So, at the end of February, I decided to pull my distributor to change the o-ring. I was getting a slight oil leak down the back of the motor. I had bought a Box-Of-O-Rings at the Englishtown swap meet last year, and figured I'd use an o-ring from the box.

The 3rd week in March, I'm driving, and I smell burning oil. I look up, and my oil pressure gauge is at zero! Luckily I was 100 feet from my house; I just shut the motor off and coasted into the driveway. I checked the stick; took 2.5 quarts of oil to put the oil back at the bottom of the stick! So I was really low on oil!

Checked it the next day; added enough to get me to the full mark. Started the motor, a few seconds later, I saw blue smoke from the back of the engine. I looked underneath- oil was pouring out of the motor!

So I pulled the distributor again. O-ring was fine. I put the distributor back in, started it up- same thing. No wonder my oil pressure dropped so suddenly; I may as well have been pouring oil from a bottle onto the ground!

So I pulled the distributor Again. I changed the o-ring. All was OK until yesterday...

Went for a drive during lunch. Came back, smelled burning oil! Looked underneath the car (with the motor running), and saw oil dripping - but not pouring - out from behind the motor.

I went home, and decided to dig up the bag of o-rings that I bought at Pep Boys a few years ago. I Finally found it (an hour and a half later), and compared it to my Box-Of-O-Rings.

The o-ring from the bag was THICKER than the o-ring from the box!!

So I got out my dial calipers. The o-ring should be 1 inch inside diameter, 1/8th inch thick. That's 0.125 inches.

The o-ring from the box was 0.123 inches thick.
The o-ring from the bag was 0.138 inches thick!!

Plus, this time, when I put the distributor in, I really had to push HARD on it to get it to seat into the intake manifold. With the cheap o-ring, yeah, I had to push a little bit before it dropped in- but with the real o-ring, I had to push HARD.

Attached is a picture of my distributor (left side) with the cheap o-ring installed, compared to a junkyard distributor (right side) with a "real" o-ring installed.

So beware the box-of-o-rings!! Apparently $10/box was too good to be true.

 

When I had my distributor out recently to replace the O-ring, I used a FelPro O-ring from the parts store. I also used a FelPro distributor gasket ment for a small-block for added insurance against a leak. It's been working great so far.

 

Tom, A little trick to help prevent leaking is to also dap some bearing grease on the shaft over the o-ring and also on both sides of the base distributor gasket.

My biggest leak problem area is the damn pressure sending units. I go through them about 1 per year. I have an A/C Delco unit in there right now only about 8 months old that just started leaking onto the y-pipe again (no, I am not screwing them on from the top with a wrench and losening the pressed together seal. I am tightening them on from underneath next to the threads into the block)

 

Ah, the distributor o-ring... Where to begin. when I went to replace my ignition module, (remember the car was shutting itself off in traffic), the wiring connector for the pickup coil disintegrated in my hand-(Tom, KED, Doward, you guys were right!) After reading the distributor rebuild posts I decided to pull the thing. Brought number one to TDC, marked everything, removed the hold down clamp and bolt, and guess what, it's stuck! No amount of pulling would free it. Finally did some more research and found that the o-ring seized to the block. A little brake clean and some WD-40 down the crack where it goes in the engine , and out it came! Once I got the distributor on the workbench I noticed that the o-ring was thicker than anything I had on hand, so I ended up ordering a pack of them from GM: part number 10477565 $1.04 each, five to a pack.

 

Wow, thanks for the part # of those o-rings! I'm about to order 20 packs!

I couldn't believe my box-of-o-rings is worthless. The thing has a ton of sizes in it; past anything I thought I'd ever need. I guess it'll be good for something; but now I just don't trust it. I guess if it's a non-pressurized area, I'd use one of them... but I'm contemplating just throwing it out so it doesn't take up space.

I never had a problem with the o-rings leaking (aside from this cheap 0.123 diameter one) before... thanks for the tip, RTFC! Is the grease just to prevent the o-ring from getting sliced on the edge of the intake manifold, or does it help condition the rubber against aging?

LG, I remember reading how Karl (KED85) said a SBC dist gasket would work; does it matter which year? Or would I just go to a store and say "hey I need a SBC dist gasket" and they're all the same? Or is it different based on the motor's size (327/305/etc)? Plus, what do they look like anyway? Is it something I could just cut out of gasket material?

