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View Full Version : Ever stripped the head on your oil drain plug



Gen3CoupeTX
01-26-2019, 06:38 PM
Until an hour ago, I'd answer 'No' to that question. Now I have to answer 'Yes'. Nicely humbling for a guy who's turned wrenches for 3 1/2 decades, forced induction systems included. I'm going to blame advanced aging! Seriously though > That plug is supposed to turn counter-clockwise for removal? Is it some special size that I don't know? I'll take it to a mechanic friend with a lift before trying it again ... With a new drain plug in hand of course. If anyone has a part number, much appreciated ... 2006 coupe. And if anyone has useful tips, I'll gladly read them while I choke down this humble pie :owned: , Mike

Steve-Indy
01-26-2019, 07:01 PM
Original part number was 6507741AA. Torque specification is 25 ft-lbs.

One has to wonder if previous "oil changer" over torqued or cross-threaded the plug.

Friends around Indy have had many similar complaints concerning drain plugs that had been stripped at dealerships...some with "repairs" using silicone, some with helicoils. Said dealerships included Porsche, Lexus, and a few others according to the owners.

Steve-Indy
01-26-2019, 07:47 PM
By the way, many folks use a bit of Teflon plumber's tape on all drain plugs to avoid galling...steel plug and aluminum pan is a good case in point.

And...since I forgot to answer the actual question posed...no, I have not stripped the drain plug head...but I have worried about same on some tight ones.

Steve M
01-26-2019, 08:43 PM
I've also never stripped the head on any oil drain plugs, but when it comes to cars, anything can (and usually will) happen.

Using my Google-fu, it looks like it is a 14mm x 1.5 thread on that plug. The head takes a 13mm, 6 point socket to remove, and is normally threaded (righty tighty, lefty loosey).

If it were me, I'd grab a pair of vise grips and clamp down hard on it to remove knowing full well you won't be saving it (nor should you for what little they cost). How it comes out will determine what you need to do next...if it is just hard to break loose but comes out pretty easily after that, you might only need to replace the drain plug. You might want to chase the threads with the appropriate tap, but that might be overkill for that situation, and you'd need to be careful to make sure you don't get any shavings in the pan. If it fights you the entire way out, you'll at a minimum need to chase the threads; worst case will require a heli-coil. 14mm x 1.5 is fairly large for a threaded insert, so you might have to do some hunting around to source one locally. If you end up having to go that route, just go ahead and drop the pan to make sure you remove 100% of the metal shavings you'll create drilling it out.

As for teflon tape, as a rule of thumb, I will not use it on oiling or cooling systems on cars. What I worry about is little bits of it breaking off and circulating around in the oil or coolant. Yes, that's what an oil filter is for, but you never know how long it will take to actually end up there, nor do you know where it will travel on its way there. You can get teflon paste, but even that isn't something I'd consider using on an oil drain plug. I wouldn't even use anti-seize...the threads of the oil drain plug don't do the sealing in that application (that's what the o-ring is for), so some oil is going to interact with it and potentially contaminate your oil. Would it do any damage? Probably not, but why risk it? Oil drain plugs do not have to be tightened any more than hand tight.

ICPREY
01-26-2019, 09:49 PM
Never done that, but Irwin makes sockets called Bolt-Grips that work great on stripped out heads. I've used them on exhaust bolts with great success. Penetrating oil and some heat will help if you're worried it's installed way too tight.

Steve M
01-26-2019, 10:00 PM
Never done that, but Irwin makes sockets called Bolt-Grips that work great on stripped out heads. I've used them on exhaust bolts with great success. Penetrating oil and some heat will help if you're worried it's installed way too tight.

Penetrating oil won't make it past the o-ring...there's also already oil on the threads from the pan.

Gen3CoupeTX
01-26-2019, 11:01 PM
You guys rock, thank you. Appreciate the tips, and forgot all about the Irwin sockets. Not a lot of hammer room between frame and oil drain plug, but may give it a go when my pride recovers! Steve, thanks for the detailed reply. Obviously hoping threads are okay and won't need any tap. I'm not as agile under jack stands as I used to be.

Fatboy 18
01-27-2019, 05:28 AM
Using teflon tape is fine providing you wrap a little bit of it around the upper threads near the bolt head, if you wrap it over all the threads and have a little excess at the end of the threads, then that's asking for trouble.

Its all about how you apply it. :) I know we are on internet forums and not everyone has mechanical aptitude, so caution has to be aired, but if you have some common sense and do not wrap the whole thread it will be fine.

As for the stuck bolt, You could try running the engine until the pan gets hot, turn engine off then try to loosen bolt. You could use some Plumbers Freeze Spray (on the Bolt only) it may shrink it a fraction allowing you to break the seal, worse case Drop the pan drill down centre of bolt then use easy outs.
Do Not hit bolt or you may fracture the pan!

A2008
01-27-2019, 09:22 AM
When removing oil pan bolts, it's always best to use a six point wrench or socket. I've seen many of them burgered up from people using 12 point wrench's/sockets that are worn and therefore causing the head to be stripped.

daveg
01-27-2019, 05:09 PM
always best to use a six point wrench or socket.... I never use anything but 6 point.. I personally wouldn't use Teflon tape. As Mark indicated, you could be asking for trouble.

Gen3CoupeTX
01-27-2019, 09:15 PM
12 point ... Guilty. I know I have the 6, but damned if I could find one. I did this not long after lecturing my teenage son about not taking shortcuts ... Do something right or don't do it at all. Exactly!

Redx
01-27-2019, 09:56 PM
Clean threads are best with a straight cut plug, light lubricant, no pipe dope tape or anything, just going to plug it up.

Give the head of the plug a few taps on the head first, this helps break the plug free a bit. Using a vise grip probably going to make it worse.

Pound on a 12mm or 1/2" 6pt socket with a hammer, remove the plug. failing that, use a small pipe wrench, the teeth grip harder as pull. Nothing wrong with 12PT, just the plug was over torqued. I generally reserve 6pt gear for rusted exhaust bolts.studs, etc.

quickster2
01-28-2019, 05:47 AM
Mag Plug Magnetic Oil Pan Drain Plug and Filter (M14 x 1.5 mm) – Premium Stainless Steel Magnetic Plug With Enclosed Removable Neodymium Magnet

My recommendation for the replacement drain plug. Very robust piece to attach your socket to in the future. Have them on a couple of vehicles.