Distributor Oil Leak..."call me crazy"

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mitch340Duster

mitch340Duster

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Fresh 340, new distributor. After high-idling for 30-45 minutes (but not before) I'm getting a steady oil drip between the engine/trans. Usual troubleshooting begins. Determined to be the dreaded "near the base of the distributor" leak. With the help of a cool "magnet on a gooseneck" from Harbor Freight, the leak has been proven to be coming from the bottom of the distributor housing. Not the mounting flange at the base where it mates with the block, but the dist housing itself. It is then dripping onto the mounting flange giving the appearance that it is coming from the intake / sender / distributor mounting area.
I read as many of the "distributor oil leak" posts that I could stand but so-far I seem to be the only one who has had this problem, so I'm hoping for a free FABO tee shirt or something.
Of course I need to pull and inspect the "dizzy" as another user calls it, but while I'm waiting for the motor to cool down I figured I'd throw this out-there since it seems unusual to me.
Thanks for listening.
 
Do you have this engine properly vented and with a PCV valve too?
 
I saw PCV mentioned in other posts. To the best of my knowledge/research, the engine is setup "correctly" with the correct breather for the ECS system and a PCV valve, see pics.
Oddly though, I also had a persistent oil leak at the RR valve cover. Tried the expensive Mopar gasket and I think that took care of it but now this leak is encroaching onto that area too so it's hard to be sure.
I suppose I should run it one more time maybe without the breather and PCV to rule-out any strange problem with the system, so thanks for the reminder on that.
Will look again this afternoon.
 
Don't have a small leak at the oil pressure sending unit, possibly squirting oil up onto the dizzy, do you?
 
A leak in that area is almost always 1 of 2 things...

1. Intake gasket popped back by the distributer. This is usually caused by too much internal pressure (like what RRR was referring to with the PCV valve) or a slipped gasket. Simple fix, remove intake, re-install without the end seals, just use a bead of RTV on the ends.

Or....2. Oil pressure sending unit leaking.

There is an o-ring on the base of the distributer as well (where it meets the block), but oil does not go in or out of the distributer, so oil cannot be coming from it.
 
Is the distributor seated completely on the block? I recall someone having silicone that had oozed out from that manifold end seal drying on the block. Then when they put the dist in they did not notice that part of it was sitting on top of that silicone blob.
 
Those pictures are nice, however are not close enough to help with this issue....
 
OK - you're crazy... :)
What distributor are you running? Can you actually see the leak, or you stuck a magnet back there and it got oil on it?
 
1st of all guys, I'm not looking for someone to do my troubleshooting for me (I know nobody's suggesting that) but after Mopers post now I'm sure that this is an interesting topic and that's why I posted it. (Moper, it's a MP dist from an electronic ign conversion kit).
Even though I was 100% sure this morning, you guys spooked me so I did the same thing again. Earlier, the right side breather hoses were DC'd but the breather and the PCV were still installed in the valve covers. This time I removed both the breather and the PCV from the valve covers so the engine was run with open holes in both valve covers. I also found at this time that I have good vacuum coming from the PCV hose and the valve is free. Krazy, I know those pics don't show much I just wanted to at-least show that I had some kind of vent system installed since I know everyone thinks I'm nuts by now.
I'm telling you with 100% certainty that oil is dripping from a hole in the bottom of the dist housing. I know about phantom leaks that start elsewhere and migrate to the area in question but this is not the case. With the mirror, flashlight and magnifying glasses I have a PERFECT view of it but no way to photo/video it. I can even see the plate or whatever rotating inside the "dizzy" through the 1/8"-ish hole. A shot of brakekleen, blast of air will clean the area nicely. With gauntlet gloves I'm able to hold the mirror and light and watch carefully as oil drips from the hole with everything around it clean. In-fact, the mirror is positioned directly below the hole, but above the top of the block, and the oil is dripping right onto the mirror glass !
after another cool-down I'm gonna pull the dist and see what I can find.
One question though, is there still any possibility of a pressure problem even with the breather/PVC removed? I did have that VC leak too but it's in a spot that a lot of guys seem to have trouble with, and there have been no other oil leaks.
I swear, the strangest things happen to me..
 
I should add that the leak is appearing in as little as 10 minutes now, not the 30-45 I said before. It has to be a bad seal or a crack or something that is allowing splashed oil to get up in there somehow through the shaft. I will report back.
 
