Trying to figure out if I have two oil leaks or an oil and transmission leak on my 73 Duster 318

[tonyp25]

So I’ve been meaning to tackle this for awhile but I’m having trouble figuring out the second leak. I know the one leak is coming from a poorly done piggyback oil drain plug. I’ve had the car less than a year and noticed that the drain plug is halfway out and won’t tighten. So I’ve bought a new one. Here’s to hoping they didn’t JB weld it on.

The second leak seems to be near the transmission but it sure looks, smells and feels like oil. There seems to be a bit of space/gap (circled in red below) where the liquid is coming from and then dripping from the low point (circled in yellow). Any ideas?

The oil and transmission fluid levels are fine. And both very clean. The drips maybe make a dime size drop once a day. For how clean the trans fluid is I’d expect it to be red on the ground but who knows how much oil it mixes with on the cars body from the first leak.

I’d imagine the right way to do this is really clean everything down and try to actually find where the leak is coming from or use a dye. Was hoping for best guesses first.

 

[OldmanRick]

For the second leak i'd start looking up higher. Could be the intake, oil sending unit or the dizzy. If not, might be a rear main. How many miles are on that engine.

 

[TrailBeast]

So I’ve been meaning to tackle this for awhile but I’m having trouble figuring out the second leak. I know the one leak is coming from a poorly done piggyback oil drain plug. I’ve had the car less than a year and noticed that the drain plug is halfway out and won’t tighten. So I’ve bought a new one. Here’s to hoping they didn’t JB weld it on.

The second leak seems to be near the transmission but it sure looks, smells and feels like oil. There seems to be a bit of space/gap (circled in red below) where the liquid is coming from and then dripping from the low point (circled in yellow). Any ideas?

The oil and transmission fluid levels are fine. And both very clean. The drips maybe make a dime size drop once a day. For how clean the trans fluid is I’d expect it to be red on the ground but who knows how much oil it mixes with on the cars body from the first leak.

I’d imagine the right way to do this is really clean everything down and try to actually find where the leak is coming from or use a dye. Was hoping for best guesses first.

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First thought is that it has a rear main seal leak.
So far no indication of the trans leaking.
Of course it’s possible the leak is actually higher up, like a manifold leak, or valve cover, or even an oil sender.

Get ready to have people telling you to tear everything apart and rebuild it.

Clean it up and verify first,
but that sure looks like classic rear main leak.

Oldmanrick posted about the same.

 

[CFD244]

That's an old "plug in a plug" usually installed by the quick lube places when dealing with a stripped out pan. There is a gasket on the big part that self taps into the pan and has a gasket (and stays there). The small part has a pipe thread.........Put some teflon tape on the small plug when you change your oil, and make sure that you use a larger wrench on the big lug when you loosen and tighten the smaller plug........Or fix it properly

 

[tonyp25]

That's an old "plug in a plug" usually installed by the quick lube places when dealing with a stripped out pan. There is a gasket on the big part that self taps into the pan and has a gasket (and stays there). The small part has a pipe thread.........Put some teflon tape on the small plug when you change your oil, and make sure that you use a larger wrench on the big lug when you loosen and tighten the smaller plug........Or fix it properly

Shouldn’t that small part be able to thread all the way in? It’s leaking down those threads but I tried to tighten by hand and can’t get it to budge.

The right way would be either to re-thread the oil pan or just buy a new pan, right?

 

[tonyp25]

First thought is that it has a rear main seal leak.
So far no indication of the trans leaking.
Of course it’s possible the leak is actually higher up, like a manifold leak, or valve cover, or even an oil sender.

Get ready to have people telling you to tear everything apart and rebuild it.

Clean it up and verify first,
but that sure looks like classic rear main leak.

Oldmanrick posted about the same.

Thanks for the input! Very true about it being higher up. Let me fix the drain plug first and clean down the engine. The rear main seal seems like it could be it and I’d rather it be that than a trans leak. I won’t be tearing the whole car apart haha I mean if it doesn’t leak a little bit of oil is it a mopar? It’s free rust prevention.

I’ve had decent luck with AT-205 reseal as engine oil additive too so maybe I’ll try that first.

 

[DartDave73]

If you have a pressure washer, spray it down. Top to bottom. Anywhere you see oil. Engine degreaser first will also help. Then run it and check it again later. There's too much oil all over on your pictures to determine what is going on. Pull that inspection cover on that trans and clean inside too.

