Not wanting to jack the recent thread. I started this one.

My recent purchase of a 1992 240 had a problem when we went to check the plugs. There were very difficult to extract. I'm quite certain the PO or mechanic cross-threaded them during their install. We changed the plugs and they went in but definitely not as easily as they should have.

Never having re-threaded a spark plug hole before, what all is involved? How does one keep any filings from entering the combustion chamber? I suspect I will have to do this the next time we change them.

Thanks in advance for replies. I'm not always near the computer, so a response from me might not be timely.

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Happy Motoring! 92' and 93' 240's past cars "74 140, '75 140, '86 240, '87 240 wagon, '02 S60.

Why do you think they're cross-threaded? Because they don't go in easily?

I've worked on many 240s w/ hard-to-remove plugs. Some kinds of plugs (Autolite?) freeze to the threads. Others are just tight from many miles of use.

If they're cross-threaded you'll feel it coming out - the plug will be eccentric.

I have (rarely) seen stripped threads and the heli-coil kits work well. Put the piston at TDC and blow it out. Or just don't worry about it. The AL shavings will burn up.
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240 drivers / parts cars - JH, Ohio

I thought this because they were extremely difficult to remove. I truly thought that the plugs would crack from the torque I was applying on the wrench. They went in much easier, but not smoothly at all.

I've never had a car that sat a long time to compare it to, perhaps the vehicle sat too long without use? I know the PO bought it at auction to flip and he had it for over a year and only went about 60 miles. The best I could tell from the receipts in glove box is that it had one owner prior to the auction.

Bought it for $350, resoldered the fuel pump relay to get it started, after much help from BB. Since then I have put battery, tires, ball joint and new front bearings, new plugs, cap and rotor, and air filter. Also had an Oil Change and cleaned the throttle body and IAC. MPG seems low but I think the son may be heavy on the pedal. The FPR vac hose has no gas smell. It runs smoothly and feels tight.
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Happy Motoring! 92' and 93' 240's past cars "74 140, '75 140, '86 240, '87 240 wagon, '02 S60.

Thanks for the responses.

I guess I'll look into one of these kits when I go to do it.

All things entering the combustion chamber other than air and fuel would concern me.

And I do not think a magnet works on aluminum.

Thanks again
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Happy Motoring! 92' and 93' 240's past cars "74 140, '75 140, '86 240, '87 240 wagon, '02 S60.

Load up with grease..
Take an air hose into the plug hole
Use a computer vacuum attachment in hole

"How does one keep any filings from entering the combustion chamber?

That's what I was wondering before I did the plug re-thread on my 85 240.
I bought this rethread kit.I was not cheap,(about $50 bucks).The kit has a tap, and a sleeve.The filings from the tap are minimal, and most get caught in the sludge from the tap lube oil/grease.Whatever small filings that end up going down into the cylinder,are no big deal,,,after all, the filings are aluminium,and they are burnt and/or blasted out in the exhaust.

I was expecting the worst,but it worked very well.

It would seem you could either take the head off to cut the threads of use one of those small magnets to fish the shavings out by way of the plug hole.