Spark plugs are too damn tight...

[E30_Narek]

So I think I might have figured out my problem. I believe my spark plugs are bad. I managed to get one of the plugs out and it was some shitty brand. I have a set of Bosch Super Plugs at home but my plugs are one way too tight! I had them changed along with my headgasket over a year ago and my theory is that the mechanic used an impact gun on the spark plugs :/. How should I go about taking these off?

[turbo55]

Maybe the threads are galled and that's why they're too tight. Usually you don't want to remove spark plugs when the engine is hot but in this case you might have to. I'd run the engine for 5-10 minutes then turn it off and try to get them out. The hole will expand more than the plug inside it. Heat is always your best friend for stuck bolts.

Make sure to check the gap of the new plugs and use anti-seize.

[estoguy]

And FYI when you do them yourself, you shouldn't have to tighten then more than a quarter turn of your ratchet. I've been doing this consistently with mine for 3 years, and I've never used anti-seize.

[E30_Narek]

Maybe the threads are galled and that's why they're too tight. Usually you don't want to remove spark plugs when the engine is hot but in this case you might have to. I'd run the engine for 5-10 minutes then turn it off and try to get them out. The hole will expand more than the plug inside it. Heat is always your best friend for stuck bolts.

Make sure to check the gap of the new plugs and use anti-seize.

I tried it when the engine was at operating temperature, they still wouldn't budge but I guess I could try again.

And FYI when you do them yourself, you shouldn't have to tighten then more than a quarter turn of your ratchet. I've been doing this consistently with mine for 3 years, and I've never used anti-seize.

I know, just don't know why a mechanic used a damn impact gun. Thanks.

[digger]

get some NGK ZGR5A, they are better quality than Bosch and have the seal washer than crushes so you get a feel how tight they are as they tighten progressively. it tells you how tight to tighten on the box.

Also dont use antiseize, some will cause issues as the threads are supposed to be hard metal to metal for proper plug function (electrical continuity and heat transfer). Not all anti seize provide this copaslip hi temp antiseize seem to work well by all reports.

also if the plugs are too long some threads can go into the chamber and fill with carbon making them hard to unwind.

[E30_Narek]

Got them off! Just changed them and my car is still doing the same shit...