Major oil leak from the rear passenger side

[hgeranium]

My truck has been doing great recently and I’ve had zero problems for a couple of months now. Today I noticed a very strong new type of oil smell. When I got home I looked under the truck to see tons of oil dripping out with a lot of it landing on the exhaust and burning it up causing the smell. I remember I simultaneously had this exact issue when I was having problems with my fuel pressure a few months back but it just went away on its own.
 

I just can’t tell where this oil could be coming from in such large quantities. The pictures won’t do justice of how much oil there is on everything and how fast it was dripping while it was running. 
It’s running so fast it’s making its way all the way to the transmission pan dripping from there as well

^ This picture you can see how much of the exhaust was getting covered and how wide of an area the oil was dripping

Trans pan coated

Here you can see how the oil pan is almost completely enveloped in oil. Same with the starter and the brake lines. The passenger area seems to be where it’s coming from. 

this is what it looks like looking down the engine from the passenger side. Everything is absolutely coated. The driver side is clean.
 

I guess there’s only a few things that could be leaking but with how little room there is back there plus the heat it’s hard to check. 
 

Nothing’s coming from the top of the valve cover because after doing a double gasket on the oil cap, the top is totally dry. PCV and my homebrewed CCV solution are neither puddling nor seeping.

 

Valve cover gasket on the passenger side does look like it’s seeping although I’m a bit skeptical of if it could be responsible for the volume of oil that I’m seeing although there’s no way for me to verify what the very back looks like. Driver side and the front of the VCG are bone dry. When I did my valve cover gasket in 2022 I do remember having a lot of trouble getting the correct torque on the very back bolt with that evil angle. If all my oil was originating up there in the middle back I would expect there to be more even drip on both sides of the engine. I couldn’t get a good picture but the driver side of the engine is clean metal.

 

rear main seal is something I’m really hoping that is not the case, although I truly don’t know how I’d check when so much of the firewall side on this engine is covered in oil and grime

 

I can get more pictures later when it cools down. I was pretty limited laterally with how hot it was down there. I already seared the top of my hand on the exhaust by accident. 
 

what do yall think? I wouldn’t be surprised if there was some crankcase pressure issues exacerbating it because I am still running a bit of a jerryrigged solution for my CCV hose that definitely has more of a restricted flow than the normal hose.
 

Another thing that confuses me is how fast it onset. It suddenly got so bad so quickly. Yesterday there was no smell and zero leaks under the truck, and today it was terrible. there’s certainly always been something leaking in whatever area it is since I’ve had the truck. there’s always been a lot of oil and grime buildup on that part of the engine but it’s never been enough to drip on the ground. I’m guessing it just finally fully failed and is just letting tons of oil out. My oil pressure is still great though FWIW

 

[Eagle_SX4]

It might just be your oil filter adapter. The o-rings are cheap and easy to replace. 

 

 

 

[hgeranium]

5 minutes ago, Eagle_SX4 said:

It might just be your oil filter adapter. The o-rings are cheap and easy to replace. 

 

 

 

I didn’t even think about the adapter. It’s certainly something I’ve never changed and I’ve done at least 3-4 oil changes on the truck lol. Oil change time is coming around quite soon coincidentally. My past oil changed I used T6 Rotella and I can tell it’s freeing a bunch of deposits. I wouldn’t be surprised if it opened back up a failure point in the adapter gasket that was sealed up by gunk.
 

Have you heard of the adapters failing in this way in the past? I suppose it makes sense but I’m just worried with the volume of oil I’m seeing it’s the adapter plus some other things that I’ll be chasing around trying to fix.

[hgeranium]

17 minutes ago, Eagle_SX4 said:

It might just be your oil filter adapter. The o-rings are cheap and easy to replace. 

 

 

 

The bulk of the leak as seen on the ground is definitely coming from the area of the oil filter.  Of course it’s not leaking now that it’s idling but I’m guessing it starts to spray out under pressure and continued driving

The side of the engine close to the oil filter and to the left of the dizzy is soaked and everything to the right of the dizzy is dry. So that also tracks that oil is spraying from the filter and getting blocked by the dizzy from splashing further to the front of the engine. Although oil is certainly seeping from the rear quarter of the VCG, I’m thinking that there’s no way it’s enough to do what the oil filter seems to be capable of. I guess regardless it would be good practice to change the adapter considering I’ve never done it

[hgeranium]

 

For any future viewers of this thread

[watchamakalit]

Degrease the motor at the local car wash, drive it home and inspect for leaks. It will show itself. 

