Dumb question, valve cover leak?

[HOBrian]

I have an oil leak that is coming from what I think is the valve cover. The leak is coming from where the aluminum meets the cast iron. (I am right in thinking this is the valve cover, right?) The weather is going to be down right hot on Sat. 50*:-laf I want to try and fix this without going to the dealer. How long and involved is this??



Thanks in advanced!!!

 

[rbattelle]

Technically I believe that's the rocker box rather than the valve cover.

Service manual says you have to "remove the injector harness nuts", and pull the injector electrical plugs.

It also says the gasket is reusable. Are you certain it's not the breather leaking?

Ryan

 

[HOBrian]

It's leaking from the back of the motor. I don't think it could be the breather. It is a little wet at the front but nothing that I would worry about. I am getting drips down on the garage floor on the cardboard I put down. The breather is located in the middle on under the plastic cover, right?

 

[nickleinonen]

the breather is in the middle of the cover, but the draft tube is further back. i will try and find a pic of the location of it

 

[sag2]

My 03 had a rolled seal on the valve cover when it was new. It ran back to the rear of the engine. I just pulled it and rolled the seal into proper position and never leaked another drop. The rocker box seal is similar. Pull it and make sure it is in proper position. Unless it is cut it should seal up just fine.

 

[DPKetchum]

This was discussed many many moons ago. Seems quite a few ozzed oil from the rocker box cover in the rear. Some one that worked for a Cummins shop posted that he had replaced many of these gaskets/seals for same issue. Mine ozzed enough to get all over the bell housing over time. Dealer replaced mine. Not hard to do. Pays . 8 and mine has not ozzed/weeped since and its been maybe 18 months. They saw nothing wrong with old one. I had cleaned mine a couple times over a 2 year prod and finally added some ol dye. That was where it was coming from.

 

[rbattelle]

I've got oil leaking down from high up on the engine, at the back somewhere.

It doesn't leak onto the driveway. It leaks just enough to wet the very back of the block down the sides, especially on the driver side.

On the exhaust side you can see where it makes a little stain beneath the #6 exhaust manifold pipe. That's how I know it's coming from high on the engine.

I'm starting to suspect the valve cover or rocker box gasket, although there is NO oil whatsoever showing on the valve cover or rocker box on the sides at the back of the engine.

It's kind of weird. And why would it suddenly begin leaking after 65k miles?

On edit: anyone know if the valve cover gaskets from Genos include the rocker box gasket as well?

Ryan

 

[rbattelle]

Here's a picture of the relevant parts of the cylinder head. Part number 10 is the rocker box gasket, and number 9 is the valve cover gasket.

DPK - which of these was bad on yours?

The rocker box cover is a piece of cake to remove, but I just noticed the service manual says the install requires guide pins installed at the #1 and #5 bolt hole locations to guide the box into position.

(1) Inspect rocker housing gasket for cuts, nicks,
or tears. Replace if damaged or if gasket has come
out of groove.
(2) Inspect rocker housing gasket for proper installation
in groove. Gasket bead must be centered in
groove. A gasket bead that is tilted to the side will
cause an oil leak.
(3) Install Tool XXXX guide pins (or equivalent)
into the cylinder head at rocker housing bolt locations
#1 and #5.
(4) Install the rocker hoiusing over the guide pins.
Carefully gyide the rocker housing evenly down onto
the cylinder head.
(5) With guide pins in place, install remaining
rocker housing bolts and tighten finger tight.
(6) Remove guide pins and install remaining
rocker housing bolts finger tight.
(7) Install rocker housing and bolts. Torque bolts,
working from center out, to 24 Nm (18ft. lbs. ).
(8) Install injector harness nuts to injector solenoid.
Torque to 1. 5 Nm (13 in. lbs. ).
(9) Connect rocker housing injector harness connections.

I suspect the Geno's part is only the valve cover gasket (number 11).

Ryan

 

[Prairie Dog]

Thats strange, the exploded view is missing the blow-by breather which is what was leaking on my 03. Two hose clamps took care of it.

 

[DPKetchum]

Number 10 is the rocker box gasket. I got a p. m. back then from a tech in a Cummin shop who is on this site but dosen't post much. He said he replaced LOTS of them and they were easy to do. My dealer was like WOW it looks HARD and I said it pays . 8 can't be THAT hard. It wasn't,took tech about that or 1. 0 and it was his first one. No ozz/heavy seep since. I had cleaned mine a couple of times and finally added dye for THEM to black light.

 

[rbattelle]

Hey Brian, if you get a part number for the rocker housing gasket from Cummins, post it for me.

Ryan

 

[HOBrian]

I've got oil leaking down from high up on the engine, at the back somewhere.



It's kind of weird. And why would it suddenly begin leaking after 65k miles?

