 
Join Date: Jul 2004
Location: United Kingdom
County: Derbyshire
Posts: 6,499
Quote:
Originally Posted by seadart View Post
All this goes back to ancient history when spanner sizes were the thread size .. Whitworth etc ..
Which was made more complicated during WWII. To save material the head sizes for BSW fasteners were changed to the same A/F dimensions as the equivalent BSF hexagon, so the markings on a spanner may not match the size of the thread.
Dave Brand is offline  
Status: SOLD my 156!
AO Gold Member
 
gazza82's Avatar
 
Join Date: Jan 2003
Location: United Kingdom
County: Buckinghamshire
Posts: 9,061
Complicated enough now ... the 10mm plug spanner I have fits both the large (14mm thread) and small (10mm thread) plugs in a TS engine ... both of which are listed on NGK site as 16mm hex ... the threads might be different sizes but the hex isn't ...

V6 plugs also showing as 16mm hex, with 14mm thread ... so a 10mm plug socket should fit.

Maybe the OP isn't pushing down hard enough and the rubber insert in the socket is stopping it from locating properly ...
gazza82 is offline  
Status: -
AO Silver Member
 
seadart's Avatar
 
Join Date: Oct 2010
Location: United Kingdom
County: Hampshire
Posts: 2,197
Quote:
Originally Posted by Dave Brand View Post
Which was made more complicated during WWII. To save material the head sizes for BSW fasteners were changed to the same A/F dimensions as the equivalent BSF hexagon, so the markings on a spanner may not match the size of the thread.
Ha Ha great..

It's a good job that we managed to win WWII, or we would all be driving around in BMW's, Honda's and Alfa's by now..
seadart is offline  
(Post Link) post #17 of 22 Old 29-04-14 Thread Starter
Status: A GTV you say?
AO Member
 
Teuchter's Avatar
 
Join Date: Mar 2012
Location: United Kingdom
County: Highlands
Posts: 260

Member car:

99 GTV 3.0 V6

I think I was going about it too gingerly and had another crack at them with Plusgas and a stronger will. They were stiff mainly because whoever done them last hadn't put any anti-seize on them so I got a bit scared at unscrewing 3+ times without them feeling as though they were loosening but it's all fine and dandy now. Thanks for the help otherwise folks!
Teuchter is offline  
rhett71
Status: - Update
Guest
 
Posts: n/a
Glad to hear its sorted they can be really tight if not replaced regularly. Luckily for me I haven't had to change a spark plug for nearly ten years and I've only changed 4 glowplugs in the same period!
 
Status: Village Idiot
AO Member
 
Jim Spackman's Avatar
 
Join Date: Dec 2012
Location: United Kingdom
County: Cardiff
Posts: 371

Member car:

75 TS

Quote:
Originally Posted by seadart View Post
All this goes back to ancient history when spanner sizes were the thread size .. Whitworth etc ..
when unified national threads came along. which was joint Brit/Yank.. in the interests of winning a war with only one set of spanners.. sorry wrenches.... for a Yank plane with a Brit engine etc..
spanner sizes were quoted as AF..size across nut flats.
Metric was the same
For some unfathomable reason plug spanners carried on being sized as the plug thread size.. sometimes??
just shove it on and see if it fits..
Which allowed my uncle to steal all the really nice tools he needed from the USAAF because his RAF issue one's were rubbish.
Jim Spackman is offline  
Status: -
AO Gold Member
 
Join Date: Jul 2004
Location: United Kingdom
County: Derbyshire
Posts: 6,499
Quote:
Originally Posted by Jim Spackman View Post
Which allowed my uncle to steal all the really nice tools he needed from the USAAF because his RAF issue one's were rubbish.
Funny you should mention that. My late uncle Bill, ex-RAF, had a toolbox full of tools which he said were given to him by his mate Arthur Mitchell!
Dave Brand is offline  
Status: -
AO Silver Member
 
Alfafamily's Avatar
 
Join Date: May 2010
Location: United Kingdom
County: Warwickshire
Posts: 5,758
Quote:
Originally Posted by seadart View Post
Ha Ha great..

It's a good job that we managed to win WWII, or we would all be driving around in BMW's, Honda's and Alfa's by now..
No, it would have Ladas and Moskvich. If we hadn't beat the Germans from the West the Russians would still have beat them from the East. Having said this, the USA still thinks it won WW2 on it's own.
Alfafamily is offline  
Status: SOLD my 156!
AO Gold Member
 
gazza82's Avatar
 
Join Date: Jan 2003
Location: United Kingdom
County: Buckinghamshire
Posts: 9,061
Had the same problem on Saturday .. could not get the smaller plug to turn .. only when I looked really had did I notice the broken black plastic in the plug well next to the plug. Came off the plastic cover that holds coil packs, etc ...

A long thin screwdriver with a blob of grease did the trick!

But not great when you first encounter this ... you start to think the worse straightaway!
gazza82 is offline  
Reply

Go Back   Alfa Romeo Forum > Supported Alfa Romeo Models > Technical & Vehicle Assistance > Engines (TS, JTS, JTD & V6)

Tags
plugs , spark , spinning

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome