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AMC V8 Oil Leak

Jeeper_4_Life

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Has anyone had an AMC V8 hemorrhage oil at the top of the timing cover distributor area and run down driver side of the front of the block? Not a drip a lot of oil enough to pool in the valley of the timing cover. I can crawl all weekend no issue, drive 20 mile trip or less at 60 mph no issue. Drive 50 miles 65 mph or so for sustained RPM and it will leak everywhere?

Thought it was intake at first as I had some other issues going on, so took it apart and resealed it. That didn't fix it so I took front of motor apart a couple of months ago, resealed timing cover, new front seal, speedy sleeve balancer, new gasket on distributor to timing cover, resealed valve cover. First time I got to drive it a ways was this morning and it leaking like it had before.

Is it possible that oil can run up the distributor and out the cap? The bottom of the distributor is wet. I don't I am at a loss at this point of where it is coming from. I did the die checks before taking motor apart and it was hard to tell when everything glowed on that side, plus the AMC paint doesn't help with the color.

Hoping someone else has had this issue and can point me in a better direction.
 
After calling DUI and reading on their website it sounds like crankcase pressure is driving oil up through the distributor. I guess I will put some breathers in the covers to see if that helps. The motor was rebuilt years ago and installed for the first time 4-5 yrs ago. Perhaps the rings didn't seat well, or that is the nature of the beast?
 
I think a crank case breather will solve your problem.

No rings will seal perfectly, and I think your engine is probably in good shape.

Stop and go driving leaves plenty of time for pressure to seep out here and there, but prolonged driving just causes the pressure to build up.

In my neck of the woods, a pcv system is mandatory, so I haven't experienced that particular problem.
It sounds to me like you have a very well sealed engine! :cheers:
 
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I've never experienced that on any of my AMC V8s. They are vented, not only with a PCV valve, but from the oil fill as well. I've had a little oil accumulate right at the distributor, which I've always attributed to the little paper gasket for the distributor.

What oiling mods (if any) did you do to the engine?
 
So I found out last night my buddy who was helping me a couple of weekends ago used my oil filler breather as a crutch and pushed it down farther over the tube (it is open element crank case breather over the fill tube). I took it off last night to see if it had suction at idle, and when I went to remove it I had to lift it a long ways off the tube. I did not pay attention to how far down it was exactly, but it is possible it was sealing off the tube and not letting it breathe. I haven't driven yet to see if that helps it or not. I will find out tomorrow. I am still going to put breathers in the valve covers.

PCV seemed clean and free when I did the intake. No oil mods are done to motor other than BullTear mid plate on the pump housing.

It is either coming from valve cover, distributor gasket, distributor, or timing cover in that area.

The distributor thought came from this info I dug up yesterday under topic #4. The bottom of distributor is wet along with some under the cap and where the wires come out of the distributor.
http://performancedistributors.com/professional-tips/
 
Made a tool to extrude holes into my valve covers for the rubber breather grommets. Need gaskets to finish it and then hope it helps.
 

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Update on this.
Breathers didn't help, still puked oil everywhere and filled up the valley on top of the timing cover. So the two trips to work which is around 200 miles puked a quart of oil out.

One of these three things I did fixed it for now as after doing this it was completely dry making the same trip to work on Friday.

1) So based on performance distributors website and calling and talking to them, I drilled holes in the bottom of the distributor housing below the timing cover gasket. I removed the gear and rotor shaft out of housing and drilled the two 3/16" holes 180 deg apart. The roll pin above the one hole helps hold that pressed on aluminum sleeve that I drilled through. That pin goes through the bottom bushing as well. So I set the upper hole below that bushing.

2) I didn't want to use a sealant on the distributor gasket, but I did anyway. I used permatex aviation sealant thinly painted on both sides of the gasket and set it in the timing cover. I did put the distributor in without this to see if it goes down all the way, and from what I can tell it did. The timing cover gasket is recessed so it is about impossible to tell that everything is full seated once the distributor drops in. That sealant doesn't ever fully dry remains tacky, but doensn't mean it won't be a pain to clean when I have to pull it out in the future.

3) Before taking it apart I checked the timing with a new fancy timing light I bought. It showed I had it set at 19 deg. I guess once you go past the 10 deg mark on the cover and trying to eyeball it, it doesn't take much to be way off. So when I put it back in I backed it down to 12 deg.

Maybe one of those fixed it or it took all three. All I know I was pretty happy when I made it home and it wasn't raining oil everywhere.
Breathers.jpgDistributor 1.jpgDistributor 2.jpg
 
If you're getting enough pressure inside the engine to force oil out the top end, then I'd do a compression check sooner than later. You need to figure out where the pressure is coming from. Maybe bad timing or it could be a bad valve/piston ring.etc... leaking combustion pressure back into the block.
 
19 degrees advance....did you have any detonation? Just a theory...but I suppose having been that far advanced, detonation could rock the piston and rings and cause excessive combustion chamber pressures pushing crankcase pressures up....
 
Compression gauge set is on my list to get here sometime.

I honestly do not know if it was detonating. You would have thought it would have been, but I do not recall hearing anything, but is a jeep and hearing the radio is a struggle going down the highway. It seemed to run okay, it may have just maxed out the total advance sooner? I'm not a engine guru so my knowledge is limited.
 
I have to ask, was timing checked with the vacuum line plugged (to distributor). On my cj7 with the chevy 350 I found the timing was 17 deg. Had no detonation. Builder put a cheap distributor in. Timing was bouncing all over the place. Mechanic installed better distributor. That much play in the distributor.
 
Advance was not hooked up when I set the timing. Vac advance hose was plugged off. Distributor is a DUI.
 
While checking timing slowly open your throttle while checking the timing. My timing wouldn't be steady at different rpm. Was told could be springs, bushings worn etc. Distributor was a cheap unit. Was easier to be sure and replace with new distributor. Mine was also 17 deg. at idle. Someone could have set timing incorrect or distributor worn out.
 
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