Purpose of baffle inside valve cover?
 

Recently discovered (yep, overlooked previously) that on the top of the inside of the valve cover on my '85 300CD-T (617.952 w/trap oxidizer, Calif. veh.) there is a kind of metal baffle that runs most of the length of the cover.

First, does anyone know why this is there? My '83 300CD-T (617.952) doesn't have this:confused:
Second, it concerned me a bit that on the end of the baffle that has a metal cover, it seems to be sealed with a (by now) hardened black rubber gasket-like material. Is this a risk to the engine should some of it ever come loose?
Curiously, the other end of the baffle is open, uncovered.

I'm guessing this arrangement has something to do with emissions. Anyone know for sure?

Thanks for the help:)

It helps reduce the amount of oil that gets blown into the breather hose that goes to the air cleaner and then back to the pan. If you do a search you should find info on it and resealing it with epoxy. Also do a search on your trap and see what you can do with that.

I dont have this baffle. I dont have a drain for blowby back into my oil pan either. It was plugged off so water can't get in during high creek/river crossings, which is a good thing.

I do get quite a messy engine from oil though that just floats out the hose from the valve cover.

Would it be to my advantage to snag one of the valve covers with the baffle in it if I ever come across one?

Thanks, jerryb:)

Sorry I don't have any help for you, coachgeo:confused:

coachgeo,

I would expect the baffle to reduce the size and quantity of oil droplets making it into your intake. The baffle forces the blow-by gasses to change direction a few times on their way out. This leaves them in liquid form on the walls of the baffle where they join other droplets that failed to escape, and eventually they collect until they are full size drops which run down and drip back onto the valve gear. Good luck, Jim

Thanks.. sounds like this could be to my advantage. Is this in CA spec cars only?

I want to keep my eyes open for a cover of this type.

coachgeo,

Actually, I have never seen one without the baffles. I think they are removable, but I can't think of a good reason why someone would take them out.

I routinely rinse the thing with gasoline when I take the valve cover off, then let it dry good in the sun while I adjust the valves. I think I am wasting gas when I do it but I am unable to put an oily, black thing back on the engine when the time comes, so I clean it good.

Any junk yard should be able to cough up a valve cover. Let us know if you find one without the baffles (but is ok if you stop looking after you find one with them). Good luck, Jim

can someone post a inside picture of the valve cover? Maybe I have one w/baffles and I'm just thinking these baffles would be bigger. Had the valve cover off a month ago but dont recall anything in it that would make me think "baffles"

It looks like a piece of steel (blackish and about 2" X 2", can't really tell what's inside it) that runs almost the length of the driver's side of the cover. I don't have a picture but that's what I remember, I thought it was riveted on somehow but I'm not sure. I don't think it was real easy to remove or maybe it looked like it would be hard to put back on because I'm one of those people that has to have everything perfectly clean before I put it back together..... and I didn't take it off to clean it.

coachgeo:

On my '85, it runs nearly the length of the valve cover. Kind of a silver heavy gauge sheet metal thing. If you looked and didn't see it, I seriously doubt you missed it - it is more than slightly apparent in there. And as I said at the start of this thread, my '83 doesn't have this (Calif. veh. too) - dunno the answer there.

ahhhh what years have this valve cover I wonder. I want to keep a look out for one. Mine is a custom application so I dont know "exactly" what year my motor actually is. The # on the block is odd too from what I have been told.

Anyone know the best thing to use when the black silicone type stuff in the baffle fails, I don't want it falling into the engine.

I noticed that in mine yesterday, what exactly is the point of it?

Also, it would likely not hurt the engine, as if it fell, it'd travel back down into the sump, and would then either get caught in the intake strainer screen, or would end up on the oil filter.

The oil goes from Pan->strainer->oil pump->oil filter->rest of engine->back to pan (and some goes through the oil cooler if its open) So it'd probably be filtered out first.

my 85 doesn't have one

My 85 has the same thing. It`s attached from the middle of the valve cover, and about half way down the right side by rivits. It comes to about 1 inch to the rear for the opening inside. notice on the right side there is a ridge that slopes to the rear, that is what it is attached to on the inside.
so when the oil vapors are drawn in, some of the oil will be able to drain
back and not be sucked into the intake.
The CA 85 does not have the drain tube to drain oil back into the pan
from the air cleaner. the air cleaner sits behind the right front headlight
and makes a mess inside the bottom of it.
I was looking for a valve cover at the local junk yard since mine cracked
due to the broken timing chain. I grabed one off a real clean 80, then i
noticed it has a round pipe screwed inside and much shorter.
In my service manual for the 617.95 Turbo Diesel, it says

"For (usa) Federal 1980 the vent pipe screwed to
inside of cylinder head cover has been replaced by
a vent plate which is rivited-on and sealed with
silicone rubber. As a result, the volume of oil
separating space (damping chamber) has been enlarged.

This cylinder head cover is mounted as standard
equipment and for (J) from start of series".

And (J) at the top of the page states "starting 1981".

hope this helps.

Charlie