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Discussion Starter #1
I've had a noise for awhile now that sounds like a vacuum leak but can only be heard with a load on the engine at around 2000-2300 rpm's. I have replaced EVERY vacuum hose and even all the evap hoses and solenoids and electrical switches (partly as a PM measure but also to try and find the issue). Well yesterday I believe I found the issue, I had my car up on a lift and noticed that when I replaced the distributor cap with an MSD cap the cap to isolator seal dropped out of position and the lower portion is hanging out the bottom of the cap. I can't repair it right away but just wondering if it would be a good idea to cap off the opti vent vacuum source at the intake for now and just leave the fresh air vent line connected? I should be able to get it repaired properly in a few weeks.
 

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Let's see. 50/50 that seal is fubared getting pinched, so you may elect to snip it and attempt some super tape to seal the housing in that area. Or, a bead of silicone between the exposed ends of that seal for the same purpose. The only limit to those approaches is sjit is dam tight under there for access. If you go that route, then best keep the harness connected. Some guys have painted on toolgrip dip over the whole distributor for a superseal too.
 

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Discussion Starter #3 (Edited)
At the moment I don't care if the seal is bad or not as tomorrow I'll call my buddy who works at MSD and have him send me some new seals. I'm more concerned about stopping the vacuum leak and if there will be any effects to the opti in the couple weeks leading up to the proper repair of replacing the seals and triple checking that it doesn't drop out of place again. At least this time around I'll start the engine first and pull the opti vent hose off and install a vacuum gauge to make sure there is vacuum verifying no leaks anywhere at the opti.

I can't see any harm over what potential it currently has.
 

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OP

If I understand your vacuum side on the cap broke for the vent line??

If so just cap off that line so the motor does not have a vac leak. The Opti is no longer getting vacuum to vent even if you leave the vent harness connected anyway.

With that said the Opti without working venting can quickly start to oxidize inside from the condensation that happens from motor heating/cooling. I have seen brand new dealer installed AC Delco opti die in less than 800 mi from a non operative vent harness. Had wet crud in it

I would get to the fix sooner than later
 

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Discussion Starter #5 (Edited)
OP

If I understand your vacuum side on the cap broke for the vent line??

If so just cap off that line so the motor does not have a vac leak. The Opti is no longer getting vacuum to vent even if you leave the vent harness connected anyway.

With that said the Opti without working venting can quickly start to oxidize inside from the condensation that happens from motor heating/cooling. I have seen brand new dealer installed AC Delco opti die in less than 800 mi from a non operative vent harness. Had wet crud in it

I would get to the fix sooner than later
Nothing broke. The distributor cap to isolator o-ring seal fell off on the bottom when I installed the new cap & rotor kit and I didn't realize it. That now creates a vacuum leak of the opti harness. I capped the vacuum source at the driver side intake for now but I still get a surging at idle which I now suspect is caused from unmetered air on the engine side of the MAF sensor. What I propose to do is to plug the nipple on the air inlet elbow to eliminate the unmetered air. This would only be a temporary deal until saturday when I would have time to remove the waterpump and replace/repair the o-ring seal and then put all the opti vent harness back as normal. I just dont want to chance damaging the optispark by doing this. If it's better to just leave the unmetered air situation alone until saturday then so be it. I will only be putting about 125 miles on the car between now and saturday FWIW.
 

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If you step back a tad you might decide easy to overthink. The vent was added to design to mitigate ozone and humidity -->longterm<--. I'd just disconnect and plug both ports on the intake side. Don't intentionally drive through puddles of course. Not much affect on performance or parts in anything you'll do near-term as long as you can get to the R&R soon.
 

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Discussion Starter #7
If you step back a tad you might decide easy to overthink. The vent was added to design to mitigate ozone and humidity -->longterm<--. I'd just disconnect and plug both ports on the intake side. Don't intentionally drive through puddles of course. Not much affect on performance or parts in anything you'll do near-term as long as you can get to the R&R soon.
That's what I figured but just wanted to ask before making a possible dumb mistake.

Thanks again.
 

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do not remove the vacuum line to opti dist. since you did then , the optical sensor will corrode due to the corrosive gases created by arcing of the rotor . I know all about this because I worked on ac equipment that had relays high powered ones that created arcing in a sealed box .. the circuit board components got damaged severely .. had to do mods to remove this gas .. venting system worked ..

the seal popped out no problem on a vacuum leak since it is regulated by the filter orifice on the vacuum line.. PCM is programmed to act properly because of that vacuum loss .. the major problem is water intrusion into the opti so no car washes or driving in wet roads .

IMO you noise is not that opti seal .. the vac on the opti is too small to make any sound . I would put and I have one a vacuum gauge should be 17-21 inches .. idle .. if it makes a noise at 2000 rpm only that can be another failure not vacuum .. thinking exhaust leak .
 

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Discussion Starter #9
do not remove the vacuum line to opti dist. since you did then , the optical sensor will corrode due to the corrosive gases created by arcing of the rotor . I know all about this because I worked on ac equipment that had relays high powered ones that created arcing in a sealed box .. the circuit board components got damaged severely .. had to do mods to remove this gas .. venting system worked ..

the seal popped out no problem on a vacuum leak since it is regulated by the filter orifice on the vacuum line.. PCM is programmed to act properly because of that vacuum loss .. the major problem is water intrusion into the opti so no car washes or driving in wet roads .

IMO you noise is not that opti seal .. the vac on the opti is too small to make any sound . I would put and I have one a vacuum gauge should be 17-21 inches .. idle .. if it makes a noise at 2000 rpm only that can be another failure not vacuum .. thinking exhaust leak .
I do not need any issues so I just reconnected the vacuum to the opti-spark. I have a new set of cap seals coming from my buddy at MSD.
 
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