Hello,

I am struggling with the spark plug replacement. I have 2 volvo 240s. I never had a problem changing last time.

This time I took out #1 spark plug (i.e. difficult one against the wall). Then I carefully screwed in a new one a little but realized that it was not going in right. So I took it out and found that the gap was pushed in a little. So I corrected the gap. I tried to put it back in but was not successful.

Visually I cannot see the obvious damage to the spark plug hole. Did I damage the thread in engine? The spark plug itself is fine, which I know for sure.

Is there any trick to align the spark plug? Should I force?

Thanks!

One thing that I have done is to take a 6" strip of masking tape.

When you remove the plugs, attach the strip to the rocker cover at an angle to match the angle of your socket and extension.

Another thing you can do is to change the plugs one at a time, doing numbers 2 and 3 first. That way, if you have trouble starting a plug, you can put your socket and extension on its neighbor to see the angle.

Next time be extra careful with that plug.
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'96 855R,'64 PV544 driver, '67 P1800 basket case, '95 855, '95 854, the first three are mine, heh, heh, 485,000 miles put on 9 bricks

Never force or you will thoroughly mess up the threads and need expensive shop time to repair.

If the plug will not thread in properly with many, many attempts (be patient) by hand, it suggests the plug hole's top thread or two is distorted. You then have to obtain the proper thread tap (relatively cheap) and run it in to clean up the plug hole threads, but here is where you REALLY have to be sure you have that tap aligned properly so you are cleaning up the original thread and not cutting new ones.

If the tap is following the threads properly, it will turn fairly easily.

The rearmost plug by the firewall is actually #4.
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Bob: son's XC70, dtr's '94-940, my 81GL, 83-DL, 89-745(V8) and 98-S90. Also 77-MGB and some old motorcycles.

I think that is exactly what I did. Thank you for the number correction. So mine should be #4, the hard one.

Initially I did not align it properly, after 2-3 turns with wrench, I found out. When I took it out, my spark plug gap was pushed in a little.

I will try one more time and tow it to my friendly mechanic. He told me that he has thread tap.

Never start a plug with a socket/ratchet. On the hard to reach ones, I push a piece of gas line onto the plug. It lets me reach in there and gives me that 'finger feel' that you need to make sure it doesn't strip. You can try turning the plug counterclockwise until you feel the plug Threads mesh with the threads on the Head. When you feel that mesh, then turn it in Clockwise.
I always do this counterclockwise method on Plastic parts that have sheetmetal screws holding it together.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html http://cleanflametrap.com/tony/

It sounds like you have the situation in hand now but I wanted to make this suggestion for starting plugs at odd angles which I was taught many years ago---use a short (6 inches or so) length of fuel hose--push the top of the plug into one end of the hose--now you have a flexible extension which will allow a properly aligned plug to screw in but will jam up without causing damage if it isn't. -- Dave

I didn't read all the posts until after I read yours.. I basically wrote the same thing.
This gas line method is a must on my motorcycle.. there is no finger room to get the plugs started and it's tight with tools. you need to assure that it is threaded in proper before juggling the socket on the plug for final tightening
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html http://cleanflametrap.com/tony/

No FORCE! That one gets stripped easily. No ratchet, start it by hand. The alignment is the issue. All I can tell you go by feel gently. I normally use the spark plug socket with extension but no ratchet.
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Post Back. That's whats makes this forum work.

Walt (Aleekat) has the right idea.

I've had good luck by using the socket which has a internal rubber section to "grab" the plug top firmly, and at least a 6" extension.

I'd take out the sparkplug on #2 and get a good feel for the entry angle with the plug socket and extension setup, then switch over to #1 while that angle is still fresh in mind.

Marty

Ditto. That's exactly what I did many years ago, did the alignment with the plug next to it, the tried to duplicate the angle.
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Post Back. That's whats makes this forum work.

I may be wrong but isn't no. 4 plug at a different angle than 1,2, and 3?

All the plugs are at the same angle--or at least--supposed to be. -- Dave