If after all this you still can't figure out where it's coming from, you'll have to start moving things out of the way to see where it's coming from. Might be something simple as an expansion plug on the back of the block. If it was me, I'd remove the trans to get a better look at it. Chances are you'll have to remove it anyway to make any repairs, so might as well get that hunk of metal out of the way.

 

[413]

Castrol super clean and a pressure washer. Then you can see what up. Either from top, or oil pan or rear main.

Your drain plug is a lug nut and a bolt. And it’s most likely leaking through the bolt threads. It looks like 1/2”x20. Hold the bolt head and loosen the lug nut, then unscrew the bolt. It’s the old backyard fix.

 

[CFD244]

Castrol super clean and a pressure washer. Then you can see what up. Either from top, or oil pan or rear main.

Your drain plug is a lug nut and a bolt. And it’s most likely leaking through the bolt threads. It looks like 1/2”x20. Hold the bolt head and loosen the lug nut, then unscrew the bolt. It’s the old backyard fix.

I believe this is what he has........I installed lots of them when I worked in a lube shop back in the 80's. Never heard of the lug nut fix....But I've been wrong before

 

[Demonracer]

The very first thing I would do, would be to do a thorough clean up, after that I'd start looking for the leaks. With everything coated as it is, you'll be chasing your tail trying to find them.

 

[tonyp25]

I believe this is what he has........I installed lots of them when I worked in a lube shop back in the 80's. Never heard of the lug nut fix....But I've been wrong before

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That’s it.

I haven’t taken it off yet but picked up the below bolts that all say they fit the Duster.

From left to right we have a standard, piggyback, single oversized with magnet and double oversized. Not sure which one to use yet.

 

[tonyp25]

Also I was thinking of using thread sealer or JB weld on the large bolt of the piggyback plug that initially goes into the threads and then using Teflon tape on the small bolt that goes in. This would just be temporary until I replace the pan.

 

[CFD244]

Also thread sealer or JI was thinking of usingB weld on the large bolt of the piggyback plug that initially goes into the threads and then using Teflon tape on the small bolt that goes in. This would just be temporary until I replace the pan.

For the time being, use the piggy back one. Thread the big part in with a good gasket and leave it there (the more you work whats left of threads in the pan, the more likely they will fail). Use the small pipe thread plug for the repetitive draining with a little teflon tape wrapped around the threads (in the right direction of course). This will get you by until you get the pan repaired.

I wouldn't use JB on the big part. The gasket should suffice.

Another type of fix..........Find a metric plug SLIGHTLY larger than your stripped out pan. Drill and tap to this size.......Will save you a pan replacement. I did this on my '87 Ram and it's still there today. Don't go too big or you'll ruin the thick metal inside the pan that takes the threads.

Good Luck

 

[tonyp25]

For the time being, use the piggy back one. Thread the big part in with a good gasket and leave it there (the more you work whats left of threads in the pan, the more likely they will fail). Use the small pipe thread plug for the repetitive draining with a little teflon tape wrapped around the threads (in the right direction of course). This will get you by until you get the pan repaired.

I wouldn't use JB on the big part. The gasket should suffice.

Another type of fix..........Find a metric plug SLIGHTLY larger than your stripped out pan. Drill and tap to this size.......Will save you a pan replacement. I did this on my '87 Ram and it's still there today. Don't go too big or you'll ruin the thick metal inside the pan that takes the threads.

Good Luck

Thanks for the info!

The new piggyback is a double oversized bolt where the old one I took off was only single oversized. Any idea if these oversized bolts are supposed to be self tapping or would I need to drill and tap anyways just to get this slightly larger piggyback to fit?

 

[CFD244]

Thanks for the info!

The new piggyback is a double oversized bolt where the old one I took off was only single oversized. Any idea if these oversized bolts are supposed to be self tapping or would I need to drill and tap anyways just to get this slightly larger piggyback to fit?

The piggy back ones that I used were self tapping. Only go 2nd oversize if the first oversize strips out. Is the one currently in the pan now stripped?

BTW, if you are putting in a larger self tapper, make sure that it goes in straight.

 

[mgoblue9798]

Few ideas for you. Fix the known leak. Clean and pressure wash. If you still have a leak and cannot tell if oil vs trans fluid get some fluorescent dye and add to your oil. Start looking for the source at the top of the engine working your way down to the highest part you see oil leaking. Leak will likely be at or above that point.