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I'm trying to change the engine oil but running into difficulties removing the oil drain plug. One of the instructions I followed to change the engine oil was to give the car a short drive prior to the oil change; this would heat up the oil so that it would flow more readily into an oil drain pan.

Since I am having difficulties removing the plug, I was wondering if the heat has caused the oil drain plug to expand and tightening itself to its surrounding? Is it better to attempt to remove the oil drain plug when it is in a cooled down state?

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Is this the motors first oil change ? I've run into drain plugs and filters that the factory put on really tight. –  mikes Dec 31 '12 at 19:00
No it isn't. I've done it before but it is being particularly stubborn this time. I was wondering if I heated it up too much and causing the stubbornness. –  methon.dagger Jan 2 '13 at 23:07

5 Answers 5

up vote 1 down vote accepted

I agree with Dan's comment - the right sized socket and a bigger bar.

I'd allow the car to cool, then using a 6-sided socket of the correct size on a 12" solid bar, crack off the seal on the plug. As with any stuck bolt, a short, sharp shock (e.g. kicking the end of the bar with your boot) is usually better than prolonged torque, which tends to be the cause of stripped heads. Once you've got it out, replace with a new, undamaged plug (and new crush washer).

I usually do my oil changes with the engine warm for the same reason you cite, the oil is a bit thinner and so flows better - particularly in the winter!

edit: As always, if you're not sure, take it to the shop - they'll do the same thing, but if they break it, it's their fault instead of yours ;)

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Very fair point on the last bit! –  Dan Jan 4 '13 at 16:13
My bolt is stuck..what do you mean by bigger bar? I'm using a 13mm that fits snuggly but I think it may be stripped. –  Brittany Jul 16 at 19:23
The length of the handle - a 12" or 18" solid bar one instead of a standard 8" ratchet handle... Make sure you're using the right size socket for the bolt, and that it's a 6-sided one so that it grips the bolt head as well as possible –  Nick C Jul 17 at 9:16
If you don't have a breaker bar, you can use a bit of pipe on the end of your ratchet. If you have wrenches, put the closed end on the drain plug, and wedge another wrench's closed end into the 13mm wrench's open end. kinda hard to explain, but one side of the open end goes through the closed end. you just want to make it longer to get more leverage. –  rpmerf Jul 17 at 12:56

Are you using the right wrench? The proper wrench will not damage the plug regardless of the temperature, and if using the wrong wrench, you could be stripping the plug. If the plug is already stripped, you might want to let it cool so you can work on the problem and not burn yourself. The plug could have also been over torqued, and the heat could be adding to the issue. If over torqued, you can cool the plug while the engine is hot (Cold will shrink the plug a small amount), and allow for easier removal.

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I'm using an adjustable wrench and it is stripping the plug. I've also tried using a hex socket with no luck. I'll give your suggestion about cooling the plug a try - just place some ice next to the plug? –  methon.dagger Dec 31 '12 at 9:24
Get the engine nice and warm. Hold a icecube on just the hex part of the plug until the melting action has slowed to a really slow drip. I am assuming you know the lefty loosey, righty tighty rule:) –  mikes Dec 31 '12 at 18:24
Adjustable wrenches put all the torque on 2 points. Socket and box wrenches put it on 6 points. They also fit better, putting the force on the ends of the flats instead of the points. Some 6 sided wrenches even have curved faces, putting the force in the middle of the flats. –  Jay Bazuzi Jan 1 '13 at 19:15
The ice trick didn't help. I have a feeling that the repair shop I took my car in for the service over torqued it. I think I'll take my car in to a shop to get it removed and also have them install a fumoto oil drain valve to avoid this situation in the future. –  methon.dagger Jan 2 '13 at 23:15
@Xolstice You just need the answer to every stubborn bolt - a bigger bar and the correct socket. Don't kid yourself into thinking the shop will do anything different. I'd advise doing this while everything is cold, though. –  Dan Jan 3 '13 at 16:30

Make sure that you're using the proper socket or combination wrench. If it's not american, it will be metric, if it is american, it may or may not be metric. There is rarely a good reason to use an adjustable wrench (usually if you need two of the same size at the same time, or you're dealing with a large size that you don't have a wrench or socket for). If you've already begun to strip your drain plug head, you can buy a new one. Also, don't over tighten it, and use a new crush washer when replacing the plug.

There are two types of sockets, 6 point and 12 point. If the head of the plug is getting stripped to the point that a 12 point socket isn't able to grip it, a 6 point socket may work better.

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Had the same problem on my 95 k1500 with 5.7. What helped me was using a long armed ratchet and spraying the plug and surrounding area with wd40. Took a few tries but eventually you'll get it.

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Heat actually makes bolts easier to remove. That's why you find mechanics often heat stuck bolts with butane torch. I don't know why, but it is routinely done.

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