Once again I was looking up from the floor at my 235 engine trying to figure out where these oil drops keep coming from.I solved the big leak with a pcv valve (thank goodness)but I still keep getting a drop or two every time I drive it and let it set a day or two. I noticed a hole about 1 1/2" that I can see the flywheel teeth. There must be a plug or dust cover or something that I'm missing. I don't think any oil would be coming out there, but I really don't want mud and dust and gravel flying into the flywheel. Grin (not much chance of that..just saying). Any ideas?



It's behind the starter. I'm sure this display left it open just to see the parts. Does it have a cover?

Nope, at least not that I'm aware of. It's for timing your engine. There's a twin on the other side of your engine. You might look at it this way in that old Chevy sixes are like old Harleys in that if they aren't leaking oil they don't have oil in them.

The holes are for drawing in air for cooling the clutch. They must be open. Any oil coming out of the holes would be from a leaking rear main bearing or a cam plug leaking.

That's real easy to fix...Just drain all the oil out of your engine and refill it with those Styrofoam peanuts that they use for packing boxes...Sorry,I can't stand it any longer.HELP!

Do you work for BP ?

NO....I have NEVER BOUGHT ANYTHING FROM BP,I seen them coming many years ago... Did you say,one time,you worked in a Gov.Defense Plant?.....THE END IS NEAR.

It's near for me. I'll be leaving shortly..35 yrs co. service.

I've always assumed if it's not leaking, then it's out of oil. The car is 72 years old and it will leak a bit - get used to it.

Maybe you're too used to new Corvettes!!!

I can't understand that if it didn't leak oil when it was new ,why can't it be repaired to the same status? Everyone says "just live with it". Why? If it needs seals,gaskets,bushings,or whatever. Just find out which part is needed and replace it. Don't give up. Years ago old chevys leaked oil because parts and information was hard to come buy. People made do just to get by. There's no reason to do that now. Very few parts can't be found (well lets just say not to many). There's nothing I know of that GM made that was suppose to leak or seep oil. Restoring an old car means fixing it to the orginal status. I bet everyone that has a old chevy leaking oil has not got the same leak in the same area. I've fixed a bunch already. When I get them all fixed I'll post a photo of a clean garage floor with a 72 year old car sitting in it. Stay tuned. ( It may be a while)...grin

You guys who keep saying this is a 72 year old car are trying to prematurely age me!! I was "built" in 1938 also and I am only 71!!! Beamer

Steve, what we will want to see is a picture of the floor right after you have driven the car for about 20 miles. Any thing short of that and showing a clean floor will be suspect.

More, if you can stop a 216 from leaking then you are going to be our hero (loose interpretation, of course). Anyhow, just so you know, we understand that you have a 235, which owing to a lesser exposure for the side pan, will give you a pretty hefty edge. Nonetheless, it still can't be done. The 216 was not designed to be leak proof and the 236 shared enough of the same leak points, that it's very similar.
Best and good luck,
Charlie

BTW: Use of that PCV valve and any other nonstandard device, apparatus or Tennessee engineered widget in your quest to build a non-leaking 216 will be considered a-cheatin'. (grin)

OK..I yeild to a superior power. I'm new to working with 216/235 engines. You say it can't be done. OK..for the sake of argument. Which part CAN NOT be stopped from leaking? Is it a oil pan gasket,a valve cover gasket,side cover gasket? All I see is two metal machined surfaces. Why won't a gasket hold the leak? I'll admit the oil tube/vent/whatever more than likely was meant to drip oil. Other than that, a gasket should work.

I do not believe that it is impossible to fix most leaks on a 235 or 216. The one exception is the rear main seal which a lot of people have trouble with. On my 1951 216, the secret to success was installing new main bearings and adjusting them properly. My rear main does not leak now but I have been chasing another leak at the front, the source of which eludes my detection at the moment.

Steve, it is simple. Even in a new or rebuilt engine, over time (a little over a nanosecond) the erl will permeate the cork seals of the erl pan, the side pan, the valve cover and the seals at the front and rear. Also, it will soon saturate the vent pipe.

You see the erl is like a caged animal, it is constantly trying to escape. Sorta like if you were made to live in say WI or OR. You wouldn't be none too happy and would be constantly prowling around, looking for escape routes south. Well, just picture the powers to be as having made many of the routes with rickety gates (cork) and all you have to do is keep a-slipping by till you get enough of you by to form a big a drip. You'd be home free and looking for the Orange Blossom Special to take you on down to Florida or to the floor in the case of erl. Yep. That's the way it is. Especially for a 216.

Best, Charlie

BTW: The reason they didn't put elf filters on the 216 was because all you'd get was a trickle anyway. No, the engineers figured that the erl would be changed owing to seepage. All that was necessary was to add a quart now and then. (grin)

When these engines were new they really didn't leak. If they had a leak the customer would come back and have it repaired under warranty.

