Engine leaking oil!!

BFS57 · July 03, 2010, 08:52:04 PM

Hello;
I have a 350 in my 57 chevy daily driver. It leaks oil all over the place! Could be the pan, could be the front and rear main seals! Took it to a shop to discuss this problem and was told that in order to fix the seals the motor would have to be pulled out.
I was under the impression that these seals could be done without removing the engine.
Anyone got some words of wisdom on the subject?

Bruce

Carnut · July 03, 2010, 09:03:33 PM

Gee, I've never had to remove an SBC from any of my Tri-5 chevys to replace any seal. Now the rear main seal would mean removing the transmission and the fellow might think pulling engine is easier, but it never was for me.

Only SBC I've ever 'Had' to remove was in my 65 El Camino to replace the oil pump. All the manuals said remove engine to replace seal, and I tried several times to prove the manual wrong only to find that there really was no other practical way to pull the pan other than removing the engine. One of the main reasons I no longer have a 65 El Camino.

unklian · July 03, 2010, 09:17:40 PM

Some cars you can't get the oil pan off without pulling the motor.

57larry · July 03, 2010, 09:25:46 PM

pulling an engine out of a 57 ain't too bad to pull. ask a buddy to help you

wayne petty · July 03, 2010, 10:01:51 PM

pressure wash the engine compartment first...

some places may have a drive up ramp.. so you can do the underside..

these are usually found at normal drive through the machine car washes.. not at the quarter car wash... so you might have to pay to get the underside done well...

there is nothing worse that having to fix an oil leak.. that has spread oil all over the bottom of the car..

a question on a 57... do you still have a road draft tube???

do you have a PCV in the filler tube stuck into the front of the intake???

do you have a breather someplace.. perhaps the top of the oil filler tube.. so the crank case pressures cannot be built up or vacuum created..

excessive crank case pressure is one of the causes of oil leaks...

along with improperly installed valve cover gaskets.. and leaking oil sending units or oil pressure lines..

blown out intake manifold end seals runs a really close second..

a rare thing that does happen.. the outer ring of the damper can slip and wear a groove in the timing cover.. this can really make a huge mess...

one can also spray the engine with several cans of brake cleaner to clean the mess but it has a tendency to harden the seals... but it sure drys the oils up fast...

tomslik · July 03, 2010, 10:52:17 PM

#1, it takes about 10 min. to pull the pan on a 55-57 chevy WITHOUT pulling the eng.
#2, i'd look REAL close at the seal on the backside of the intake...
also could be the dist gasket or the oil pressure sender

unklian · July 03, 2010, 11:56:50 PM

I've had some pesky oil leaks, very hard to trace.
Eventually I learned of this method:

Get the motor hot, wash the motor,
let dry, then spray in gray primer.
Start the motor.

If the leaks don't show, drive around the block once, and check again.
Dirty oil shows up clearly on gray primer.

If the motor is all black, good luck finding the leak.

I've had three cars with holes rusted in the sides of the oil pans.
Changing seals and gaskets wouldn't have solved those problems.

BFS57 · July 04, 2010, 08:11:31 AM

Hello;
Thanks for the words of wisdom.
I have a breather on one of my valve covers,but I Don't think it is enough as I have fought leaking oil through the bolts holding the intake down. So excessive pressure might be part of my problem.
I don't think that the rear main seal is leaking as I have heard that on startup you have oil coming out.
The oil sending unit on this motor was replaced with plumbing to a oil gage and I have looked and don't seem to find any leakage here.
When I had the intake replaced, originally, It leaked along the side gaskets so I took it back to the guy that did it and he replaced the gaskets as well as a thick bead of ? along the front and rear so I don't think it is that.
As far as the seal from the dizzy, I don't notice any but I'll check that.
I do know that the bolt in the pan to change oil leaks no matter what I have tried, maybe I have a bad pan. I do have one of those one piece pan gaskets ready to go on. I notice oil coming from the front of the pan up by the crank area. I recently got under and checked the tightness of the bolts on the pan and found that most were quite loose. snugged them up but didn't overtighten (I hope) any.
Making it more difficult is the fact that I live in an area with one of those HOA sooo.. I really can't do too much at the house so I drive it to work, pull it in the warehouse and do what I have to inside at the end of the work day.
Thanks to all that responded and, Keep the suggestions coming.

Bruce

chopped · July 04, 2010, 08:31:51 AM

Some engines have a hole for a dipstick on both sides. We found a leak caused by one not having a plug in it a couple weeks ago. Was in a vette with a crate engine.

Charlie Chops 1940 · July 04, 2010, 10:40:06 AM

Chevy did a good design on the PVC system starting about 1962. Usually a PVC in the pass. side valve cover to the big port on the back of most carbs and then a tube from the drivers cover into the air cleaner base. If you run an engine without a complete PVC system or a draft tube(which still oils up the bottom of the car if you have any blowby) it will tend to weep out of the valve cover gaskets, front cover, intake front and rear and the pan gaskets. The best engines build up pressure in the crankcase - easiest way to control it is with a complete PVC system.

Charlie

348tripower · July 04, 2010, 01:34:28 PM

And, if this is a mechanical fuel pump engine, make sure that there is a bolt on the front of the block plugging the hole that you would put a bolt in to keep the fuel pump rod from dropping during a pump change. Ask me how I know!

enjenjo · July 04, 2010, 03:12:17 PM

At the front of the pan, there are two gasket thicknesses possible. One is nearly 1/2" thick, the other only about 1/4". If you need the thick one, but have the thin one in there, it makes a bad oil leak.

BFS57 · July 04, 2010, 06:07:57 PM

HELLO;
Charlie Chops may have hit the nail on the head. I don't have a complete PVC system. Only a one way PVC valve going into the base of the carb and a cap on the opposite side that has vent holes on the bottom. I should change that to a cap that has a hose connection and run that into the base of my air cleaner. Good point.
As for the missing (or a) bolt on the front by the fuel pump, I'll take a closer look.
My dear friend Larry Barickman built this motor and he was one of those guys that really had a lot of Chevy knowledge, sadly, he passed about two years or so ago but anyone that has looked at the motor has commented how good it looked (inside).
It's poring Rain here in Orlando so any car stuff is on hold. Thanks for so many suggestions and I'll check each and every one of them.

Bruce

39deluxe · July 05, 2010, 12:46:12 AM

It really doesn't make any difference if the vent is a vented cap on the valve cover or if it's connected to the air cleaner like a stocker. Just as long as it's vented and the PCV valve is working to draw a vacuum on or allow pressure to escape from the crankcase it's a complete system. The PVC is clean and the check valve rattles when you shake it, right? Excessive blow by can overpower the PCV system and cause oil to seep out around the valve cover gaskets and other seals. This should not be a problem with your engine if it's only 2 years old and was assembles properly. Of course 2 years is a lifetime for cork valve cover gaskets in most cases.

A road draft tube blowing oil out was common on these cars with higher mileage. That doesn't apply to your car since it has a 350 block. No 350 block was ever bored for a crankcase vent connector or road draft tube like 327 and smaller engines were.

I'd follow the above advice and thoroughly clean the engine top and bottom. Drive it a day or 2 and then go looking for fresh oil leaks.

Tom