I ordered a new opti, and I was doing some research on the replacement process. Along the way, I found some people that were saying to take apart the opti, threadlock the rotor screws (never a bad idea), and then seal it up with RTV when done. I also saw some info that said not to do that because ionization may be an issue. Honestly, I like the idea of sealing it up, and it's a vented opti ('95), so would I be wrong in thinking that ionization/corrosion won't be a problem because of the venting?

 

Ozone is very corrosive. If you look at the design of the opti, fresh air comes into the optical encoder side and exits at the distributor side with the attempt to try and keep all ozone out of the electronics side.

Use as designed.

 

Since the 95 has the vent system, it would seem that "sealing it" would not affect the presence of ozone.

 

Is that only on the non-vented opti's?
Injuneer, would I be correct in my thinking then that the venting would bypass this issue? I only ask because it would be nice to eliminate as many points of failure as possible.

 

i did a cap and rotor this spring on my 97 vented opti (april) and i sealed the entire unit using GOOP and threadlocked the rotor screws. I drove the car all summer over 5000 miles with not a single stumble or missfire

 

agreed

 

GM specifically added the vent system to eliminate the ozone problem. The vent removes ozone, which is caused by the high voltage discharge in the cap. I'm not sure what you mean by "bypass the issue"????? If the Opti is assembled correctly at the factory, it is sealed correctly, and the only way for the ozone to be removed is via the vent system. His "sealing" would just be to correct a possible factory error.

Beyond that, your post totally confused me.

 

Sorry, what I meant was that with the factory venting, the ozone problem would go away. With eliminating points of failure, I just meant to remove a potential problem such as moisture or condensation buildup inside of the distributor. That's the entire reason that I was exploring the option of using silicone to seal the parts together.

 

Moisture is a separate problem. In addition to contributing to carbon tracking, it also causes rust, which can blind the optical sensor. Sealing it is probably a good idea.... keep the moisture from getting into the unit in the first place (if the factory seal is defective).

Keep in mind that the Opti is dealing with close tolerances. Too much sealant, and you increase the spacing between the rotor tip and the cap buttons.

Note that the main source of liquid entering the Opti seems to be a poor quality seal in the "tower" for the harness connector. Be sure to seal that as well.

 

Want to do a test before installing vented opti? use a suction sorce on the nipple that connects to the intake manifold and apply finger on the other nipple which goes to the intake elbo. If you can't feel the suction then you have a leak.

 

I'm suprised I haven't heard of more people doing what I have done. It seems, at least with all the experience I have with my car before I even got it while my buddy still had it. He had a leaky water pump that eluded him for ages and kept taking out the opti. So what I did was cut a small piece of steel brake tubing and installed it in the weep hole about a half and inch with a bit of sealer around it. then I used a punch and staked it in so it wouldn't come out. I then used that as a nipple to put a piece of washer hose on to direct any future leakage away from the opti if the new pump starts going south.

 

That's actually a pretty good idea. I may do that, since I'll have everything out anyway, thanks for the info on that.
The other reason I wanted to seal the opti was to protect it against other moisture ike water from a large puddle or a car wash. Mine has held up to tons of abuse, but it's 15 years old with 104K on it, so I figure it's time.