Little oil drops...

[.Max.Power.]

Hey folks,

my CUCV is loosing oil. Very, very little, but I guess its not supposed to be like this. We are speaking of 5-10 drops per day. I found the hole where it comes out (don't even know why there is a hole). When I wipe it off, there is even no oil comming afterwards, as it is very, very little. Neverthelss, after a few hours I have some oil drops on the floor.

Any ideas how I can stop that?


Max

 

[chevymike]

That is a drain hole and should be there. Typically if dripping from there, it would be the rear main seal is leaking. This hole allows it to drip out so you don't fill the area the cover is, full with oil. Typically rear mains will leak while the engine is running and once off it will stop leaking past the seal. Once any excess oil has dripped out, it won't drip until you run the engine again.

The fix it to replace the rear main seal. It could also be the back of the oil pan gasket leaking.

 

[.Max.Power.]

That is a drain hole and should be there. Typically if dripping from there, it would be the rear main seal is leaking. This hole allows it to drip out so you don't fill the area the cover is, full with oil. Typically rear mains will leak while the engine is running and once off it will stop leaking past the seal. Once any excess oil has dripped out, it won't drip until you run the engine again.

The fix it to replace the rear main seal. It could also be the back of the oil pan gasket leaking.

I guess I will replace those seals then, but doesn’t seem to be urgently if I see it correctly.

 

[ehuppert]

When we used to run these over the road at high speed (when almost new) these ALWAYS leaked a little oil. And, seemed like the faster you went the more they leaked! Maintenance section used to get pretty pissed seeing the puddles!

Yes, it's the main seal! Is it critical? Probably not unless you run it low!

With vintage British vehicles which also always leak it's called rust prevention!

Eric

 

[cucvrus]

It can also be leaking higher up in the engine. The valley under the intake has a hole in the rear and that is directed into the bellhousing rear of engine and that hole is where you will see a leak. The oil leak coming from higher up can be a vacuum pump seal or the vacuum pump itself leaking. Also the oil pressure sending unit can leak and cause the oil to drip down. Valve covers anything that leaks up top must come down. So before you dive into the rear main seal entertain the thought of checking everything up top. Fuel leak can make a nice oily mess as it washes the 35 years of grime and oil build up on the trip down thru the engine bell housing. Good Luck. But you are correct. It is a common issue and it is old enough to leak at the seals and gaskets all over. Good Luck. Proceed with caution, plan the work and discover the issue before going wild. Or just pull the engine and reseal everything.

 

[Sharecropper]

It can also be leaking higher up in the engine. The valley under the intake has a hole in the rear and that is directed into the bellhousing rear of engine and that hole is where you will see a leak. The oil leak coming from higher up can be a vacuum pump seal or the vacuum pump itself leaking. Also the oil pressure sending unit can leak and cause the oil to drip down. Valve covers anything that leaks up top must come down. So before you dive into the rear main seal entertain the thought of checking everything up top. Fuel leak can make a nice oily mess as it washes the 35 years of grime and oil build up on the trip down thru the engine bell housing. Good Luck. But you are correct. It is a common issue and it is old enough to leak at the seals and gaskets all over. Good Luck. Proceed with caution, plan the work and discover the issue before going wild. Or just pull the engine and reseal everything.

Ditto what Rick said. It’s a 36 year old engine so it’s bound to leak somewhere. Hail I’m 70 and I leak.

 

[dougco1]

It can also be leaking higher up in the engine. The valley under the intake has a hole in the rear and that is directed into the bellhousing rear of engine and that hole is where you will see a leak. The oil leak coming from higher up can be a vacuum pump seal or the vacuum pump itself leaking. Also the oil pressure sending unit can leak and cause the oil to drip down. Valve covers anything that leaks up top must come down. So before you dive into the rear main seal entertain the thought of checking everything up top. Fuel leak can make a nice oily mess as it washes the 35 years of grime and oil build up on the trip down thru the engine bell housing. Good Luck. But you are correct. It is a common issue and it is old enough to leak at the seals and gaskets all over. Good Luck. Proceed with caution, plan the work and discover the issue before going wild. Or just pull the engine and reseal everything.

I would have bet the farm on a rear seal leaking on my M1009 a few years back. Turned out to be a cracked injector line at the injection pump that ran fuel down the valley and mixed with the oil buildup like cucvrus mentioned.

 

[MarcusOReallyus]

Five to ten drops a day?

I wouldn't even be thinking about it.

 

[Recovry4x4]

I'm glad I looked at the pictures. In the text I thought you said 510 drops. Was thinking, that guy has lots of patience.

 

[dougco1]

Five to ten drops a day?

I wouldn't even be thinking about it.

But if left "as is" to drip it acts as a "Poor Man's rustproofing" when driving down the road. I noticed my oil/fuel leak would leave small oil stains on the rear bumper and tailgate surfaces after a short drive. It also kept the weeds from growing wherever I parked.

 

[Garagefull]

Check your CDR valve to be sure that crankcase pressure isnt forcing your small leak.

 

[nyoffroad]

Check your CDR valve to be sure that crankcase pressure isnt forcing your small leak.

Good idea, also what oil viscosity is in it? I tried running a pure synthetic and a very small ream main leak turned into a smoke screen at 55+ (I lost a significant amount of oil). I went back home and swapped out that oil with regular 15-40 and went right back to a drip here and a drop there. Just a thought, YMMV

 

[DeadParrot]

2nd the thought to leave it alone for now. I would do the checks for leaks higher up on the motor. If the leak turns out to be rear seals, just add to the 'to-do' list if you ever have to do other work on that part of the motor. You can buy a lot of oil for the price of a pan gasket and rear seal set.