nschloss

I tried to change the oil on my 04 545 today for the first time. I see that previous owner / oil changer has rendered the hex drive in the oil drain plug almost 'round' - my 8MM hex drive starts to turn but the bolt doesn't - it's very tight. I'm positive if I put more torque on it is just going to strip and allow the hex head to strip and lose bite completely. I'm sure I'm turning the correct direction as well! Just to be clear - it is not the threads that are stripped but the hex 'hole' where you insert your hex tool. What is the best way to remove the existing bolt? Can it be replaced by a 'normal' bolt that I can use a socket drive on?

txag_530i

Sometimes you can drive a socket hex driver into the hole in order to get solid contact. Then use a long-handled ratchet to turn the bolt out while pushing the socket into the hole as much as you can. If the hex bit starts to strip the hole then stop.

You may then need to invest something like this- Sears 66196

First drive a small pilot hole into the hex bolt's head. Then drive the extractor into the pilot hole. The extractor threads are reversed (left-handed) so that as the tool drives c/w into the stuck bolt the bolt will turn c-c/w and come out. It doesn't have to much of a pilot hole, but it can be a long process to drill it so have some patience. You will destroy the oil drain plug in the process. BMW will most likely have the drain plug in stock (you will need to have it on hand prior to removing the old plug). My 2006 530i uses a 15 or 17mm hex head bolt so that's probably what BMW will sell you. Make sure that you get a new washer, too, if it is required.

Good luck.

zen

Could it require a "TORX" and not a "HEX".

zen

I don't know what happened to my earlierpost. Could it be a "TORX" or "STAR" and not a "HEX" ?

nschloss

It's definitely a hex - all documentation I've found confirms that.

nschloss

I wondered about that - I may give it a shot after acquiring a new plug. I would really like to use a different bolt though. Any one out there ever switched to a regular non-hex bolt?

z06bigbird

I clearly do not know what I am talking about, but I suspect the hex tool was designed to avoid having someone put a 10 inch long 1/2 drive ratchet on the bolt and strip the threads in the pan.

Just a hunch.

zen

on my 2006 530I it takes a 15 or 17 mm box wrench or socket. I presume it is a metric Thread, so you should be able to get a threaded plug at any place that supplies bolts and screws.

nschloss

I agree - I'll try determine thread size and look for a custom plug.

flint

I have the same problem but I'm not sure its a Hex bolt. I think the problem is that we should be using a Torx type wrench