16 RAM 3.6 oil leak

[Nickmigues12]

Hi all, back again with another issue on my RAM (still haven’t resolved my 3 way valve issue but that’s for another day at this point lol. As stated in the title it’s a 16 with the 3.6, and I have 198k on it. I have an oil leak, and having a hard time pinning it down- I fear it’s the rear main seal. I know what you’re all thinking- oil filter housing- but it’s been replaced with an aluminum one a few years back, the back of the block is dry and one of the other tell tale signs I’ve noticed in the past (I’ve fixed this leak more than once in the past on my truck and other trucks) is that typically the trans lines that run under the bell housing are typically wet as well as the transmission pan, which is all dry. Also had new valve cover gaskets put in earlier this year when I was replacing some rocker arms. Only place that has any oil is where the trans meets the engine, the dust plugs and of course it’s all over the oil pan and block in that area. So I’m curious what anyone else’s experience is- anyone ever actually had a rear main go bad on these? Or do they have one of those stupid upper oil pans that could be leaking in the back? Could the actual oil pan be leaking and somehow throwing oil upwards? Going to do some deeper investigation tomorrow or later this week when I have time, this was just a quick observation I made today but always love to get ideas from knowledgeable people on forums! Thanks.

 

[SitKneelBend]

Hi all, back again with another issue on my RAM (still haven’t resolved my 3 way valve issue but that’s for another day at this point lol. As stated in the title it’s a 16 with the 3.6, and I have 198k on it. I have an oil leak, and having a hard time pinning it down- I fear it’s the rear main seal. I know what you’re all thinking- oil filter housing- but it’s been replaced with an aluminum one a few years back, the back of the block is dry and one of the other tell tale signs I’ve noticed in the past (I’ve fixed this leak more than once in the past on my truck and other trucks) is that typically the trans lines that run under the bell housing are typically wet as well as the transmission pan, which is all dry. Also had new valve cover gaskets put in earlier this year when I was replacing some rocker arms. Only place that has any oil is where the trans meets the engine, the dust plugs and of course it’s all over the oil pan and block in that area. So I’m curious what anyone else’s experience is- anyone ever actually had a rear main go bad on these? Or do they have one of those stupid upper oil pans that could be leaking in the back? Could the actual oil pan be leaking and somehow throwing oil upwards? Going to do some deeper investigation tomorrow or later this week when I have time, this was just a quick observation I made today but always love to get ideas from knowledgeable people on forums! Thanks.

I have had something leaking oil replaced by dealer under warranty but I'm forgetting the details at the moment. I'll post the service notes when I find it.

Quick question, have you inspected the PCV valve for leaks? It's back there too

 

[Nickmigues12]

I have had something leaking oil replaced by dealer under warranty but I'm forgetting the details at the moment. I'll post the service notes when I find it.

Quick question, have you inspected the PCV valve for leaks? It's back there too

I looked up there and don’t see any evidence of a leak coming from that area, can actually get a surprisingly good look at the back of the engine from under the truck. I’d love to have a warranty repair but I think 198K miles is a little out of the warranty at this point lol. But I’m a mechanic anyways so I can get it fixed I just don’t wanna do a rear main seal lol. Tomorrow when I’m under it trying to find the issue I’ll take some good pictures of what I’ve got too, if for nothing else future reference for others

 

[SitKneelBend]

I looked up there and don’t see any evidence of a leak coming from that area, can actually get a surprisingly good look at the back of the engine from under the truck. I’d love to have a warranty repair but I think 198K miles is a little out of the warranty at this point lol. But I’m a mechanic anyways so I can get it fixed I just don’t wanna do a rear main seal lol. Tomorrow when I’m under it trying to find the issue I’ll take some good pictures of what I’ve got too, if for nothing else future reference for others

I'll dig up the paperwork. I had a very similar issue which I thought was the oil cooler but they diagnosed and fixed something else. If I remember right the service notes said something like "blowing oil everywhere"...

 

[SitKneelBend]

I looked up there and don’t see any evidence of a leak coming from that area, can actually get a surprisingly good look at the back of the engine from under the truck. I’d love to have a warranty repair but I think 198K miles is a little out of the warranty at this point lol. But I’m a mechanic anyways so I can get it fixed I just don’t wanna do a rear main seal lol. Tomorrow when I’m under it trying to find the issue I’ll take some good pictures of what I’ve got too, if for nothing else future reference for others

Here you go ...

 

[Nickmigues12]

Here you go ...

View attachment 556129

Ah yeah, that’s the valve cover gaskets, which I have also done this year and are dry this time around as well

 

[SitKneelBend]

Ah yeah, that’s the valve cover gaskets, which I have also done this year and are dry this time around as well

No worries, is there a reason you don't expect the oil cooler? The housing might be sturdier now and won't crack, but I think I've heard of some failures coming from the gaskets on the mounting surface. How does your oil look? Did you inspect the valley?

