View Full Version : Oil Drain plug seized...can you use an air impact to remove without damage?

07-18-12, 08:37 PM
Unfortunately am not able to break the drain plug loose for oil change. Son was helping me and he says head of bolt isn't rounded off so I am thinking of using my impact wrench with a 15mm 6 pt socket to break it loose. Any insights or thoughts are appreciated. I have til Saturday to decide, already have a new plug.


07-18-12, 08:57 PM
Having changed literally thousands of cars/trucks oil I can tell you bad things have happened to me if I wasn't able to remove the drain plug with anything short of a cheater bar. Usually they are cross threaded/stripped either from over-tightening or just plain worn out.
How long of a wrench/breaker bar do you have to use?
I would use a breaker bar and give it a rap with a hammer, you might get lucky.
I don't think I would use the impact...

07-18-12, 09:27 PM
Did try using interlocked combination wrenches with my son suspending his whole upper body weight on the wrench. Even tried putting the wrench on a floor jack and jacking it up against the weight of the car but couldn['t break it loose that way either, that is where we left it til next Saturday. It was done by a Valvoline quick oil chage center last time, don't trust them to correct the issue. I think they either over torqued or cross threaded it.

07-18-12, 09:42 PM
I'd use an impact. If there is any damage, it's already done. I don't think you'll do any more.

07-18-12, 10:13 PM
Hi Ranger,

long time since I have been on here. I am thinking along the same lines, using it to break it loose will probably be the least likely way to cause any damage to the head if the bolt and hopefully to the threads in the pan. I am thinkig of trying to put in a drain valve with JB Weld if the pan is stripped, any better ideas?


07-18-12, 10:25 PM
I thought it had been some time since I've seen you.
If the pan threads are stripped I think you can buy oversized oversized self threading plugs to rethread and save it.

07-19-12, 10:35 AM
The oil you fling when it breaks loose with the impact will be a sight to see.

Have somebody take a video of it & post it up when you're finished.

Pro tip: don't have your face anywhere near the "splash zone"!

07-19-12, 11:21 AM
Interesting possibility! Anybody else have any suggestions? Hopefully since I will have pressure against the bolt and will be pulsing it at its lowest torque setting it will not fly out when it comes out and fling oil too badly but we'll see what happens if I don't come up with a better suggestion.

I am considering using either an oversized piggy back plug with the female part loctited in or just a standard self tapping oversize plug if the pan is stripped when I get it out. Anybody have any comments from their own experience on either of these options?

07-19-12, 03:01 PM
Just don't spin the plug off. Once you loosen it and see it move a bit, stop and use a wrench. A little common sense applies here.

07-19-12, 09:38 PM
I agree but my experience with impact wrenchs is that when they break loose you often can't cut it off before the fastener is completely off. Any way, will do it in brief pulses to keep from twisting the head off and try to control it when it does come loose (hopefully).

07-20-12, 10:00 AM
The standard self tapping plugs wear out eventually, you have to be very careful to get it install correctly so it don't leak and all it takes is that same dumbass at quickly lube and it's toast. If you are careful they can last. The piggy back plug sucks because the internal drain is so small and will leave some oil in the pan and takes forever for it to drain, but you can get it to seal better usually and it's a final fix. Ideally see if you can find a bigger size plug and tap the pan carefully. Or install a quick drain type that you just turn a level...
Best of luck with this. I've swapped out several pans on my POV's because of it.

07-20-12, 10:04 AM
IF you have to drill and tap a new oil drain plug hole, use grease on the drill and tap to trap most of the machining chips that will result. No sense having the chips in the oil pan...........and you would be better off doing the work up on a lift with room to see and work.

07-20-12, 08:59 PM
Unfortunately its either ramps or jackstands and wheel chocks (with either). I have a 15mm wobble impact socket and extension so I think I can get a reasonable angle on the plug with the impact wrench. If it is stripped I will probably use the self tapping over size plug to chase out the threads (with grease as you suggested) and then put in the piggyback plug with locktite so it will be secure in the pan. What are your thoughts on that idea Sub or Ranger or anyone else who would like to chime in?

07-20-12, 09:21 PM
:noidea: I suppose you can always remove the piggyback if it leaks and try another route.

07-20-12, 10:41 PM
Check the threads, the self tapping are usually pipe thread. I wouldn't use one to make threads for the other unless you make sure the threads/pitch etc are the same. I believe the current thread is m12, they sell m14 plugs. I was at advance today getting a new gasket for a plug and looked at them.