[hgeranium]

I ended up going with a Fel-pro 70301 for the big one. It’s basically impossible to find an AS568 230 o-ring in a kit (that isn’t $100+), so I don’t have a choice but to buy it individually. Less than $4 at autozone so not terrible. I’ve successfully cross-referenced the part number of it with the Mopar one so it’s 100% going to fit 

 

For the other two, I was able to find an o-ring kit that had both a 117 and 219. It was really hard to find one that had both, most of them would either stop right at 116 or 218. Here it is: https://a.co/d/01XeQ4rb

This was the cheapest one I could find because I do not have the money to be spending on the truck right now.  Hopefully this solves my oil issue !

[pizzaman09]

I did the O-rings on mine and it fixed a ton of my passenger side leaks. It's not the easiest or hardest job ever, just some kinda unfortunate to remove bolts.  Lots of work with a box end wrench as there wasn't enough space to back it all the way out with a socket.

[hgeranium]

5 minutes ago, pizzaman09 said:

I did the O-rings on mine and it fixed a ton of my passenger side leaks. It's not the easiest or hardest job ever, just some kinda unfortunate to remove bolts.  Lots of work with a box end wrench as there wasn't enough space to back it all the way out with a socket.

What other bolts do you have to remove? I was under the impression that it was just the one big bolt underneath the oil filter, but maybe that’s specifically for an HO

[AZJeff]

1 hour ago, hgeranium said:

What other bolts do you have to remove? I was under the impression that it was just the one big bolt underneath the oil filter, but maybe that’s specifically for an HO

Just a big special hollow bolt must be removed to dismount the adapter from the block.  They are also VERY TIGHT, typically.
 

The head style changed over the years.  Some were Torx, and some were Allen head.    Don’t use the wrong socket type, or you will probably mess up the bolt and makes its removal doubly hard.

[hgeranium]

40 minutes ago, AZJeff said:

Just a big special hollow bolt must be removed to dismount the adapter from the block.  They are also VERY TIGHT, typically.
 

The head style changed over the years.  Some were Torx, and some were Allen head.    Don’t use the wrong socket type, or you will probably mess up the bolt and makes its removal doubly hard.

Awesome. I'm not entirely sure how I'm going to get a torx to fit on that bolt with a ratchet to go with it if that's the case. Is it possible that I have just a regular hexagonal bolt head? I felt all over the bolt itself earlier to try to see if it was a torx or allen or something but I didn't feel any divot on it. The face of it was smooth. But the bolt itself was definitely hexagonal and I really feel like I can get a wrench on it. The video that I linked showed his being a 3/4" that he got off with a wrench but of course it was an HO. There is a tooooon of gunk all over that area so it's totally possible that it fully filled in the hole where a torx or allen head would be.

 

And I've heard those horrible things about trying to breaking the bolt loose. I also read about a tip to do the job not long after driving it around so the heat of the engine helps loosen things up.

[pizzaman09]

9 hours ago, hgeranium said:

What other bolts do you have to remove? I was under the impression that it was just the one big bolt underneath the oil filter, but maybe that’s specifically for an HO

On my Renix one it is just one large external hex.  It's doable, I personally did it from under the truck.  

[GonzoTheGreat]

Can we talk more about this CCV situation? Is the crankcase able to relieve blowby pressure through its vent on the valve cover, as its supposed to? 

 

If its building excess pressure in the crank, that pressure is gonna want to find a way out. The dipstick tube looks pretty central to the oily mess. Any chance thats whats going on?

[AZJeff]

1 hour ago, pizzaman09 said:

On my Renix one it is just one large external hex.  It's doable, I personally did it from under the truck.  

Yeah, I have heard that some RENIX engines had a plain hex head bolt.  Those are easier to remove since the clearance issues using a Torx or Allen socket are not a factor.

[llhat]

my 89 was on large hex bolt thru the housing.

 

IIRC used a 'kit' from Mahle,      Felpro also has a 'kit'....   I'd watch out for off-brands as the o-ring material can be inferior.

not finding Mahle kits on regular sources ( amazon,  evay )  but fel pro is showing....   leery of some of the others.

heat and time does a number on these....

 

for what it is woth... why not OEM Mopar kit?

 

IF this is where your leak originates...   

[hgeranium]

57 minutes ago, GonzoTheGreat said:

Can we talk more about this CCV situation? Is the crankcase able to relieve blowby pressure through its vent on the valve cover, as its supposed to? 

 

If its building excess pressure in the crank, that pressure is gonna want to find a way out. The dipstick tube looks pretty central to the oily mess. Any chance thats whats going on?

I do have it venting, it’s just not going through the air box to stop it from soaking my air filter for the meantime until I have the time and tools to redo the valve cover gasket and do the valve cover mod at the same time. 
 

