Lovely oil leak

[TechnoWeenie]

6.2 gods, lend me your ears...



I got an oil leak...it's been leaking but since I don't drive it much I haven't delved too far into it. We are talking a quart every 100 or so miles. Enough that it's idling there will be a couple drops in 5 mins or so. The oil hasn't been changed because it's been sitting. But I have driven it probably 500 or so miles and the leak hasn't changed and it's been sitting for 2 years and still no change in oil consumption.

I cleaned everything and dumped dye into the crankcase...


Using my black light...

From above, there is nothing visible.. So, that would seem to rule out valve covers..

From below


There is a little bit of oil on the oil filter and around the oil filter mount, and even on the driver side spring. But those are low points, and I didn't check the spring to see if it was oil, I just noticed it was fluorescing under UV light.



So....

Possible issues..

Oil filter or Oil filter mount
Rear main seal (? Isn't that lower than the oil filter?)
Oil cooler lines
Oil pressure sender(?)

I thought the rear main seal was too low and not in an area that would put oil in the area that oil is, please correct me if I'm wrong.

I would also think that oil cooler lines and the rear main seal would get worse as time and mileage accumulates, so it would seem to me that it's not one of those.

That would leave the oil pressure sender and either the oil filter or oil filter mount.

I will be taking it to a shop shortly because I do not have a lot of time to work on it, but I'm trying to get a an educated guess and a consensus of what is most likely wrong.

 

[Bighorn]

Pressure wash it.
Carefully of course.
Whenever i go after a leak of unknown origin, i spray the engine down with foamy engine bright, let sit for an hour or 3 beers, then pressure wash.
Fire it up and inspect.

You'll find it for sure.
Any pictures?

 

[olly hondro]

Could just be the CUCV marking its territory...they are like that

 

[Bighorn]

Could just be the CUCV marking its territory...they are like that

That's a jeep thing..

 

[cucvrus]

I would go as far as checking the vacuum pump also. I had one leak out of the pump itself. But the rear main seal is my next guess and that would be higher then the oil filter. Good Luck. Remove the flexplate/flywheel/converter cover and see what is inside that.

 

[ken]

A quart in 100 miles. There should be oil everywhere. I little leak when blown around by the fan can look huge. Have you looked in the rad? Any oil in the coolant? CRD valve bad? Letting all the blow by drawn into the intake manifold? Remove the air cleaner. There should be some oil in the intake. from the CRD, but if it's a quart in 100 miles the intake would have liquid oil in the intake. Also look at the cover on the torque converter. There is a drain hole, is it plugged? If so clean it out. If motor oil comes out it's the rear main.

 

[DREDnot]

Oil on the drivers side spring leads me to believe that its the oil cooler lines. They start by seeping around the metal to rubber crimps and will drip on the drivers side shock and spring.
I had the vacuum pump leak like CUCVRUS mentioned and it dripped down the passenger side of the bell housing looking like a bad RMS

 

[frank8003]

Just get the Dawn and a squirt bottle and have at it.
Squirt everything. then take your 79 buck HV pressure cleaner to it all over the place.
Then the Dawn and the PC.

Won't hurt a thing.
Gee, we did this with old 55 Chivies without the HF stuff and the Dawn.
Did it by hand back then......................
Has something changed?
Just clean it, run it, look at at.

 

[Ilikemtb999]

I chased an oil leak for a while. Ended up being a rear main and pan combo. Also replaced the front crank seal and tomingcover while I had it apart. Mine showed mostly on the starter and out of the inspection cover hole for the trans.

 

[Drock]

A quart in 100 miles. There should be oil everywhere. I little leak when blown around by the fan can look huge. Have you looked in the rad? Any oil in the coolant? CRD valve bad? Letting all the blow by drawn into the intake manifold? Remove the air cleaner. There should be some oil in the intake. from the CRD, but if it's a quart in 100 miles the intake would have liquid oil in the intake. Also look at the cover on the torque converter. There is a drain hole, is it plugged? If so clean it out. If motor oil comes out it's the rear main.

Agreed, perfect answer

 

[TechnoWeenie]

I chased an oil leak for a while. Ended up being a rear main and pan combo. Also replaced the front crank seal and tomingcover while I had it apart. Mine showed mostly on the starter and out of the inspection cover hole for the trans.

