my v6 keeps eating 1 spark plug every time.
its always the same 1, on the passenger side the middle 1.
the other plugs are fine.
when it stops firing, and I pull the plug out.
the ersistor value is always infinite.

if I put some wd40 on the plug, the value is back to normal, and the plug works again ( for a while )
I can't keep pulling that plug weekly or so, so does anyone have an idea what the problem might be, and how to stop it?

greets from belgium. ( where F-body's are rare to find in the wild )

 

Bad wire?

 

Picture and or description of what it looks like please, and don't put wd40 on it or we might not be able to diagnose as well by looking at a pic of it..

 

wire is good ( put new wires on it, and when I pull a plug I always recheck my wires )

sparkplug pic wil come later this week ( probably saturday )
if anyone got some idea's pls tel me.

 

Need some more details. Are you checking the resistance while the plug is in the motor? Where do you connect the probes to? I'm guessing the top of the plug and the engine block. Then you spray the threaded section and the plug works.

 

nope.

Pull the plug.
and put the probes on the terminal and the other on the centre electrode.

If I would put the other probe on the side electrode I would measure over thin air. wich would give me an infine resistance anyway

 

Sounds like a broken plug. I've never heard of anything else that would destroy a spark plug.

 

yes, but it already destroyed like 5 new sparkplugs in that cilinder.
so it cant be the sparkplug itself.
I think its a to lean or 2 rich condition in just that 1 cilinder. but im not sure.
or maybe a bad valve or something. I really dont know.

I only know that from the moment my engine is running funny or almost tries to kill itself when breaking to a stop ( when comming from highwayspeed ), its mostly that plug I have to pull, put WD40 on it, put it back in. and you already hear the engine idling better and stuff.

 

I sprayed a dab of PB Blaster on mine when i changed them. I later found out that though its not the worst thing, i shouldnt have done that. So the next time i change my own plugs, i wont do that again.

Im suspecting that cylinder might have low compression. Just a thought. If it keeps eating the spark plug.. could a Heli-core have come loose?
And is that spark plug "Bubbling at the boot"?

And what DO the resistance tests with Multimeter say? How are you testing it (where do you put the positive and negative leads?)

Hope this helps, and i still have my old somewhat burnt plugs. Maybe cleaning up the motor will make these be fine now.

 

Check the compression of the cylinder with the faulty plug and compare it to the other ones. Check both the wet and dry compression.

 

I compression test is yet to be done. but I fear for it


whats the diffirence between wet and dry compression ? and how do you do them

@84camro.
how I measured the resistance of the sparkplug you can read above.
but
( it also eats new sparkplugs without wd40. )


whats a helicore ?

 

"Heli-core", or "Heli-coil," happens when a plug gets broken off, melted, stripped (most likely scenario) inside a cylinder. A good heli-core can be done withou scrap metal getting into the water jacket.

A heli-core or heli-coil is basically a tap-and dye. The old plug gets drilled or screwed out (sometimes overheats melt a plug to the wall, and im referring the most to an older ford Escort that hd ginormous, "I want to be a ***** racer"-type plugs installed, and one cylinder just never really recovered... Helicore provided new threads, basically) .. and makes threads for a new plug.

I had an off the wall idea tat if yours had been helicored (had the car your whole life? or is it a questionable history, and now its yours?) that maybe it had failed somehow, and needs to be re-helicored.

Or course, Escorts have aluminum heads, ours dont. Just like my Jetta. That car survived an overheat of massive proportions!

And i, too, would like to know the "wet" and "dry" compression test method. I once had a guy travel some distance (three hours or so) to test my 95 Escort head.. and did a compression test without even starting the car, just turning over the engine? Im not convinced he knew what he was doing, but was instead trying to find a reason to not buy the car, or talk me down in price (?)

Hope this helps, my enthusiasm DOES have experience. - 84CAMAROinFL

 

altough the car has a very questionable history. I'm pretty sure about it not having helicores.

I just found out what the diffirence between wet and dry compressiontest is.
and the way the guy did it was the right method.
but with dry compression you do it like that. just turning the engine with hand to compression.
http://www.car-techie.com/compression.php?003

 

3. "3. Remove all spark plugs and disable the high tension coil and the fuel pump."

.. so, turning the engine with the other spark plugs IN, = no go.

Now, WET test, im interested in.

I wonder what could cause low compression in ONE cylinder? Has this engine ever been apart? Overheated ?

Perhaps some different lubes may help you, to try to increase compression?

 

you dont have to loosen al spark plugs, it just makes it easyer to turn the engine