07-21-12, 01:35 AM
The oversize plugs are the same thread but only about .010" oversize so they cut a slightly deeper thread as I understand it. If I change to 14mm then would have to drill and re tap producing much more opportunity to go crooked and/or introduce aluminum chips into the pan. The oversize plugs are both self tapping but there is a longer taper on the plug than on the piggy back plus which is why I was considering going that route. Hopefully the threads won't be buggered and I can use a new M12 1.75 plug. I am just trying to think this through before I commit in the morning so I avoid any unforeseen complications. I will have to mike the plugs on the outer dia of the threads to see that they are the same and compare to the new plug as well, then try to mesh the threads to confirm pitch and depth of the oversize plugs threads, good call Rodnok.


07-21-12, 11:37 AM
Once you get the plug out and before you do anything else, try reinserting it by hand to see if it was just impacted on by a ham handed grease monkey. You might get lucky and not have to do anything to it.

07-21-12, 02:27 PM
Dang! This was the oil change from somewhere south of purgatory. I heated the engine up with a 20 minute drive, jacked it as high as we could get it and finally broke it loose with a 1/2 in breaker bar. Threads were in excellent shape, was torquing the new Napa $8.00 drain plug to 15 ft/lbs when the head of the new drain plug snapped flush with the pan before we even got to 15. We had run it in by hand so did not cross thread. 30 minutes playing with nail sets, cold chisels, a hammer and a drill finally got it out. Put in a different brand bolt that torqued up nicely. I am too old for this kind of melodrama doing a simple oil change!
I think today may be a good time to add a new item to my bucket list and start on it now...become a raving alcoholic!!! Pass the scotch, its almost noon!

07-21-12, 09:33 PM
WOW! New plug snapped the head off? I'd be back at NAPA and would not be happy. :annoyed: At least the pan threads where not damaged. THAT'S the important thing. Hope you're enjoying that scotch. You earned it.

07-21-12, 10:29 PM
Sounds like Murphy has been visiting...that'll teach you do do something the right way :p
Hey at least the oil filter wasn't as tight... nothing like a filter you have to take off in pieces.
Have one for me tonight...

07-22-12, 07:34 AM
I didn't even think of keeping the receipt for the drain plug, after all, who ever needed to return a drain plug? But, I took it back anyway, it was magnetic and I had the sheered head stuck to the magnetic insert. I had the manager pull another plug to prove it was a Napa plug and commented on how poor the steel was, looked like cast iron (crystalized) and he proceeded to say it was aluminum! I told him it was a magnetic plug and was steel showing him the head could be picked up with the magnetic insert and he says, that's just an insert, the plug is aluminum. I finally asked him when was the last time he saw aluminum that was attracted to a magnet and finally a twinkle of insight came into his eye. That was the store manager, but I got my refund and bought a different plug elsewhere.

I think it was easier dropping the cradle and studding the engine on this car than changing the oil is.

07-22-12, 10:57 AM
Hey at least the oil filter wasn't as tight... nothing like a filter you have to take off in pieces.

Wait until you come across an oil filter on one of these FWD cars that some airhead at the local Oil Doodle has tightened with a strap wrench - so you have to drive a screwdriver through it to twist it loose.

07-22-12, 06:30 PM
I have had to do that a couple of times in the past and once the #2 phillips started cutting the filter without loosening it, finally had to go to the biggest square shank common screwdriver I had (about 1/2 in on a side and drove that through and got it off. Its amazing how inept these oil change joints can be when they only have to have about 15 minutes of training to understand and do it right.

07-23-12, 01:47 PM
You can train them all day long and they still muck it up... I had a guy who was my best employee and a great mechanic except for the fact that he put oil filters on until they stopped moving. If his name was on the last oil change and he was there he changed it again. I had alot of complaints about him over the years. You could not get his filters off jacking the car up and laying on your back. Fifty percent of filter problems are because the dolt doing it doesn't lube the gasket at all and just a bit of overtightening and that bastard ain't coming off without some swearing.
People would ask me if they should use a wrench when tightening a filter and I would say yes, but don't crank it down just snug it up. I personally put my filters on a little too tight and I know it, but it's me taking them back off so I just punch myself if it's a bitch to get back of. :)

07-24-12, 06:50 PM
I lube the gasket on the filter and hand tighten it on there thenni give one decent 1/4 turn by hand, not loose but tight enough so that i know it aint going to leak.