 

[Daw14]

Start with a complete engine degreaser , this should make it easier to locate the leak.
Whole lot nicer when it is time to fix that leak also, if you are not doing the job yourself , your mechanic will appreciate it.

 

[Nickmigues12]

No worries, is there a reason you don't expect the oil cooler? The housing might be sturdier now and won't crack, but I think I've heard of some failures coming from the gaskets on the mounting surface. How does your oil look? Did you inspect the valley?

The reason I don’t suspect it is because I’ve dealt with the leak more than once, and so I’ve learned the pattern it develops which it leaks off the trans lines and the trans itself, which are all dry this time around. I’m not ruling it out completely and I will check the valley of the intake as well to make sure but I’m feeling confident it’s not the issue. Oil was about a quart low actually when I checked it yesterday, so it’s a decent leak but not sure how long it’s been leaking either. Going out to work on the truck now so I’ll snap some pics and dig into it and see what I can figure out

 

[Nickmigues12]

Now that I’ve gotten in there I’m thinking/hoping it’s an oil pan gasket. I couldn’t get a good pic but the back of the engine is definitely dry, and the valley is dry as well. I pulled the dust plugs out as well and inside of that area looked clean and dry as well, so it’s just getting on the plugs from somewhere else. I scraped all the dirt off and cleaned up the oil and let it run and couldn’t find a leak yet, so I’m gonna drive it around over the next day or 2 and check it out as I go and see what it’s looking like but I’m thinking oil pan gasket.

 

[Atcer2018]

View attachment 556153
Now that I’ve gotten in there I’m thinking/hoping it’s an oil pan gasket. I couldn’t get a good pic but the back of the engine is definitely dry, and the valley is dry as well. I pulled the dust plugs out as well and inside of that area looked clean and dry as well, so it’s just getting on the plugs from somewhere else. I scraped all the dirt off and cleaned up the oil and let it run and couldn’t find a leak yet, so I’m gonna drive it around over the next day or 2 and check it out as I go and see what it’s looking like but I’m thinking oil pan gasket.

Admittedly my knowledge and experience with the 3.6 is limited but it appears from your pic that there is a good bit of oily grime pretty far up above the oil pan. Not sure how the oil migrated upwards so far. Does the 3.6 have a two piece oil sump? If it does would make more sense that it’s the upper gasket.

 

[Nickmigues12]

Admittedly my knowledge and experience with the 3.6 is limited but it appears from your pic that there is a good bit of oily grime pretty far up above the oil pan. Not sure how the oil migrated upwards so far. Does the 3.6 have a two piece oil sump? If it does would make more sense that it’s the upper gasket.

I believe it does. I’ve been watching it this week and it’s barely gotten wet again, so I’m wondering if it’s a fairly slow leak that I just never noticed and it got caked up there over a long period of time, especially since I recently did about a 2,000 mile trip in the truck and drove a bit on dirt roads. Whenever I have time I think I’m gonna just replace the lower pan gasket and see what it does, but I am wondering (and hoping its
Not) if the upper pan is leaking a little too.

 

[Nickmigues12]

Update, resealed the oil pan gasket- it uses silicone despite the fact that you can buy an actual gasket for it- about a week ago and it’s doing good so far, no signs of leakage again. In the process I did discover quite the issue tho- I found a piece of timing chain guide wedged into the oil pickup tube.. luckily I don’t think it caused any oil starvation issues or anything as oil still had plenty of room to go around the piece but now of course I gotta look into doing the guides, and ill probably replace the chain since I’ll be in there anyways and by the time I get to it it will have 200K on it. Oddly enough I don’t have any chain noises or anything so I have no idea how long that piece has been broken off either. About to park the truck until spring anyways so that’s when I’ll get to it but poor truck just seems to be adding to the list of issues as it gets up there in age lol.

 

[SitKneelBend]

Update, resealed the oil pan gasket- it uses silicone despite the fact that you can buy an actual gasket for it- about a week ago and it’s doing good so far, no signs of leakage again. In the process I did discover quite the issue tho- I found a piece of timing chain guide wedged into the oil pickup tube.. luckily I don’t think it caused any oil starvation issues or anything as oil still had plenty of room to go around the piece but now of course I gotta look into doing the guides, and ill probably replace the chain since I’ll be in there anyways and by the time I get to it it will have 200K on it. Oddly enough I don’t have any chain noises or anything so I have no idea how long that piece has been broken off either. About to park the truck until spring anyways so that’s when I’ll get to it but poor truck just seems to be adding to the list of issues as it gets up there in age lol.

That's a lucky find! Glad you got the first issue squared away too!