Ok - I was just checking to see if it might be something else but you're saying you can see it out the weep hole. Normally there is not enough crankcase pressure to push the oil up the shaft and into the distributor body. that hole is more for venting and water if it was ever to get any in there through condensation, etc. Is there any oil coming out the dipstick tube with everything disconnected? Does the handle get pushed out of the tube? With everything reconected - pull the oil fill cap - when it's running do you see any oil vapor coming up from the valve cover? Put your hand over the fill hole and rev the engine slowly to 2-2500. Do you feel pressure pushing your hand off?
 
Where is the hole in the distributor that the oil is coming out of?

Is is supposed to be there, or is it porosity/corrosion related?
 
Moper negative on all. No vapors, no resistance at-all with hand over the oil fill, no other oil leaks except that valve cover, and I don't think that's leaking anymore.
I pulled the dist and inverted it to drain the oil from it (seriously). I see no obvious problem.
I remembered that my old van has a similar dist so I pulled it and put it in the Duster and it started so tomorrow I'll run both vehicles and see what happens. There is a design difference between the 2 that could explain it and more shaft play on the Duster dist but the whole thing is still pretty strange.
KK, the holes are supposed to be there. The van dist also has them. Stay tuned.
 
What is your oil pressure running?

If the oil plug under the distributor by the oil pump drive is missing it could be spraying enough oil on dist shaft the it comes out the dist hole.
 
Sounds like a good test. I think the distributor is the problem - does it have the thin flat washer above the nylon collar on the shaft at the base of the body?
 
I had the same problem with a brand new FBO dizzy. When I called them up I was told something was wrong with my engine, like excessive blow by etc.
There are two bronze bushings inside the housing for the shaft to ride on. Oil splashes up the shaft to lube the dizzy and is supposed to drain back into the engine thru drain slots between the housing and bushing. If the upper bushing is driven to far up, the lube oil cannot drain back into the engine. Oil collects and finally comes out the vent holes.
Back in the day you could buy dizzy shaft bushings at any mom and pop auto store and rebuild your own stuff.
Quality Control sucks in this world we live in. The new FBO dizzy I had oil venting problems with went in the trash can. MP stuff is made by the lowest bidder and is no different.
 
I had a distributor do that to me too! It was one of the HEI conversion types from ebay. the oil would travel up the shaft and leak out everywhere, Fast. They told be they got a bad batch of distributors where the bushings and seals were not installed properly. I sent it back ang got my money back.
 
+1 on all that. The lower part of shaft has a spiral cut that takes oil up. Something wrong with upper bushing, loose or wrong height.
 
OK the results are in. I put the van dist in the Duster and ran the car for close to 2 hours with no leak at all. Unfortunately the Duster dist, when run in the van, did not leak so I can't positively blame the dist exclusively for this. Maybe it's a combination of the dist being a little messed-up along with whatever else may be going on in the engine like oil pressure or even the way the oil splashes around in there.
I'm gonna look for another dist for the Duster and hope it works OK. The van dist has a different "collar" than the duster and also less play in the shaft. The collar has a flange on it that could be blocking the oil from getting up in there. I suspected when I saw it that this might solve the problem. Duster does not have this flange. Van dist with flange is like the inset one in the photo. What an irritating little problem. Got several hours and prolly close to 100 dollars in fuel into this thing, but thankfully I'm pretty-sure this is the last of a series of difficult fluid leaks on this newly assembled car (none of the others are related to this) Thanks for everyone's help and input.
BTW that friggin' '79 Dodge Van I've had since 1987 is still the best vehicle I have ever had.
 

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Easy fix, the bushing on the end of the distrubutor shown above is broken. Someone replaced it ghetto style. Find another distributer at the junk yard and remove the bushing and replace it. should fix the issue... or solder a small tube to the weep hole, run some rubber hose back to your oil fill cap, and let it drain back into your engine (sarcasm)
 
Vipe the dist in the picture is not broken, and I bought it new. Some of 'em have that flange and some don't. Luckily the Cardone Select that I ordered does have it so I'm thinking I'm all-set, just haven't installed it yet, and I don't intend to run the car another 2 hours to find out. I'm confident it'll be fine. In-fact that picture is not even my dist, it's a pic I stole from the net.
The rubber hose trick would have been pretty cool though.
 
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