Oil pan drain plug

[Mikey1989]

Had my truck up on a lift over the weekend. One of the things I was inspecting was the source of a very slow oil leak. More like a slow drip, but enough so I can't park it anywhere nice without leaving a mark. While there was a little tiny bit of oily stuff on the transfer case, it looks like it might be dripping from the oil pan drain plug. 

 

I have heard of so-called "crush washers". Copper or aluminum, one time use? Or what about a rubber material?

What do you think?

 

[Eagle_SX4]

I worked at a quick lube shop for a while. The aluminum and copper crush washers do work but it is difficult to remove them once they get smashed in to the threads of the drain plug. I usually use a fiber gasket. Most auto-parts stores should have some. I have even found that some hardware stores have them as well.

[Pete M]

be sure to check for oil coming down the back of the engine from the valve cover gasket too.

[eaglescout526]

I don’t even think our drain plugs need such though. I recall the catalog just showing the plug. 

[Eagle_SX4]

5 minutes ago, eaglescout526 said:

I don’t even think our drain plugs need such though. I recall the catalog just showing the plug. 

With out a gasket it will leak for sure. The plug listed in the catalog probably comes with a new gasket. 

[Mikey1989]

There is also a ton of oil residue on the oil pan, lower engine block, transmission housing, cross pieces, ugh. The position of the oil filter makes me wonder if all this mess is due to the filter changes. Thinking I'm going to get under there and clean it all up.

I like the fiber gasket idea, had thought about that, so nice to hear @Eagle_SX4 experience. Also appreciate the advice to suspect the valve gasket, another reason to clean all that up and see what happens. Hopefully it is just a matter of doing my own oil changes from now on to avoid further spills. That, and geez, oil change inflation is killer these days.

[llhat]

found a 100 pack of aluminum ones on the evil bay for just a few bux,  were in mailbox today.

think my 94 GGC with 5.2 had a 'nylon' sealing washer.

[AZJeff]

Current factory Mopar branded oil drain plugs have a polymer washer that is molded on to the flange head of the drain plug bolt.

 

Dorman makes an equivalent, and is available from Oreilly auto parts.

 

Drain Plug

[AnotherOldJeepGuy]

On 4/15/2025 at 11:12 AM, Mikey1989 said:

Hopefully it is just a matter of doing my own oil changes from now on to avoid further spills

My 2 cents for what it's worth.  I punch a hole in the top of the old filter to release the vacuum and let more oil out before removing it.  I use a nail rather than a drill since I think the drill might leave shavings where the nail is just a flared out puncture.

Edited April 16, 2025 by AnotherOldJeepGuy
grammer and typos

[Mikey1989]

20 hours ago, AnotherOldJeepGuy said:

My 2 cents for what it's worth.  I punch a hole in the top of the old filter to release the vacuum and let more oil out before removing it.  I use a nail rather than a drill since I think the drill might leave shavings where the nail is just a flared out puncture.

I'm on it, great idea. Plus I can let it drain out for a good while, no hurry to unscrew the thing. It's gonna be a chore to clean up 36 years of oil and road crap off the thing. 

[Mikey1989]

22 hours ago, AZJeff said:

Current factory Mopar branded oil drain plugs have a polymer washer that is molded on to the flange head of the drain plug bolt.

 

Dorman makes an equivalent, and is available from Oreilly auto parts.

 

Drain Plug

Another great idea - I'll do this. Thank you.

[Mikey1989]

I love this forum, it gives me such confidence I can DIY so much of what I used pay somebody to do. Now I'm entering retirement maintaining cash flow is getting more and more worrisome.

[AZJeff]

I am retired, and I know about cash flow.  I had a machine shop redo the short block on my MJ, which had budgeted for.  
 

However, that interrupted over the past 12 months by unexpected heart surgery due an infected heart valve.😳

[AnotherOldJeepGuy]

12 minutes ago, AZJeff said:

However, that interrupted over the past 12 months by unexpected heart surgery due an infected heart valve

Yikes!  I hope all is well now.

[watchamakalit]

7 hours ago, Mikey1989 said:

I'm on it, great idea. Plus I can let it drain out for a good while, no hurry to unscrew the thing. It's gonna be a chore to clean up 36 years of oil and road crap off the thing. 

Parts store degreaser and the coin operated car wash are the way to go. Might take a couple treatments depending on the amount of crude built up. But in the end with some patience and a bunch of quarters they will all clean up nicely.

[AnotherOldJeepGuy]

17 hours ago, watchamakalit said:

Parts store degreaser and the coin operated car wash are the way to go

I have used about 4 cans and one spray bottle of GUNK Engine Degreaser over the last several months and there is still a fair amount of crap!  The degreaser warns of getting it on electrical connections although it doesn't elaborate on what ones are and are not an issue.  To this point I have been crimping aluminum foil over stuff in the area I am spraying, curious what everyone else does.

[89 MJ]

I use oil eater for my engine degreaser. Works better than anything else I’ve ever used and is better for the planet than lots of other ones. I’ve used this stuff and a pressure washer in my engine compartment several times with no issues. The only thing I had to soak multiple times with this stuff was my tractor because the grease and dirt was hardened and an inch thick in places. 

[AnotherOldJeepGuy]

Does oil eater have the same warning to cover electricals first?

[89 MJ]

18 minutes ago, AnotherOldJeepGuy said:

Does oil eater have the same warning to cover electricals first?

Not sure, but I’ve never covered electrical stuff and been fine. I just try to keep the pressure washer from hitting most of the connectors directly. 

[AnotherOldJeepGuy]

4 hours ago, 89 MJ said:

I just try to keep the pressure washer from hitting most of the connectors directly

Makes sense.  I will look for some Oil Eater and give that a try.  We do have a couple coin washers in the vicinity still.

[watchamakalit]

I recommend the coin wash because it can leave quite the oily residue. You probably won't want it in your driveway