sparkplug popped out twice!

[bozothenutter]

Hi, just had the sparkplug pop out for a second time in a month.
I understand the No 3 cylinder is the usual culpritm (is the the second from the cambelt out?)
threads on the sparkplug look good, no swarf on them, and it screws right back in, tightens normally etc.

Time for a timesert?

on a related note : I have a 1/4 drive torquewrench whicj has the right range for the sparkplugs (20-40Nm) but cannot for the life of me find a 1/4 drive sparkplugsocket, does such a thing exist?

 

[mattjk]

You can get a quarter to three eights adapter or vice versa.

 

[reedy107]

Popped out ! Wtf. I would be looking into the thread in the head. Not good

 

[bozothenutter]

Popped out ! Wtf. I would be looking into the thread in the head. Not good

that is the thing...it threads back in quite normally.....

 

[Diagro]

Stick some of that Locking paste they do for this in there? Hopefully wont pop out again?

 

[MG cup]

I'd be wary of putting 40nm through a 1/4 drive socket depending on the thread size.... the spark plug is large thread and I wouldn't chance it. You'll be able to feel it go tight and then the crush washer will 'squish' a little which again you will feel.

If you have a new plug then throw that in as the crush washer is at full capacity and will bite better and resist slackening from vibration.

FYI a you will be doing very well to see any swarf when a spark plug pops as the combustion forces will blow it clean.

Also you can grind a groove into an old spark plug at 90 degrees to the threads which will then act as a clean out tool incase anything is slightly galled.

 

[MG cup]

Stick some of that Locking paste they do for this in there? Hopefully wont pop out again?

I would strongly suggest again this, the depth of thread on the cylinder will almost always in most cars pull the thread out with the plug given the metal dissimilarity.

 

[bozothenutter]

Wasn't planning on putting 40Nm on it sparkplugs are 25Nm

know where I can get a 1/2 torquewrench that has a range of 10-40Nm?

 

[MG cup]

Yeah I wasn't suggesting 40nm for the SP's It was more in your tools interest as if you have the option you'll use it at one time .

Not really sure on 1/2, my tengtools 3/8 starts at 20nm and goes to 190nm or there abouts iirc and that has done me on the Clio engine's. That's the things with TW's, you find you usually need the set 1/4, 3/8, 1/2 if you're anal about torques. To me torqueing down a spark plug is of no importance but depends how calibrated your elbow is really, you get a feel for what's right on certain things.

Using a TW at extremes of either end of its scale will always be doubtful.

 

[Dan@SJM]

The snap on tech angle I'm selling does 16.9nm

Wasn't planning on putting 40Nm on it sparkplugs are 25Nm

know where I can get a 1/2 torquewrench that has a range of 10-40Nm?

 

[l33th3tr33]

little dab of loctite and mine hasn't come back out since. Worth trying as a last resort or quick fix.

 

[bozothenutter]

The snap on tech angle I'm selling does 16.9nm

at a Snap-on price I reckon.....

@Dan@SJM is threadlock really a viable option?, any special (heat resistant) type needed?

 

[Dan@SJM]

It's £393+vat list (very latest techangle, so does angle tighten too) I'm selling at £300.

I'd try a new plug first.