Like I said before, I’ve had this issue since I got the truck, even when the original CCV hose was installed. The reason I took it off was that the grommet was so deteriorated that it was letting a lot of oil out onto the valve cover. I had a spare PCV grommet so I just stuck that on there with an old PCV hose and then just routed it towards the ground.
 

I know the diameter of that hose is quite a bit smaller than the CCV hose but I havent seen anything occur as a result that wasn’t already happening before so I think, while it certainly isn’t helping, it’s likely not the main culprit. The only reason I’ve put off just putting on the CCV it’s that I would have to buy an entire new vacuum harness just to break off the hose that I need. I have an HO air box and a capped EGR so my vac routing is very simplified. 

[hgeranium]

1 hour ago, llhat said:

my 89 was on large hex bolt thru the housing.

 

IIRC used a 'kit' from Mahle,      Felpro also has a 'kit'....   I'd watch out for off-brands as the o-ring material can be inferior.

not finding Mahle kits on regular sources ( amazon,  evay )  but fel pro is showing....   leery of some of the others.

heat and time does a number on these....

 

for what it is woth... why not OEM Mopar kit?

 

IF this is where your leak originates...   

Yep that’s a big if for sure. I mean, it has to be the adapter with how the oil spray is positioned. I’ve never heard of a valve cover gasket causing spray of the volume I’m seeing (save for a total catastrophic failure, which is not the case) and it’s almost entirely localized around the area of the oil filter, including the AC hoses around it, the expansion tank, and the side of the distributor cap that’s facing it.

[88towmanche]

I didn't see it mentioned here but I had a sudden massive oil leak on a Cherokee ('88, Renix, 4.0) and it was a failed sending unit - cheap and easy.

 

 

[AnotherOldJeepGuy]

1 hour ago, llhat said:

... for what it is woth... why not OEM Mopar kit?

Most of the time I check with the dealer, and tell them it's a 1990, they just tell me their database no longer goes back that far.  Can you post the OEM Mopar kit part number and where one can get it these days?  1990 4.0 Renix btw, just in case..

[AnotherOldJeepGuy]

Here's a kit at Napa that says it is guaranteed to fit.  Anyone used it?

https://www.napaonline.com/en/p/FPGES72962

[hgeranium]

1 hour ago, AnotherOldJeepGuy said:

Here's a kit at Napa that says it is guaranteed to fit.  Anyone used it?

https://www.napaonline.com/en/p/FPGES72962

Yes that one will fit. That’s the biggest O ring out of three. I cross referenced the part number and it matches up with OEM

[hgeranium]

1 hour ago, AnotherOldJeepGuy said:

Here's a kit at Napa that says it is guaranteed to fit.  Anyone used it?

https://www.napaonline.com/en/p/FPGES72962

Also keep in mind that is just one of three o rings necessary to fully replace them on the OFA. There’s still a medium and a small one that go on that shaft that screws into the block

[hgeranium]

1 hour ago, AnotherOldJeepGuy said:

Most of the time I check with the dealer, and tell them it's a 1990, they just tell me their database no longer goes back that far.  Can you post the OEM Mopar kit part number and where one can get it these days?  1990 4.0 Renix btw, just in case..

87-90 Renix Model O-rings

0.799 x 0.103 AS568 size -117
1.296 x 0.139 AS568 size -219
2.484 x 0.139 AS568 size –230

Dealer Part Numbers for Renix. Sold individually:

33002970, 33002971, 33002972

Renix kit from Crown Automotive-33002970K

91-01 HO Model Orings 

0.676 x 0.070 AS568 size -017
0.859 x 0.139 AS568 size -212
2.484 x 0.139 AS568 size -230
 

From Don himself. Would I ended up doing was buying that fel pro gasket that you found and then an o ring assortment kit that contained both an AS568 117 and 219, for about $13. The big fel pro one is the AS568 230 which is almost impossible to buy individually or as part of an assortment kit. All of the kits that I found stop at 226. 230 is just an uncommonly large size I suppose

 

Edit: sorry for replying three separate times. I knew I could answer the first question and then after a little bit realized I can answer the other one, and then the third question you had lol.

[AnotherOldJeepGuy]

No problem, 3 is far superior to 0!

I am a little confused, the Napa online catalog show this as being 5 gaskets?  Sounds like you believe this items is only 1 gasket not 5?  Am I missing something?

[derf]

5 minutes ago, AnotherOldJeepGuy said:

No problem, 3 is far superior to 0!

I am a little confused, the Napa online catalog show this as being 5 gaskets?  Sounds like you believe this items is only 1 gasket not 5?  Am I missing something?

There are a couple different configurations based on year.  I think this kit has enough to cover the variations with the extras left over.