The Stovebolt Site Forums The Shop Area Engine Shop oil leaking from head on refill?

So I dumped my 20 year old oil yesterday and refilled. I think the previous owner was a little overdue...

When replacing the oil, I poured it in as quickly as I could thinking that the oil would have a better shot at getting to the rockers of the last cylinder toward the firewall before draining back to the pan...

After filling I noticed oil leaking down the passenger side of the block back by the 5th from front cylinder. ( above starter)

It seems to be coming from a hole in the head just below the valve cover gasket surface. Is there a weep hole or something back there so that oil cant pool up over the rocker arms?

I also noticed 1" x 1/16" slots cut in the top of valve cover. I think there are 2 on each side at either end and they are right in a bend that forms the emboss shape on top of the valve cover. normal?

Nevermind the valve cover question... found the vent info.. I'll prob seal them and ad a cap with a breather...

Tj

I'm aware of no such vent. Can you post a photo?

i was goign to link to a similar pic but i can't get into my flickr right now... it seems to be just behind the rearward coil ( coil right?) mouting hole toward the top surface of the head. the casting is elongated here but i assume it is just for the valve cover blind hole comign from above...

maybe my coil is only mounted ion one hole, but i coud swear there was a 1/8-3/16" hole int htis area with oil coming out...

i'll have to get a pic next time im back at the truck..

Tj

Is it possible that it was leaking out of the side cover? Could have backed up in the lifter area when you dumped the clean oil in. The side covers are known to leak.

It could be, but it sure seemed convenient that there was a hole there... and of course I can't find a pic of a head with a similar hole on the net right now....

Tj

I take it it is a 54. If it was an earlier engine it could come out of the seals around the spark plugs. There are 2 holes for the coil mount. If there are not bolts in both of them oil can run out.

don't seal up the vents, you need them, even with a breather cap water condenses in the back part of the valve cover and rusts it up to the point it will flake off large chunks of rust into your engine. I know because I did it...

If I understand you correctly, there are two threaded holes just underneath the valve cover. These holes are for the coil strap. If you are not running the stock coil or strap, put a bolt in the hole with a little teflon to stop the leak.

I didn't think it was one of these holes but it may have been. ill have to check this weekend... if it was a threaded hole id say it was a #10 or so... definitely not 1/4" ....

Tj

What size and year engine is it?
On this page the 2nd and 4th engine pictured on the left (gray) and (red valve cover) you can barely see a small pipe plug in a 1/8" NPT hole...
I don't know why it's there, but it connects directly to the rocker area.

That's the plug for the oil passage to the rockers.

pretty sure its a 235 from a 54 1/4 ton.

You posted a T54X engine code suffix.
1954 3100 (1/2 ton) truck engine assembled in Tonawanda, NY

By the way, I have had many 1954 engines with original, slotted, valve covers and I have never had rusting on the under-side of the valve cover. I also made sure that all my engines had oil feed to the rocker arm assembly, resulting in oil sloshing inside the valve cover.

People have reported water leaking onto the engine through the hood (I have never seen that). If I observed that, I might consider sealing the slots/slits in the valve cover or using a newer valve cover (and then using a breather oil filler cap).

no you missed the entire point, the rusting resulted from sealing of the vents, not allowing the moisture to escape. The end with the breather cap was fine, the other end was the end with the rust. Just the last 3 or 4 inches. If you have no way for the moisture to get out it doesn't matter if there is oil or not, it will still rust. Which is why the military, (at least the navy) went to vapor space inhibitor oils in the large sumps which mostly prevented rusting of the tops of oil tanks. not completely, but it did make a considerable difference. And they did rust, large sheets of it. If I were to use a steel valve cover again, I would seal up the vents and construct some sort of PCV system.

No, I did not miss your point. But, I should have continued by stating that I have also never found rust inside a non-slotted valve cover with a breather filler cap, as long as I made sure that oil was reaching the rocker arm assembly. Sorry for my lack of clarity/completeness.

I have only had one of these, but I have had it a long time, and all I know is every time I took the valve cover off for the last 28 years, there was rust inside. True it is a 1953 216 maybe there is some incredible difference between the two that isn't readily discernible. Even the new engine with a non slotted aluminum valve cover has a lot of condesation when I take it off, and it gets lots of oil up there. With the old engine it took about an hour of freeway driving to evaporate all the milky colored oil out from around the breather cap.(well in the winter time at least) I have always attributed it to my sealing up the vents, which I did in 1985 in a attempt to reduce dust infiltration. But now I am confused.

I have no doubt that rust on the underside of the valve covers happens. I saw it all the time in the late-60s/early-70s when I often worked on old 216/235 engines. Yes, good ventilation and warm-up is key to minimal or no rust. However, I often had to clean out gummed-up "ventilated" filler caps; and, I often had to give up on older engines that had gummed-up/clogged oil lines leading to the rocker arm assembly.