Question : 92 Cutlass Supreme 3.1 oil drive shaft o-ring leak

[snippits]

Have a 1992 Cutlass Supreme 3.1 MPFI. I bought it for $700, and it has a Jasper rebuilt engine with about 100,000 miles. It was a one owner driven by a woman, and when she died her husband let it sit for four years before selling it. He was not actively trying to sell it, but he said since I asked about it that it was time to let it go.

I have confirmed that the o-ring oil drive shaft assembly is leaking. It's starting to make a mess in the driveway, so it's time for me to take a stab at fixing it. I have an original 1992 Oldsmobile Cutlass service manual full volume(same as dealers used), and I could not find any repair and replace information in the manual.

Read a lot about replacing the o-ring, and there is conflicting information mostly regarding whether or not the upper intake/plenum has to be removed or not. My upper intake has the square look to it while the later models had the long runners some people call spider legs or what ever. I just need to know whether or not I need to remove the upper intake or not? Some say yes and others say no.

From just looking at it, it seems I could just disconnect the throttle body and the coolant hoses to throttle body, and there could be enough room to get it out of there without removing the upper intake. Money is tight right now, so if I can't get it out I was thinking about just raising it up enough to clean the area, and then apply some The Right Stuff gasket sealant on it, and calling it done. Not sure if it would seal the oil leak or not, but just thought this would be another option.

Let me know what you think, because the manual I have is not helping a bit. Thanks!

[Guest]

IIRC I was able to replace my O-ring on my gen2 3.1 by just removing the throttle body.

Using a silicone or other hardening liquid sealer in the way you describe will not work, or at least not for long. There is a good amount of pressure there and will easily push out any sealant you add there.

[snippits]

IIRC I was able to replace my O-ring on my gen2 3.1 by just removing the throttle body.

Using a silicone or other hardening liquid sealer in the way you describe will not work, or at least not for long. There is a good amount of pressure there and will easily push out any sealant you add there.

Good to hear. I can pick up the upgraded o-ring from the Chevrolet dealer in town. They have it in stock for $4.00. Will probably do the throttle body coolant hose bypass too while I am at it. I am really surprised at how much of a mess this little bitty o-ring is making!

[geoffinbc]

For insurance I would reinstall the shaft plug with the new ring and also RTV the under side of the top flange. This will just add another layer of sealing.

[snippits]

Got the o-ring fixed, and it's not leaking now. I did use the GM upgraded o-ring instead of the black Fel-Pro. Only had to remove the throttle body, the coolant hoses to the throttle body, and the fuel lines. Grabbed the lip of it, and it the shaft came right out easily. The black o-ring just crumbled into pieces when I removed it from the shaft. The shaft went back in surprisingly easy. Twisted and turned until it dropped down a notch. Twisted and turned again, and it dropped down another notch. Put the shaft hold down bracket on, and wrenched on the bolt, and the shaft seated right where is was suppose to be.

I was going to use a gasket and some sealer, but when I removed the shaft there was some RTV sealer already there which was not doing a dang thing to stop the leak, so I just installed the o-ring and left it at that.

The two throttle body coolant hoses were a pain to take off, but other than that it was an easy job. A seasoned mechanic could do this job in 45 minutes or less.

[hal.lyman]

This was the same repair I made last fall, my first effort since I was a teen to fix anything automotive (now 45). It took close to two months and without the help of the people on this forum I never would have been able to diagnose and complete the repair. My learning curve is tightening up and I have since changed transmission lines, fuel injectors, oxygen sensors and more, with increasing facility and speed. This forum and the people on it have opened the door to a great hobby that I'm really enjoying and is saving me money too! Thanks to all the active members who make this a great place to learn and share!

Sent from my SCH-I545 using Tapatalk

[geoffinbc]

If you just get the basics down like fluid changes and brakes you can save several thousand dollars during the life of the vehicle. My aunt just got quoted nearly a grand for the brakes on her Silverado!!! I can save her more than half while using much higher quality parts for the job.