When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My 1949 Olds 88 with the 303 likes to mark its territory... I’ve got an oil leak out of the front of the engine, close by the harmonic balancer. I guess I’ll have to do something about it some time. Is this a typical leak site?
another question, on the rear right (passenger) side of the engine there’s what looks like a small exhaust tube. The kind you’d see on a small RV generator. I assume it’s some sort of crank case breather. Am I correct? It drips the blackest oil ever! It doesn’t gush out, but it steadily drips out after a drive. Thoughts?
Yes the tube is a breather. You could fashion a catch can there and empty it periodically just don't forget it's there.
Harmonic balancers are common leak points on most engines. As I don't have experience in that gen engine I would like to see what others have to suggest.
The tube at right rear is the engine's crankcase ventilation system. Commonly called road draft tube.
Before the days of positive crankcase Ventilation, engines still had to have a way to evacuate crankcase fumes and blowby. The oil fill cap was usually used as the fresh air intake for the engine. Look at the open end of the road draft tube and you'll see it's cut at an angle. When the car was moving, airflow under it created a scavenge at the road draft tube, pulling fresh air in thru the oil cap, thru the engine, and out the draft tube. When the car wasn't moving, no scavenge and the blowby smoke would often make you think the car was on fire if engine was really worn.
These draft tubes are why the middle of road lanes always looked oily in those days.
Keep the oil fill cap clean and system ought to function per design. Wash it in solvent, dry it and reoil it. Not much you can do to the tube itself short of pulling the intake and valley cover.
Last edited by rocketraider; Dec 30, 2020 at 11:14 AM.
Just thought I’d update people that may search this post in the future. I’ve moved discussion on how to access the front main seal to another thread called “harmonic balancer removal”.
