FV432 stuck plug help!

[Yohan]

Hi Gents,

I have an FV432 MkI with a stuck plug. I did not install these, so I don't know if it was cross-threaded or over-tourqued? I soaked it last summer in PB Blaster for hours and put a breaker bar on it with no kuck.

I have not hit it with an air impact wrench, but I'm afraid that's my only option. If I do this, what's the worse-case scenario? Does anyone out there know of a better way? Please help and thanks in advance!

John, NY

[jim sewell]

John , when you say plug , do you mean spark plug or oil level plug ?
The danger with putting too much torque on spark plugs is that they can break off just below the hex and leave the thread behind .
The s/plug may have a gasket or taper , if it is possible to make a sleeve which will fit over the porcelain and contact the area on the inner part of the hex and strike this with a hammer to force the gasket or the taper to compress a little, it may be enough to allow the s/plug to undo.

Drain plugs with a gasket can be done the same way , giving them a sharp crack with a hammer .
Regards
Jim S.

[Yohan]

Thank you Jim. I mean the spark plug. Sorry for not clarifying that. I had one suggestion to start engine and run to temp, then turn it off and work it with the longest breaker bar I can get. I was warned against an impact wrench because you can't "feel" when something is about to break off (leaving the threads behind).

I'll give it another try this spring when it warms up. Thank you again for your help!

John

[S LATHERON]

I had to remove a stuck gearbox shaft that was stuck in its bearing and know amount of gentle persuasion with blocks of wood and heavy hammer worked.
Finally i tried a hot air gun [electic paint stripper type] Heated up the whole of the shaft and bearing. Then when it was all nice and hot poured cold oil on the shaft, causing it to shrink at a different speed to the bearing. One swift blow with the hammer and wood block and the shaft came free.
If you can warm the engine up to temperature as you suggested and then carefully cool the offending plug you may be able to free it in a similar manner Maybe a cold plug socket/ wrench will be enough to drop the plug temperature quickly and cause the plug to " shrink" enough to free it. As stated the use of a hand held ratchet bar to feel the plug as it comes loose.

[Paul Singleton]

I have had luck in the past using air intake cleaner. The spray for cleaning the throttle plates on a late model car. Spray lots on the base of the spark plug and it may work into the threads. Also spray lots down the carb with the engine running to help clean the carbon on the inside. I have found that it is usually carbon build up in the threads that causes the problem of stuck plugs. If the spark plug starts to move, try not to force, spray more intake cleaner around the plug and keep working the plug back and forth a few times. Hope this helps.

[CWO (ret) Gilles Aubé]

If you brake the spark plug, you can fix it with tread replacement, the HELI-Coil compagny makes replacement.
If the spark plug is taper that is an other game, you will need special tool but it could be fix by a machine shop.
If you cannot find the replacement tread if needed please let me know and I will help you.

Gilles
UBIQUE

[malcolm erik bogaert]

before you resort to brute force there is a product on the market which freezes the item stuck and at the same time lets in penetrative oil when the item compresses....keep applying same until it gives....sorry cant remember the name but read about it in Classic Car magazine......cheers malcolm

[Paul Singleton]

I think this is what Malcolm is referring to, Rost Off Ice from Wurth.

http://www.wurthredlabel.com/product...=18710&cat=249