One of the reasons I parked it is oil got into the starter and borked it, I had to replace it...


Had the radiator replaced too...

 

[Bighorn]

One of the reasons I parked it is oil got into the starter and borked it, I had to replace it...


Had the radiator replaced too...

No way.
Your starter quit because the battery terminals corroded.
Or some other reason.
Oil ain't gonna do it.
Plenty of Mexican owned Chevys have lived hundreds of thousands of miles leaking oil onto their starters.
What you need to do is; drive it.
Every day.
Take it to work and back.
Go get icecream in it with the kids.

I have seen this before.
A parked rig rots faster than a daily driver.
Also less maintenance.

Make that your baby and the problems get handled.

 

[TechnoWeenie]

No way.
Your starter quit because the battery terminals corroded.
Or some other reason.
Oil ain't gonna do it.
Plenty of Mexican owned Chevys have lived hundreds of thousands of miles leaking oil onto their starters.
What you need to do is; drive it.
Every day.
Take it to work and back.
Go get icecream in it with the kids.

I have seen this before.
A parked rig rots faster than a daily driver.
Also less maintenance.

Make that your baby and the problems get handled.

I was there when the shop rebuilt it, and watched as everything had a nice coat of oil on it...


Rebuilt starter.... couple months later it stopped....went to the shop and the guy wanted to charge me for the second rebuild because it was soaked in oil and shorted out, so he said, and as mentioned, I was there when he pulled it apart and oil was everywhere....


This is a very well known shop that does alternator/starter rebuilds, and that's it.... Not that they can't make a mistake, things happen, but it was coated in oil....insides too.

 

[Bighorn]

I was there when the shop rebuilt it, and watched as everything had a nice coat of oil on it...

As have many millions of GM starters and worked just fine.
My solution still stands.
A lot of folks buy these rigs and park them.
Expect them to start months later.
My Dad did that with Desotos and Fords.
They will rot treated that way.
You have to drive them.
That was their purpose.
WAAM in Oregon drives, flys, or operates their museum pieces for the same reason.. including the Jenny.
If you won't drive it, consider selling it to someone who will.

 

[Tinstar]

Agree that sitting like that probably caused the problems.
If you don’t exercise and heat up the seals, they tend to shrink and get stiff.

Happens everyday, from custom car folks to MV folks.
Don't drive enough or rarely at all and it will go to pot on you.
Seals, fuel systems, etc.

I drive mine daily with very few exceptions.
Zero leaks. Anywhere


Sounds like your past the point of no return, and depending on what you find, lots of work and $$ will be involved.

 

[Drock]

Well if as you say your losing a quart every 100 miles, and the starter is full of oil. Then the logical answer is the 30 year old rope rear main seal is leaking. I would just change it regardless, and check it off the list of leaks you'll be chasing anyway. As Bighorn said sitting rots seals & soft parts and that's the main problem with CUCV's. Their all low miles 30+ year old vehicles that sat out in parking lots waiting for the big one. Thus the solargizers mounted on the hoods.

 

[TechnoWeenie]

As have many millions of GM starters and worked just fine.
My solution still stands.
A lot of folks buy these rigs and park them.
Expect them to start months later.
My Dad did that with Desotos and Fords.
They will rot treated that way.
You have to drive them.
That was their purpose.
WAAM in Oregon drives, flys, or operates their museum pieces for the same reason.. including the Jenny.
If you won't drive it, consider selling it to someone who will.

I was driving it, daily....

I stopped driving it because of the leak.....

 

[Bighorn]

Go buy a can of Foamy Engine Bright.. or whatever it is called.
Hook a hose up to the spigot on the base of your water heater.
Spray the engine down with the cleaner.
Let it soak.
Rinse with warm water.. also helps your water heater.

Then drink a beer.

Fire that pig up and lay underneath it until you see the oil leak.
Find the source.
Order parts and tools.
Fix the sombitch.
Drink more beer.

Really couldn't be easier.

 

[TechnoWeenie]

I was just trying to get an idea of most to least likely... It's at the shop now, guess we'll figure it out soon...

 

[antennaclimber]

I had the right side valve cover leaking on my M1008. It was leaking toward the lower rear corner. Never knew that it was leaking until I pulled the engine and found the oil was going down the inside of the frame.