Ryan

This was my thought also, why NOW does this happen



I have been working on getting my tax stuff together and I hope to get a gift in the mail and I will be able to take a closer look at everything I need this weekend!



Brian

 

[HOBrian]

I just got off the phone with Cummins and they said the part number is 3935878 and the cost is 49. 47.

 

[MMeier]

I've got oil leaking down from high up on the engine, at the back somewhere.



It doesn't leak onto the driveway. It leaks just enough to wet the very back of the block down the sides, especially on the driver side.



On the exhaust side you can see where it makes a little stain beneath the #6 exhaust manifold pipe. That's how I know it's coming from high on the engine.



I'm starting to suspect the valve cover or rocker box gasket, although there is NO oil whatsoever showing on the valve cover or rocker box on the sides at the back of the engine.



It's kind of weird. And why would it suddenly begin leaking after 65k miles?



On edit: anyone know if the valve cover gaskets from Genos include the rocker box gasket as well?



Ryan

I had something similar to this also, turns out it was the O Ring on the oil fill cap leaking on hiway trips. New O Ring cured it, had to pull the plastic POS off first in order to see it though.

 

[JJPage]

Just this past weekend, I was looking over my engine in anticipation of pulling my injectors to send them to Don M. I noticed what I thought might be fuel along the edge where the rocker box meets the head. I thought the injector tubes might be leaking, but after cleaning it up, it did not have an odor like diesel fuel, but more like oil.



I love this site! Already solved my problem before I had to ask!



Thank You!

 

[rbattelle]

I just got off the phone with Cummins and they said the part number is 3935878 and the cost is 49. 47.

Something is wrong. I called Cummins today and they gave me the following information:



Valve cover (part 11 in above diagram): 3954324 @ $36. 15

Rocker box (part 10): 3963379 @ $10. 97



They looked this up using my engine serial number, which is 57018950.



If you put in 3963379 here, you find the description seems correct (rocker lever housing cover gasket).



Checking with Cummins Quickserve, however, 3963379 doesn't come up with anything. Neither does 3935878.



If you search on Quickserve for the rocker box gasket, you find the assembly no problem, but it's not properly broken down into part numbers.



I find it pretty disappointing that Cummins' parts ordering isn't better than this.



If you go to one of the online Dodge parts houses, you can find the rocker box gasket (DC p/n 5101851AA) easily at a cost of about $12, which is consistent with what Cummins quoted me.



I know for certain the valve cover gasket number 3954324 is right (verified in Quickserve and at Geno's, who sells it for $31. xx).



Brian, the local Cummins shop said they have 2 of the rocker gaskets in stock. If you need me to get you the "other one" while I'm there and mail it to you, PM me.



Ryan

 

[HOBrian]

I had not thought they were going to ask for a serial number, so when I called they asked but I just told him it was a 24v 03. That might be where the two numbers are wrong. Mine was not looked up using a vin!

 

[DrDiesel]

Do you change your own oil. Could someone that has change your oil have spilled oil under the rocker box cover, and now it looks like an oil leak. Just a thought.

 

[DerekW]

OKAY THOSE OF YOU WHO HAVE NOT YET FILLED OUT YOUR SIGNATURE ARE WASTING YOUR TIME AND MY TIME ON TDR. I personally got interested in this common occurance but your lack of year model information doesn't get you much help nor does it help the guys who want to learn everything they can about the 3rd gen cummins. I am seriously wondering if it is a early production thing (for instance mainly 2003's) or a common occurance on all cummins engines from 1989 to future engines made in 2999 (provided the cummins is still around with all this emissions bullcrap, why don't we all get togther and pay folks in the EPA to guy blind eye on the cummins for a few years)

 

[rbattelle]

Mine was not looked up using a vin!

Remember - not the VIN, the engine serial number! It's on your engine data plate.

Do you change your own oil. Could someone that has change your oil have spilled oil under the rocker box cover, and now it looks like an oil leak. Just a thought

I do, and have already verified it's not oil traveling back from the fill port. The reason I know is that if it were coming from the fill port, you'd be able to see the oil stains atop the valve cover in the back under the cowling. Oil would have to run that way to get to the back of the engine.

OKAY THOSE OF YOU WHO HAVE NOT YET FILLED OUT YOUR SIGNATURE ARE WASTING YOUR TIME AND MY TIME ON TDR.

Yikes! Relax, Derek. No one's trying to waste anyone's time. Not everyone knows how to fill in a signature.

I have 1 theory on these leaks, and it conveniently explains why both me and HOBrian have suddenly experienced it: cold weather. Over the past month or so it's been very cold here (usually below 20, often below 10 overnight). I suppose it's remotely possible that the shrinkage on a cold engine could open up passages for oil to leak from the valve/rocker gaskets. Maybe. It's a long shot. Wishful thinking.

Brian - before you replace any of the gaskets, try removing the valve cover and simply re-torquing the rocker box bolts.

Ryan