I'd just hate to wind up in another situation where I can't find the correct o-ring and need to get the dist back in; I should pick up a v8 dist gasket just as an emergency backup- that's assuming I could find it when I needed it, tho. (laughs)

Hey I was trying to find an online picture of what I bought; looks like this is the same kit: http://cgi.ebay.com/ws/eBayISAPI.dll...374565995&rd=1

I also found a wild website for o-rings... http://www.marcorubber.com I wonder what kind of quality their stuff is compared to the stuff I got.

 

Yeah, the distributor o-ring may be small, but its repsonsible for a lot of problems! May as well use the factory part and play it safe.

 

Ya know, I don't remember what it looked like. I walked into my usual parts store and asked for a SBC distributor gasket when I got the O-ring. I had never seen one either, or knew what to expect, or if it would work.

I think they're all the same...nobody asked me for specifics when I asked for a SBC distributor gasket.

I'm sure you could make one your self from gasket material. The gasket just slides on to the distrib. before you put it in, and ends up sitting sandwhiched between the distrib. and the engine. Just need to get the hole the right size. You could propbably use the O-ring to get the diameter.

 

^^^^ Karls gonna be angry that you mentioned the sbc gasket before he did

I got mine for a 1980 comero w/v8. Fit perfect.!!!! $0.79 at AZ.

 

LOL!! Sorry Karl!!
I have to give credit where it is due though, I got the idea from him! I never would have thought of it.

 

It's just a big ring! I cut one out of gasket material. A WD-40 can cap is the right size for tracing around to cut the hole.

 

I'm glad my tip has lived on!
Here's all I can say
Dean is 100% right in that ya lube the o-ring to slip onto the shaft & also "seat it" in the hole (no porno talk here folks!). The oily film "dries out" due to engine block heat.
Before ya reinsert the Distb. also clean inside the hole, with a white papertowel, making sure ya get rid of any previous o-ring residue left over.
Small Blcok Chevy Gaskets.
I once tried to make one.
I failed, as I could not cut a clean inner circle. I ended up with a choppy cut that also leaked in end.
After I bought the right part, at $1 and the problem was solved.
IF I am correct, I did not add a o-ring to my distb. when I did the 3.4 swap. I only used a small block chevy distb gasket coated with film of Black RTV solution, both sides. And I also let the project cure overnight. Haven't seen a problem since.
I now also suggest using the o-ring (it's cheap, why not!) and also the small block chevy gasket together to assure (hope for!!!!) no true possibility of leaks.
What is a small block chevy gasket?
I'm familiar with small block chevys (of 1955-1980's) and in line 6 cylinders (same vintage). The "part" seems to be identical in both applications, all those engine years.
IF ya wanna feel special (!!!) specify a small block chevy gasket for a 1970 Corvette 350 LT-1! engine. It'll be same as a lo-po SBC gasket called out for a 1982 305 TBI!
It's a great real world working solution.
No complaint of others stealing my tips, happy to pass along the smile of job well done. Beside it's more fun to hang with cute women than oily greasy car parts anyday!

 

Redraif's car has an issue with Oil pressure sending units also...we've probably put at least 3 on the car over the last couple years. One of them blew out on the dyno, the other two in normal driving (well, normal for her... )

 

i was going to do an ignition rebuild here in a month or two. and was doing some reading up (how i found this thread) i have had a small (drip every few days) oil leak on the back of my engine since i purchased the car. after reading this i am almost posative that is what it is. i do smell it burning everyonce in a while. i am going to have to bookmark this thread.

 

A good source for quality distributor O-rings is Rodney Dickman (his site is http://www.rodneydickman.com)

His are supposedly a special rubber such as Viton which is supposed to last better in the high-heat environment of the engine.

 

If you guys ever get a really bad oil leak (pouring) from the rear of the engine, or if you happen to have your tranny out for service, go ahead and replace the rear cam seal (the dealer has it, most parts stores don't). People complaing about leaking rear main seals, this is the worst leak you'll ever get on a 60 degree V6! It dumps oil like someone pulled the drain plug almost!

 

I HIGHLY RECOMMEND REPLACING THE REAR MAIN SEAL AND REAR CAM SEAL!
I STOPPED MAJOR LEAKS WHEN I REPLACED MY REAR CAM SEAL!!! LAST TRANNY SWAP JOB!!!
YEP DEAL ITEM FEW BUCKS PLAN FOR THIS JOB!!!!!
IT REALLY IS MANDATORY!!!!!
NO OTHER WAY TO REPLACED BOTH THOSE ITEMS UNLESS TRANNY IS OUT!!!!