Rvsmith5

I hope I don't **** anyone off here, but I am wondering if I can run my 455 with a slight leak in the front and rear main seals? As I was working on my floor pans today I noticed oil runs from both seals. They are small, not even dripping on the floor yet. Engine had sat for 20 years plus, so I suppose it is not a surprise. I just really want to enjoy it a summer before I go all in on a full resto.

Thanks,
Bob

joe_padavano

You won't find any engine that doesn't have SOME seepage past the seals.

oldcutlass

Just check and add oil as required regularly to keep it full.

Tedd Thompson

Most all Oldsmobiles will need to be paper trained especially ones that have sat for years. I blame the issue on the rope seals that oldsmobile used till the the end of the rocket era. It may get better as time and mileage increase but don't bet on it. It doesn't sound like you really have that bad of a problem anyway..... Tedd

matt69olds

Why would a small leak **** anyone off here? Maybe if you park in someone’s freshly paved driveway, I could see annoying someone.

As Joe mentioned, chances are every Olds engine seeps a little oil somewhere. Unless its waving huge puddles, don’t worry about it.

chuck_royle

If your Olds ain't leaking oil, you'd better put some in it..

BillK

It doesn't "**** me off" but it aggravates the crap out of me I hate oil drips on the garage floor and especially on my concrete driveway. The 307 in my Wife's Riviera leaked from the rear main seal from when the car was about two years old. It got bad enough that I had a drip pan under it for the last 10 years or so. When I rebuilt the engine 2 years ago I used a two piece rubber seal and so far it has not leaked a drop. Has about 15K miles since I did it.

Rvsmith5

I always worry on this site that someone will be upset because I am not doing things the "right" way. Over the years I have worked on quite a few cars and every once in a while I touch a nerve and get someone all fired up about my lack of knowledge or ability. Just gunshy I guess. I though maybe people might think it is stupid to risk wrecking it. I am glad I can still try to get it to the point I can enjoy it this summer. Seems the perfect tool for social isolation.

Thanks everyone.

Bob

JohnnyBs68S

+1. In fact, any engine that has a stamped steel oil pan and valve covers is going to leak.

Sugar Bear

Bob,

Neither the front or rear crank seals are pressurized so theuy won't suddenly rupture and dump all the oil damaging the engine unless it is run out of oil over time.
The leaks may even lessen with use.

Drive and monitor the leak and the oil level frequently. If it gets bad then stop driving it. Also watch for any excessive oil on an exhaust pipe that could be a fire hazard.
​​​​​
If you have questions don't be concerned about hitting a nerve. Your question is a valid one in your circumstance.

Good luck!!!

stan 65 cutlass

if you can wipe it off after every trip or so it keeps it from making a large mess

android 211

There's 'snake oil' products that may alleviate leaks somewhat for awhile. The front leak can be more easily fixed by removing the timing chain cover and replacing the seal. The rear main seal leak will require removal of the engine. Some shade tree experts can remove the oil pan then the rear main and snake out the upper seal with a piece of wire with the engine still in the car but I think thats a lost art. Especially dragging the new one back into place.

droldsmorland

Verify the PCV valve and its hose are good. And the valve cover breather(s) is unobstructed.
A pressurized crankcase will leak like hell from anywhere it can get out.

damaged442

All my cars tend to mark their territory. It's just part of life with older cars! i certainly wouldn't lose much sleep over it.

chuck_royle

Exactly, which is why parts are aluminum with machined surfaces. Fewer gaskets are used now, mostly sealants in between timing covers/oil pans. Any gaskets are rubber with crush prooofing or fit into a grove on one of the al. parts.

chuck_royle

Exactly, so many overlook this. Everytime I get an equinox/terrain with a 2.4, if the pcv is plugged, the rear main seal will push out. I often estimate a 2hr repair to re and re the intake and repair the pcv, they don't believe me and drive away. Soon after it's back on the hook with oil flowing out the rear. A 2 hr repair becomes a 2hr plus a 10hr repair.

oldcutlass

In my experience what normally happens to Olds V8's with a bad pcv and ton of blowby is you get a bunch of oil pushed out the oil fill and dipstick tube. Never seen a seal blow out.