Spark plugs been in 15 years, will they break on removal?

[Trevor555]

Hi all, A friend has asked me the above.

Car is a Honda CRV, done around 40,000 miles, 57 plate.

How likely are they to come out ok?

It's running ok at the moment.

Should the advice be to leave them alone if running ok?

[VTC]

they might
but then they may not

soak them in penetrating fluid before trying to remove one.

and do it when being without the car for a while is not a real problem.

[BDKM]

Yes they will , just assume they will and prep for that ! If by some miracle they don't .....buy some lottery tickets ASAP!

[Trevor555]

Thanks chaps, confirms my fears for them.

I'll advise them tomorrow that they're quite likely to break, unless they're lucky.

[Baldchap]

Penetrating oil every day for a week beforehand. Correct size socket. Warm engine. A breaker bar will allow you to go much too hard, but if you're careful, will allow a lot more controlled application of force than a smaller tool...

[Krikkit]

If they're the originals I'll bet on them being fine. Torque up the new ones and they'll be the same.

[gotoPzero]

Stop being a pussy and get the half inch gun on it… lol.

Seriously though, defo soak.

If they are factory you might get away with it as they will have been torqued correctly and ime factory torque on plugs is usually not much over hand tight.

If they are not budging then a tiny nip up often helps, talking 1/16th of a turn.

Good luck.

[The spinner of plates]

If it’s running fine, I’d leave ‘em.

[steveo3002]

some chance , id change them though

[Philvrs]

Be prepared to tighten and loosen on the way out to clean any carbon off the ends, don’t just keep going if they go tight.

[Rozzers]

Plus Gas is the fluid of choice here, plenty, for a good few days days beforehand, Proper socket and do it as hot as you can. Ideally someone with experience and feel should do it.

[steveo3002]

bet half the cars on the road with fsh never had them changed anyway

[dingg]

The spinner of plates said:

If it’s running fine, I’d leave ‘em.

Yep, don't go looking for problems.....

[steveo3002]

dingg said:

The spinner of plates said:

If it’s running fine, I’d leave ‘em.

Yep, don't go looking for problems.....

yeah wait until it wont start one snowy night

[alanshuff]

If they have never been replaced, i'd think that they will come out no problem at all. I'd rather have that scenario than ones which have been replaced but overtightened. They are usually well shielded these days with the coils.

I just replaced mines a few months ago - 2011 Toyota Auris which has a recommended change at 100k miles (i think) using the long life iridium spark plugs. Car's on 98k miles and they certainly looked like they had never been replaced - no contamination under the coils from any previous change and looked like new from the top. They came out no problem at all.

[Krikkit]

To those saying soak it in Plusgas etc, what do you think that'll do? The threads are sealed from any contact by a crush washer, you won't get any penetration there... The only case would be if there's been a load of water in the plug holes and it's externally rusted.

[gotoPzero]

Krikkit said:

To those saying soak it in Plusgas etc, what do you think that'll do? The threads are sealed from any contact by a crush washer, you won't get any penetration there... The only case would be if there's been a load of water in the plug holes and it's externally rusted.

Quite a few WSMs say to soak. IIRC ford suggest pm3 on their higher end stuff.

[Zener]

Dont leave them like advised its one of the biggest cause of coil pack/ign module failures , spark drivers over-heat due to current draw becoming excessive due to enlarged plug gaps , get a 16mm plug socket down there they will come undone dont fit st NGK or Denso is the preferred, if your not comfortable tightening plugs then torque them to spec figures like suggested already

[CrutyRammers]

Am I the only one who's never had a problem with spark plugs?
Suspension bolts, exhaust studs, yes.
Try it and see. If they don't come out easily, then look at other options before forcing things.

[Decky_Q]

From professional experience they will usually come out ok, but I did have a plug snap when servicing a motorbike 24years ago, and I had aluminium threads come out of the head with the steel plug threads a year or two ago. Both were disasters but then I've had hundreds come out with no problem.

So there is some risk but its faily low like 1% at a guess.