Steel Plug Aluminum Pan

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Bwana

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I can't keep my engine oil drain plug from dripping. I've cleaned both the plug and the pan flange completely, used a new Al crush washer from BMW, and it still drips. I'm fairly gentle on torquing it in as I'm assuming the pan threads can be easily stripped but it is still pretty tight. A friend of mine said it's because of the differential expansion between the Al pan and the steel plug. That doesn't seem reasonable, given all of the Al pans and steel plugs out there.

Any suggestions? Teflon tape the threads? :shock: That seems kind of "shade tree mechanic". Use a torque wrench to chinch it up? Find a copper crush washer? Anybody else had this problem?
 
Both of mine are dry with aluminum washer. Have you used a torque wrench to the recommended value? Is the plug or drain hole buggered up?
 
Luis A. said:
Both of mine are dry with aluminum washer. Have you used a torque wrench to the recommended value? Is the plug or drain hole buggered up?
Click to expand...

No, I haven't tried a torque wrench. My bad, I know. The blue books show 43-47 ft-lbs for the drain plug. Sounds pretty high, do you guys do this? Could be part of my problem :-D

Both plug and hole clean and burr free. I
 
Bwana
As a retired plumber I would strongly suggest that you do NOT use teflon tape, or any other sealant on the threads of the pan drain.
Small pieces will tear off and wander around your engine until they find ? to plug up.
New crush washer and to torque specs.

You could put some on the crush washer and torque down since it would not be internal.

steve
 
Putting Teflon tape on the threads will lower the friction. The lower friction increases the clamp up force at a the standard torque specification and will increase the chances of stripping the aluminum thread. You can lower the torque but it would be a guess as to how much with out some elaborate test equipment.
 
Bwana said:
I can't keep my engine oil drain plug from dripping.
Click to expand...

Are you sure the drain plug is the source of the leak? Since it is the lowest point on the engine, oil that originates from other places will end up on the drain plug.

You might try adding fluorescent dye to your oil, and using a black light to find the source of the leak.

51EZEPji-%2BL.jpg
 
Much good advice here. My 2-cents:

1. Do NOT use Teflon tape on non-NPT threads. It cannot be used correctly in this application. Even in the right application, it requires skill not to shread tape or gall metal.

2. Make sure that the leak is not coming from the head, oil pan gasket, rear cam cover, etc.

3. Carefully inspect the sealing boss on the pan, and the flange on the nut. Deep scratches in either will result in dripping, even with new washers. The boss is the more likely culprit. Al is softer than steel. You can also try a little Curil-T as a troubleshooting exercise.
 
i am on hollidays, you know, but in my soon to come shipping to you please remind me of sending you a stretching copper washer for your oil drain plug
these washers have a hollow interior full with an asphaltic compound that allows you to better accomodate any imperfections of the seating surfaces
just by the case tell me your actual washer diameter, i will send everything in two weeks from now
 
Permatex® - High Temperature Thread Sealant
Part Number: 59214
Line: PER

UPC: 79340592148
6 ml Tube
Detailed Description
OEM specified. Locks and seals threaded fittings. Resists leakage, vibration loosening, moisture, hydraulic fluids and diesel fuels. Lubricates threads for easy assembly and disassembly. Won't shred or wear like thread seal tape. Parts may be repositioned up to 4 hours after application. Temperature range from -65F to 400F (-54C to 204C). Contains PTFE.
Suggested Applications: Head bolts into through holes, oil PSI sending units and sensors, oil and coolant lines, fuel fittings, rear axle fill plug, brake and power steering fittings.
 
sfdon said:
Permatex® - High Temperature Thread Sealant
Part Number: 59214
.
Click to expand...

i would not recomend such thing, that is a semi-permanent sealing use, (diff. or gear box, maybe), not for a oil drain plug, use a good washer, one that accomodates the imperfections

the excess of product that comes inside will eventually block something and you will hate it forever

i use washers stuffed with klingerit, and they are very good !
 
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Good suggestions all. I de-greased the lower block/oil pan area and determined the leak was definitely from the plug.

I ended up using Dykem Steel Blue on the oil pan surface where the plug/gasket hits, then used a modified file to deck that surface. It took a couple of tries but finally worked. It really didn't look like there were any scratches or gouges so I'm still not sure what the original problem was.

I also got a copper gasket from NAPA and annealed it with a torch. Finally no leak! Quite the effort for something so simple.
 
My last oil change on the E36 vert, the drain plug came off with an aluminum washer. The aluminum washer was surprisingly soft and likely sealed quite well. Although I didn't try to bend the copper washer, it seemed the aluminum version was quite a bit softer. Suggest using an aluminum washer if you have one handy.

I normally re-use whatever washer is resident on the plug, but this time I used the copper washer. I'm frugal and have a pretty good washer collection. ...
 
I recently bought the sump plug washer from BMW, it was aluminium and seems to work fine. Usually when I do an oil change I get the filter, oil, plug and washer, but due to the cost of the plug I just went for the washer with no plug.
C
 
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