2007, 5.7, 240K miles. No codes, no issues, no symptoms of any kind except for the oil leak. Truck runs like the day I bought it but it has developed a puzzling oil leak. I apologize if this has been posted, but the search engine kicked out the word "oil". Oil is puddling ON TOP of the intake manifold on the driver's side between the third and last intake port. It then runs down between the manifold and the head then drips onto the exhaust and I have stinky smoke to put up with. Where the oil puddles is between the throttle body and where the fuel inlet line meets the fuel rail and I can't figure out where the oil is coming from. It only leaks under pressure and I didn't think there was any pressurized oil in that area except for beneath the valve cover. I replaced the valve cover gasket, thinking that was the problem, but it was not.

In the photo, the oil is puddling where the screwdriver is pointing, down in the recess between the last two ports. I cleaned it best I could. Maybe it will reveal itself.

 

Almost seems like a bad PCV valve that's causing the pressure to build up & burp out of your vacuum lines. Right where the leak is/above the tip of your screw driver in the pic, is the vacuum hoses for the brake booster and general vacuum lines where they go into the intake for source vacuum. Make sure those hoses are not damaged or brittle.


Either way I'd change the intake gaskets just because Hemi intake gaskets fail to seal after a while and can suck water in causing hydrolock & broken/bent rods, its what kills many Durango hemi engines and why they throw rods commonly, the main difference between that and the Ram is that the Ram has a better cowl design that doesn't allow rain water to drip on the engine as much but even being a better design it still can't prevent water ingestion. Permatex the new intake seals as added protection and get a new pcv valve for around $20 and barring any compression problems or valve seal issues with the engine it should fix the oil leakage. $10 for new intake gaskets and you don't have to remove the ac pump, you can leave it connected but take the mounting bolts off & rest the pump between the water pump & fan shroud area to give enough room for intake installation.

 

Well it was not the PCV valve. I put in a new one but the old one was still good. A little gunky as you might expect, but the check valve still moved freely. Any other suggestions?

 

That's good that you've got a new one. See the thing with pcv valves is that they have a spring in them and that spring loses its tension over time, which is why its always a good idea to buy a new one instead of cleaning one. I'd change pcv valves every year on my Neon and it always cleared up crankcase venting issues. They fight both pressure and vacuum and if that spring is weakened its not going to work as intended. No offense to anyone but I usually end up rolling my eyes at the thought of cleaning a pcv valve in favor of replacing them.

So on the back of that, did you check the vacuum lines that go into the intake manifold at the throttle body base for leaking?

If I were you I'd do a simple vacuum test and then if its dodgy do a compression test to rule out possible blow by that could cause excessive crank case pressure & leaks, then if it checks out good I'd replace the intake manifold gaskets, which is always a good idea to do on a Hemi with a plastic intake manifold, combats potential hydrolocking, because after a even a few years these rubber gaskets fail to seal in certain weather conditions and with the flat mounting of the intake manifold to the heads water can pool and be sucked in, happens on all stock Hemi engines with a plastic intake, just as all Magnum V6, 318 & 360 V8 engines will suffer a failed plenum gasket with little to no obvious symptoms.

If you say the truck still runs fine then I'd say you need to replace the intake gaskets and that crankcase pressure leaks caused by blowby is not the problem. It is also possible that maybe whoever put oil in the engine last spilled it over the intake by accident? That happened to me yesterday when the wind blew my oil bottle over, but only a little spilled onto the intake.

Either way if I were you, I'd replace the intake gaskets no matter what and add permatex to the gaskets to make sure future fails don't happen and that I won't have to worry about hydrolocking.


You also could have bad exhaust valve seals, and whatever is damp on the intake manifold is unrelated to the smell.

 

Actually I just realized your truck is a 07 Hemi. Which most likely has MDS (Multi Cylinder Deactivation) It has 4 servos that control oil flow to your lifters to shut cylinders off and right where you described your leak is exactly where one of the servos is under the intake manifold. It is VERY possible that servo's seal is leaking, even if you don't have mds the servo plug is still there and could leak. In any case your intake manifold will have to come off to fix that. Its not too bad to do, hour off and an hour on, hardest part is cleaning the intake.

 

Thanks Josh. That's a great photo you attached. My truck does have MDS. Where the oil is puddling on the manifold is directly above the "J" shown in the photo (just below the red circle). If that servo is leaking oil and it can get out the rear and run down the side of the head, that could very well be the leak. Won't explain how oil gets on top of the manifold though. I guess next warm break in the weather, the manifold is coming off.

Any idea what type of seal is on the servo? Is is an O-ring?

 

I'd imagine its an o-ring style seal. When you take the intake off, put new intake gaskets in and add some copper permatex to where they seat into the intake so that when it is tightened it will form an extra seal on the intake taking up slack for the o-ring style intake gaskets, this way you're covered if the engine gets wet you won't have to worry about hydrolock and a rod bending.

Tighten the intake in a two step process, since its plastic you want to lightly torque it by hand in the correct sequence and then check them a second time to make sure the intake seated.


The oil on top of the intake could have been accidently spilled, happened to me a few times, some of the synthetic containers have an odd shape to them and like to fall over mid pour. As I stated before the only thing in that area is the vacuum lines and fuel rail. Did you take it in for an oil change? or do you do your own?

 

No, I always change the oil. The filler spout is way up in front of of where the oil is collecting and the way the manifold is molded, it would be nearly impossible for spilled oil to migrate to the back of the manifold. The oil I'm seeing is the same color as what's on the dipstick. I stopped by the dealer today and talked with the parts guy. His diagram didn't show the seals for the servo (he called it a solenoid) but he showed me a new servo and it has three blue O-rings on it - each a different size. New servo is about $65 from dealer but I imagine I can find the O-rings.

Of the two vacuum lines on that side, the large rubber one goes to the brake booster, the other, smaller plastic one goes directly to the small emissions canister, through it and back to the fuel inlet. Neither makes a fork or joins any other vacuum line. The dark area on the small one in my photo is where I sprayed cleaner on it.

I'm definitely going to dig into the manifold but it's going to have to wait until the East Coast thaws out a little. I'll repost with results when I get a chance to look into it.

Thanks.

 

Maybe its just the royal purple & mobile synthetic bottles that fall over on me, I've had a few tip over and spill all the way down the drivers side of the intake, it'll probably happen to you now that I've mentioned it lol.


I'm sure you'll get it figured out. Also make sure you permatex those new intake gaskets! Some people on this forum have called me high for doing this, but you'll thank me when your 0-ring gaskets shrink on a cold day and fail to seal and your engine doesn't ingest water & hydrolock & break a rod because the permatex is actually sealed to the intake & heads. You don't need a ton but enough so that the permatex won't leak into the ports or injector when you torque the manifold, you won't the intake side of the gasket to have a nice coat of perm on it so that water can not get in anywhere! actually permatex by itself is a better gasket than these O-rings but you need the O-rings to take their place in the intake.


You may think that you're just fixing your oil leak by taking the intake off and changing the servo o-rings, but the new intake gaskets & bead of perm on each port IS the most important fix you'll be doing, the failure of o-ring gaskets alone to improperly seal an intake manifold have killed far too many Hemi Durangos and a handful of Rams. This is the real reason why those big plastic engine shields started being put over the top of Hemi engines.

 

I have the same problem. Do you find out what was the problem? Thanks