Low oil pressure-oil dripping off bell housing

[6D5]

Driving at 35mph, smelled burnt oil, saw oil pressure gauge showing 20 PSI (usually 45-50psi at 35/40mph). The engine had oil dripping from bottom area of bell housing when I shut it off and pulled over to the side of the road (big puddle). Called Jardan hauler, had it taken home (10 miles away).The engine is a 440RB, headers etc. with a 727 transmission. I drained the 7 qt oil pan and had 5 qts left in the pan when I drained it(measured). Oil was not burned/dirty/contaminated etc. Cannot see any oil on flex plate, flex plate bolts when I removed the lower tranny bell housing torque converter inspection cover. Haven't pulled tranny or engine yet. Car is a '65 Belvedere II convertible. Any ideas?

 

[HT413]

How long did it take to lose the 2 quarts of oil? Is this motor new or is this a new problem on a known good engine?

My initial thinking is this - any external oil leak that causes 20-30 psi of oil pressure loss AND a loss of 2 quarts of oil would have to be (?) pressurized oil and would likely be extremely noticeable - as if the oil pressure sender were lose and pretty well gushing oil. The sender, coincidentally, is toward the rear of the motor.

I just don't think there are many places that the oil galleries could leak pressure AND oil outside the motor, so is it possible that you have 2 problems? Maybe a badly leaking valve cover gasket AND...

Speaking of that oil sender, is it possible that it is malfunctioing? Sounds like you have an oil pressure gauge and not just the dummy light. Is this a mechanical gauge and if so, could there be air or some debris/clog in the line? Is the capillary tube kinked and pissing oil on a header? (Not sure this is is even possible to would take an eternity for a capillary tube to piss 2 quarts of oil I think).

I have a gauge and the dummy light in my 413 - the OEM electrical sender plus a capillary to a mechanical gauge. Do you have the same? If so, try cranking the motor over (with the coil wire off). At what pressure does the dummy light to off? I think OEM senders are set to turn off the light at 8psi(?)

The fact that you still have any pressure at all tells me the oil pickup isn't sucking air, so the lack of oil is a symptom not a cause.

Sorry for the stream of thought lol, I'm having a bit of insomnia at the moment and thought I'd throw out some brain storming ideas.

- - - Updated - - -

Have you checked the oil filter o-ring? Is it possible that you left the old o-ring on the motor? Of course, this leak would be the front of the motor, but maybe enough is being blown into the k frame and getting to the rear?

 

[rolling_Thunder]

The places to look - start at the top.... oil flows down so the highest point you see oil is usually the problem....

Check the top rear of the block for the oil galley plug and the oil pressure sensor leaking (common problem i've seen) - after that your most common leak would be a rear mean seal....

things like leaking head gaskets simply weep... not enough to loose 2 qts that quickly IMO

 

[2059]

Had a similar thing happen to me. Turned out to be a cracked nipple on the factory style sending unit that finally let loose. Luckily I was in the shop finishing up some of the tuning when it happened. scared the crap out of me; a couple puffs of smoke when the drips hit the headers then BAM!!! You'd have thought someone set off a smoke bomb!. Check the easy stuff first. As mentioned, Filter gasket, oil sending unit. It's unlikely the read block plugs failed or rear main. Also keep in mind since it happened while you were driving if it was the Oil Filter you'll have it everywhere from the K-Frame to the rear end. If the sending unit, likely from the bell housing back.

Good Luck. Keep us posted.

Also, if it is the sending unit and you try to remove and twist off the nipple in the block, don't freak out. It will come out easily with a small "Easy-Out".

 

[6D5]

Found issue. Oil coming from Autometer electric sending unit. I put fresh oil and a new filter, cleaned all oil areas with brakeclean and fired motor. I saw the leak immediately with a bright flashlight seeing the area. Leaking from electrical post on top of sender, running down side of bellhousing and dripping from bottom of bellhousing . I was frustrated last night (happend yesterday) and thought oil was from under the engine area....NOT ! Thanks for all the replies. I will remember to always start from top when looking for leaks.

 

[Cranky]

In the mid 70's I bought a really nice 69 Dart with a 318 auto ac and ps for dirt cheap because the owner thought the rear main seal was leaking and didn't want to mess with it. Turned out to be the factory oil pressure sender so for a about an hour of time looking for the leak and fixing it, I had a nice car for a few hundred bucks.

 

[HT413]

Found issue. Oil coming from Autometer electric sending unit. I put fresh oil and a new filter, cleaned all oil areas with brakeclean and fired motor. I saw the leak immediately with a bright flashlight seeing the area. Leaking from electrical post on top of sender, running down side of bellhousing and dripping from bottom of bellhousing . I was frustrated last night (happend yesterday) and thought oil was from under the engine area....NOT ! Thanks for all the replies. I will remember to always start from top when looking for leaks.

It's always nice when the cleanup takes longer than the repair. Congrats.