Thread: V8 valley cover oil leak

Give the engine a clean and take the flame trap/pcv filter off. That will at least confirm or eliminate the standard version of valley cover oil leak. ( Flame trap gums up and blowby pressurizes the crankcase and blows oil mist out everywhere it can).

Whether or not another valley cover/gasket is needed is unknown.

Of course it could be a leaking rocker cover gasket as well. If you can track the oil leak, it will give you a better idea on what may be a bigger problem.

Quite possibly the rocker cover gaskets, if it still has the rubber type gaskets, then even if they are tight they can still leak like a seive. A bit of a pain to change but easier than the valley etc.

JC

Thanks guys. I figure it is the rocker cover gaskets too. Was just putting it out there to see if there was something I hadn't thought of.

I replaced both rocker cover gaskets when I did the valley etc last time. I used the rubber ones.

JC it is interesting to hear you say that the rubber ones are no good as I used them last time due to hearing that they were the way to go.
I had changed the driver's side gasket once earlier (with rubber one) and when I did them again with the other work it had split along its length and was leaking so I am already dubious of their all round goodness.
What do you use/recommend?

I have cleaned the PCV steel wool/mesh thing before. Will clean it again when I redo the tappet cover gaskets. Didn't think of that pressurising the joints so thanks for that.

Thanks

Originally Posted by Utemad

Thanks guys. I figure it is the rocker cover gaskets too. Was just putting it out there to see if there was something I hadn't thought of.

I replaced both rocker cover gaskets when I did the valley etc last time. I used the rubber ones.

JC it is interesting to hear you say that the rubber ones are no good as I used them last time due to hearing that they were the way to go.
I had changed the driver's side gasket once earlier (with rubber one) and when I did them again with the other work it had split along its length and was leaking so I am already dubious of their all round goodness.
What do you use/recommend?

I have cleaned the PCV steel wool/mesh thing before. Will clean it again when I redo the tappet cover gaskets. Didn't think of that pressurising the joints so thanks for that.

Thanks

Sorry, I meant they ARE the best ones (The ones with the metal inserts in the bolt holes, as per OEM) until they go hard, and then due to the metal inserts you can't tighten them up any further. These are all I use now.

JC

Thanks JC. I did use the rubber ones with the metal bolt hole bits.

Do you silicone them on to the head?
I'm thinking of doing so this time around.

Originally Posted by Utemad

Thanks JC. I did use the rubber ones with the metal bolt hole bits.

Do you silicone them on to the head?
I'm thinking of doing so this time around.

No sealant required, I find I just sit them on the top of the head and jiggle the rocker cover around until the holes line up, make sure the edges are outside the cover and bolt em down tight

JC

Check the rocker cover bolts. They loosen and allow the gaskets to leak. The bolts are standard 12-point heads but trying to find a 12-point socket in 1/4" drive is a little difficult. I borrow one from my local LR workshop.

Alrighty then. Just finished slashing the back of my right arm on some zip ties that weren't properly trimmed. Oh what fun.

While I was doing that I removed all the 12 point bolts and replaced them with allen key bolts. Socket head screws I think they called them. The same type that are holding your plenum cover lid on but smaller.
Those factory bolts annoyed me once too often.
They are 1/4in UNC. One lot were just under 1in long and the other lot were 1 1/2in long.
I glued washers under the heads with one of the Loctite glues.
Didn't remove the tappet cover gaskets as they seemed pliable going by the protruding edge/lip and they are only a couple of years old so I hope they are still ok.

I also cleaned the steel sponge mesh in the PCV/fire trap thing again. It was thick with oil in the mesh (not gungy but fresh stuff) so I don't know if it is meant to be like that or if it was clogged. The hose that came off it that goes to the air intake was clean. Either way the mesh is clean now.

Ron I have the 12 point socket in 5/16 3/8 drive. 1/4in would be better but wasn't available at the shop when I bought it. Quite happy that I no longer need it for this job though.