Common areas to leak were :
#1 - the valve cover gasket. The oil could wick through the cork on some gaskets. Today the covers are often distorted from over tightening. Modern gaskets very hard material.

#2 - Side cover gasket. Today the side covers are often distorted also. The modern gaskets, while of good quality, are much harder than the original cork and cannot seal to a warped side cover ( or oil pan.)

#3 - timing cover seal (cover not centered perfectly on the balancer) - tool made for the purpose.

#4 - leak between front main bearing cap and back of front mounting plate. Rear mounting plate covers this but mechanices would use Permatex on the front of the cap to make a positive seal.

#5 - Oil pan gasket installed incorrectly. Long side gaskets must be installed before the end corks. Pan distorted? Use small dob of sealer where side gasket and end gasket meet.

#6 - Fuel pump, the pin for the fuel pump arm can leak at the body casting as well as the pump to block gasket.

#7 - Rear main bearing....several cures but can be a problem.

Do not over tighten the cork gaskets but do go back every week or so and retighten - for three or four times.

#6...I noticed my pin moves toward the front of the car ,hitting the bolthead that holds the pump to the block. It doesn't appear to leak ,but it could be. Short of replacing the pump,is there anything that will help leakage in that area? I was thinking a small dab of gasket sealer over the pin itself. The pin is only about 1/16" in diameter. Whata think? I may lose the war as far as stopping leaks,but it's going to be a heck of a battle. GRIN

Not sure what your fuel pump looks like. There are several designs of the AC brand, Some have the pin stakes in place, Some have a washer on either side with retainers and some have a shorter pin and tiny plugs in the holes. I used JB Weld on one of mine and it lasted only a short time.
My choice would buy a new quality pump.

Mine ia a straight pin. It floats from side to side. I pushed it back to the center and put gasket sealer on the sides. The pin is only about 1/8".It may help, I doubt it but it's a shot. If that doesn't work I'm going to use 3 washers instead of one. That will force the pin to be in the center.

A method of holding the pin in place would be to lightly centre pop the housing close to and around the pin. Then if there is a oil leak apply some sealant.
Tony

On a vehicle that is driven regularly, there are two areas on the 216 engine that cannot be made drip-tight without modification. One is the crankcase vent pipe, and the other is the rear main seal.

On a new or rebuilt engine, until the piston rings are fully seated, or on an engine with 30,000 + miles, exhaust gas blow-by creates excessive crankcase pressure. The gas pressure is vented to the atmosphere through the crankcase vent pipe, and the greater the pressure, the more oil vapor is entrained and carried out with the gas. The oil vapor condenses on the vent tube and on the right side undercarriage of the car and forms droplets which eventually drop off onto the clean garage floor. If you've added a PCV setup to your 216, you may have solved that problem, or at least reduced it by a great deal.

The problem with the rear main bearing seal is its design. The flat rope-type two piece seal simply cannot maintain a drip-tight seal for an extended period. The wide contact area of the seal on the crankshaft results in heat buildup which leads to rapid wear of the seal itself as well as on the crankshaft surface, ultimately resulting in leakage. A new seal on a new or freshly ground crankshaft surface may run as many as a thousand miles or more before beginning to leak, but eventually, the seal will leak as the miles accumulate on the engine. Modern-day elastomers and lip type seal design can tolerate the higher surface speeds and temperatures encountered at the large diameter crankshaft flywheel hub (where the seal runs) and would probably run many tens of thousands of miles before leaking--assuming the main bearings are kept in adjustment. There is a company, Beck Machine and Tool in Santa Maria, California that can modify the 37-39 Chev 216 rear main seal cavity to take a modern one-piece lip type seal. Besides being leak free, this arrangement allows the for seal replacement without removing the crankshaft, though you would have to remove the transmission, clutch, and flywheel. I'm hoping to try this mod on my 40 Chev, but I'm not sure how to deal with the effect that removing rear main bearing shims will have on the seal cavity bore diameter. That is, if you bored the seal cavity with the recommended four .002" shims installed on each side of the rear main bearing cap, each time you removed shims to adjust the rear main bearing, the seal cavity bore diameter would be reduced. Perhaps the seal can tolerate a certain amount of ovality caused by removal of shims.

Mark Yeamans
VCCA #35724

Sounds right to me. I added the PVC valve and got rid of 80% of my problem. I'm not correct and the old vent pipe looks cool,but no more oil on the floor or driveway every time I drive it. My 235 has unknown mileage,but I'm sure it has plenty of useage. I'm going to experiment with the fuel pump pin and try to get rid of another 10% of the problem. Thanks for the input.