srl311too

After seeing the posts about loose spark plugs, I decided to check mine while I was doing my annual oil change. 2005 with 14000 miles. Anyway, I am the original owner and no one has wrenched on this car since I purchased it. O.K., all the small talk done, I applied a torque wrench to the original plugs and found 3 of them were over 20lbs and one was close to 30. Too tight from the factory? Opinions, would you loosen them?

Thanks.

skkppy

They should be set to 19 ft. lbs., just make sure that when you put them back in the engine is cold to reduce risk of damaging threads. I cant really say why they were over torqued but as long as the threads didn't come out with a plug you are fine. Also I would minimize the amount of times you pull the plugs because the oem plug will last at least 70k miles and are rated to 100k miles. The more you pull plugs the more you risk making an error with them and damaging the aluminum head.

Good luck and happy vtecing.

Billman250

Torque cannot be checked with a torque wrench on any bolt that is not moving. It doesnt work that way. I can absolutely guarantee they are not over-tight from the factory. Your method is off.

Loosen them, set your wrench to 21 or so, then tighten till the wrench clicks. you'll want to move the wrench about double the speed of the second hand on the clock. Slow and consistent.

2003AP1

Its not safe to say that if you set your wrench to 21 lbs and went to tighten them and it clicked right away its above 21 lbs?

dwight

I wouldn't be surprised if the thermal cycling of the engine causes the torque needed to move the plug to be higher than the torque that the plug was installed at.

Torque specs are used to describe the torque that should be applied during installation and may not necessarily reflect anything else.

Billman250

Absolutely not.

ApWhat

hmm, i wonder if where about to see a spark plug exploded thread when he tried to use his new torque wrench knowledge hehe

2003AP1

Hmm didnt know that, and I am pretty sure I am not the only one. Thanks for the heads up.

Billman250

Yes I'm sure a lot of people think that about torque wrenches.

All torque settings are for installing a fastener and tightening it.

Resistance (not torque) increases as things sit motionless. Some physics are involved with why a torque wrench cannot be used to check a currently tightened bolt. Not sure I can explain them

Bottom line, the breakaway torque is higher on a bolt that is not moving. So it may take 30ft-lbs to break a bolt loose that is only 25 ft-lbs.

This is where "mechanics feel" comes in.

srl311too

It was a beam type so no clicking involved. I wanted to satisfy in my mind that they were not loose. Nothing moved so they are still at factory torque specs.