Hi guys. I'm trying to trace an oil leak coming out of the passengers side front of my 1967 stock 283 motor. At first I thought it might be from around the (mechanical) fuel pump (which is obviously a new replacement from its sparkling condition), but I cleaned around it and sealed it up well with form-a-gasket and it didnt even make a dent. The car leaves 7 or 8 large drops of oil on the floor every time I come back into the garage, and the steering arms forward of the engine are covered in it as well. The oil is fairly new and clean, so finding the leak is tough.

The engine has obviously been rebuilt (or at least overhauled and detailed) in recent times, thought I have no service records on it. Neither of what appear to be the stock valve covers have a breather cap or PCV valve in them, could it be that the oil pressure in the block is getting too high, and I have a leak out of one of the main seals as a result? Do I need to get valve covers with breather caps, and shouldnt this car have a PCV valve?

First off we need more details on the car/motor, and totally stock, modified etc...
Older motors did not have any holes in the valve covers, but did have an intake breather. We need pictures or details.

-Bobby-

It looks to be the totally stock 283 motor on a 67 Malibu. Carburator is a stock (Rochester?) two barrel. I'll try and get a pic.

Whats the intake breather....some kind of vent on the intake manifold?

It looks to be the totally stock 283 motor on a 67 Malibu. Carburator is a stock (Rochester?) two barrel. I'll try and get a pic.

Whats the intake breather....some kind of vent on the intake manifold?

There should be a tube sticking out the front of the intake manifold. This is where you add oil to the engine. The cap on this tube should be a breather cap.

If your leaks are at the front, chances are it is leaking at the front main seal and/or the joint where the front timing cover meets the block and the oil pan. This is all behind the harmonic balancer and so the source of the leak can be hard to spot.

there is 2 bolt holes on the lower front of the block adjacent to the fuel pump. The bolt hole should have a short 3/8 bolt in it with a little sealer of some sort, if not it will cause an oil leak. if its missing make sure you use a short (1/2 or so) 3/8 to plug it as a longer one will hit the fule pump push rod

If you are having trouble finding the leak you can get a small bottle of florescent dye from napa. Before adding the dye clean up the oil as best as you can. Add the dye and run your engine for 10 minutes or so. Then put a black light on any suspect areas. The leaking area will glow. You can also put compressed air down your dipstick tube ( make sure to use only 15-20 PSI ). With the air pressure applied crawl underneath and spray any suspect ares with a soapy water solution. Any leaks will produce bubbles in the solution.

ktrim, I think you are on to something! I remember an exposed bolt hole there....I'll check when I get home.

Should the bolt seal it like a drain plug on the oil pan. In other words all I need is a short 3/8" bolt with a washer and rubber or cork washer underneath?

ktrim, I think you are on to something! I remember an exposed bolt hole there....I'll check when I get home.

Should the bolt seal it like a drain plug on the oil pan. In other words all I need is a short 3/8" bolt with a washer and rubber or cork washer underneath?

Just a short bolt and maybe a lock washer, and little thread sealant will do the trick. there are 2 bolt holes there, the bottom one can be left open, the top one needs the bolt

ktrim, I think you are on to something! I remember an exposed bolt hole there....I'll check when I get home.

Should the bolt seal it like a drain plug on the oil pan. In other words all I need is a short 3/8" bolt with a washer and rubber or cork washer underneath?

You'd be better off cleaning the hole with some brake cleaner and installing a bolt with some silicone RTV on the threads.

Just a short bolt and maybe a lock washer, and little thread sealant will do the trick. there are 2 bolt holes there, the bottom one can be left open, the top one needs the bolt


That is exactly what I was thinking earlier, but there was not much info.


If it does not have that bolt in the front of the passenger side, use rtv and add a bolt. Then you need to look into the breather,vent,pcv valve.
The motor needs to breathe and a pcv vavle is a great way to make it work for a stock motor. Now if you have the solid vavle covers you may need to look at other options.

Still take a few pictures, a few around the intake and valve cover area without the air cleaner in place.

-Bobby-

check for a "road tube" coming off the block near the distributor. this in conjunction with the breather up front and movement down the road evacuate the fumes from the block. this tube may have been removed and the hole plugged causing problems. if the hole is plugged then a PCV valve needs to be installed.

Hey guys...is this the PCV valve? its behind the distributor and has a line running to the carb so I assume so but wanted to check.

Thanks for all your help!!

http://i215.photobucket.com/albums/cc276/KOQueer/PCV_valve.jpg

http://s215.photobucket.com/albums/cc276/KOQueer/?action=view&current=PCV_valve.jpg

That is the breather out of the crankcase, yes. That's probably a "fixed orafice" PCV (it won't rattle like most which is a test to see if they are still good). So the crankcase gasses are pulled out of the engine there and run back into the intake manifold. To make it all work fresh air has to get in. Check the cap on the oil fill spout at the front, it should have air inlets at the bottom with what looks like really coarse steel wool inside. If it looks pretty gunked up, spray it liberally with carb or brake cleaner to get all the gunk and old oil and grease out of it.

It also looks like your valve cover gaskets are leaking pretty good too.

That is the breather out of the crankcase, yes. That's probably a "fixed orafice" PCV (it won't rattle like most which is a test to see if they are still good). So the crankcase gasses are pulled out of the engine there and run back into the intake manifold. To make it all work fresh air has to get in. Check the cap on the oil fill spout at the front, it should have air inlets at the bottom with what looks like really coarse steel wool inside. If it looks pretty gunked up, spray it liberally with carb or brake cleaner to get all the gunk and old oil and grease out of it.

It also looks like your valve cover gaskets are leaking pretty good too.

Thats just the lousy paint jobflaking off on the block, but the sides are not oily so I dont this the valve covers are greasy.

I meant to say " I dont think the valve covers are leaking"

by the way that whole "shake it, if it rattles its still good" theory is BS. i just had a major problem with burning oil and smoking at WOT and it was due to a faulty pcv valve, and when i shook it, it still rattled. i held up a new one and the old one and the new one rattled MORE than the old one, but the old one still rattled. for the $2.50 just replace it and be done with it.

crawl under the car with a 1/4" ratchet and make sure the oil pan bolts are all tight.
also double check the valve cover gaskets- they can leak just enough to make a mess, but not enough to see on the engine.
look at the corners of the intake manifold- where the heads, block, and intake manifold meet up at the front and rear of the block is a common leak point.
could also be the front seal behind the harmonic balancer.

Hey guys...is this the PCV valve? its behind the distributor and has a line running to the carb so I assume so but wanted to check.

Thanks for all your help!!

http://i215.photobucket.com/albums/cc276/KOQueer/PCV_valve.jpg

http://s215.photobucket.com/albums/cc276/KOQueer/?action=view&current=PCV_valve.jpg

The arrow is not pointing to the PCV valve. If you follow the hose the PCV valve should be screwed into a fitting usually on the rear of the carb. I am 100% sure that the bolt mentioned earlier is missing from the front of the block. It won't leak oil through the bolt hole at idle, but if you hold the RPM about 1500 it will pour out a lot of oil.

Paul