Rebuilt 69 396/325hp with 75 miles on it. Had no leaks after first trip of about 20 miles. At 30 miles (second time out) I noticed oil dripping off the starter. Back of the block is dry. It's dry around the distributor and the intake. No leaks around valve covers. Dry where the heads meet the block. If I wipe everything dry and go out for a drive I find oil dripping off the bottom of the starter. I can see where it ran down the solenoid and see drops on the wire loom above the solenoid. Also a drop on the block just above the wire loom. But the block is dry all around this whole area and as I said the intake, distributor and back of block are dry. Can also see oil on the flat flange around the oil filter but it's dry up where the filter seals against the block. Can see oil on the bottom of the oil pan which seems to come from between the pan and the triangle shaped stamped piece that's welded to the pan to hold the tube fitting, but it's dry where the dipstick tube fits into the tube fitting. Also dry on the back of the pan. This is a new chrome pan from jegs. Could there be a leak where the tube fitting is welded to the pan? If so how does the oil get up to the solenoid and wire loom which are above the tube fitting? I have retorqued the pan bolts (135 inch pounds and 65 inch pounds by the timing cover) a couple of times as they seem to be loose evertime I check them. I've spent the whole weekend trying to find this leak and I've about had it. Oh yeah, the engine was professionally built, didn't build it myself. Who has an idea? HELP!

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This is so much fun I can't believe it's legal.
www.chevelles.com/showroom/birjrm2.jpg (http://www.chevelles.com/showroom/birjrm2.jpg)
www.chevelles.com/showroom/birjrm1.jpg (http://www.chevelles.com/showroom/birjrm1.jpg)

Two things come to mind to me. The first are you running a pcv valve? I have had oil come back up the dipstick tube when I did not have one. I am not real familiar with the big blocks as the one I have now is my first. ( NOT going back either!) But on a small block there are two holes on the front of the engine right in front of the fuel pump.They used to be where the small block mounts went in pre 58 cars. (God I am getting old!) One of these holes goes into the pushrod for the fuel pump, and if you do not have a short bolt in there, oil will leak out real bad. Again,I do not know if the big block has this or not. You are certainly in the right place though! Someone here will fix you up!

Bcice... both valve covers are vented. Drivers side to the carb, passenger side to the air cleaner. There is a plug in the hole where fuel pump push rod goes.

You mention that both valve covers are vented, but do not say that you are running a PCV valve. If not, you would find that a good starting point. Otherwise, I say that your pan is leaking at the rail/bolts. Who knows, maybe your pan bolt retorque has slightly bent the pan rails. My 406 had the oil pan installed at a shop - they used bolts that were too short, and they always loosened up because they were never really seated. Oil can travel away from the leak source - this is where that black light oil dye comes into play. Most all shops/dealers have the oil dye, go get some. Then put your car up on a lift and see where the black light shows the dye - that is where your leak is.

Best of luck, Thomas

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"Bomber" '67 El Camino, Beater comes back to life.
Was 350/TH350 14.90 @ 93mph, 360,000+ miles on car
Now 406 roller, 340rwhp, more hp coming, 3.08 gears
Street radials, left in drive, 13.20 e.t.@108.35 mph
8/1/01 added Plum Mist '67 to collection
*New* 468 on its way - going Big Block!

JRM. Not long ago, I remember seeing this topic was dicussed at length. Whoevers car had an oil leak argued that if it was vented, he did not need a pcv valve. I would have to go search for it to be sure but if my old memory serves me correct, he finally went and tried a pcv valve, hooked it up to the correct spot and SURPRISE!! no more oil all over his motor! Pretty cheap thing to try anyway.

jrm,
I'm not familiar with the big blocks but I chased an oil leak on my SB for a couple of months. The oil showed in the same areas you described. I snugged up the bolts on the timing chain cover and it no longer leaks. If all else mentioned above fails, this is worth looking into.

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Honey, its not a $200 hat. The distributor was $200, the hat came with it. kevin d
Maryland Chevelle Club #362
Classic Cars and Trucks of Beaufort #72
TC #1108
ACES #4586

I'd like to change my name before admitting to this one, but here goes;

I chased an oil leak at the rear of my small block and even went so far as to replacing the oil pan gasket and rear seal. I was at the point of thinking that the crank surface (where the rear seal comes in contact) may be scored and have to be turned!

The problem was that the oil filter wasn't tight enough and when pressure built up, it would blow out oil. The oil would work it's way back to the torque converter, and that would hide all traces of where it originally came from.

I now tighten the oil filter well beyond all recommendations (and have no problems).

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Wes. Vann
Technical Reference section
Gold Member #5

JRM,

I had a similar problem on a big block. Come to find out, the intake manifold was leaking. I used the gasket instead of silicone. The leak was undetectable from the back side of the block. As in your case, oil was dripping off the starter. The oil runs between the block deck and the head. There is space at the rear of the head gasket where the oil travels. It was very aggravating but a simple fix. Pull the intake, use silicone to seal the front and rear of the intake, and this should fix your problem.

Bomber67...yes I'm running a PCV Valve on the driver side. Passenger side calls for open vent.
WesV....My filter is tight. As I mentioned I can see the seating surface is dry and the filter is as tight as I can get it by hand.
JaxSS....Yeah I guess it could be the intake leaking as you describe. I ran a paper towel down the back side of the head at the gasket and it did come up wet with oil even though it feels dry to the finger. I'll check that out. Thanks.

See if you can find a shop that can put a fluorescent dye in your oil (harmless) then check with a black light to see where the leak is.

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Nick P.
Team Chevelle Gold #36
http://people.ne.mediaone.net/nicpal/home.htm www.chevelles.com/showroom/Nick's1970ChevelleSS396.jpg (http://www.chevelles.com/showroom/Nick's1970ChevelleSS396.jpg)

A couple of things: First be sure to check the camshaft plug and the oil gallery plugs (2) in the back of the engine. They too can leak and windage from the flywheel will deposit the oil in the place you are finding it.(This is much less likely than the intake manifold but I have seen them leak too many times.) Secondly you mention having to re-tighten oil pan and timing cover bolts that seem to come loose. I would suggest using "loctite" on those bolts. They won't come loose again.

Just got the chevelle back from my mechanic (not the engine builder), took it to him yesterday out of frustration. They couldn't find it either. This is a local shop with 4 mechanics, 3 of whom build hot rods and race and are chevy nuts. charbilly....I'll check the plugs and 10-4 on the locktite. Narti...I guess it's time to dump the psychodelic dye in the motor and see where it finds a hole. O.K. I live in a very rural area (have to drive a half hour just to buy underwear) what is this fluorescent dye called so I know what to ask for after driving an hour to get to parts store that might have some. Thanks Guys!

[This message has been edited by jrm (edited 10-25-2001).]

I live in a very rural area (have to drive a half hour just to buy
underwear) I damn near peed when I read that. You gotta give a guy a warning b4 you pop a funny like that!

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1970 SS454 LS6 Chevelle, Damn! why did I sell that car?