compyelc4
Well-known member
- Joined
- May 1, 2002
- Messages
- 609
- Location
- Dayton, Ohio
- Corvette
- '95 LT1 Coupe, Comp Yell; C6 Roadster, Vel Yell
This is for those of you who are acquainted with Opti's or have read a fine Opti disassembly article archived on this site (Mike Chaney's Optispark Disection Page). I welcome constructive comments and suggestions. Please offer me help if you can. I love my C4 but I can no longer afford $450 Opti annually. This would be an excellent reason to get a C5............but I don't WANT a C5. I want a reliable yaller C4!!!!!!!!!!!!!
Here is my story. I am replacing my '95 water pump at 20K! Inner seal failed, bearings compromised with antifreeze, leading to outer seal failure. I caught this very early. There were no telltale signs of antifreeze on the Opti. A previous post on this site started me thinking about my Opti-Spark which was replaced last summer and now has 5K on it. The pump is off at the moment and is waiting for me to install the new pump.
I pulled the 4-pin harness on the newly replaced Opti, peered down into the receptacle and behold the pins are sulfated blue just like my old Opti-Spark at 15k.
I know there has been no water intrusion into the receptable because GM sealed that up real good when the Opti was replaced and I have made sure that the engine compartment has stayed dry as a bone since then. Sure enough, the channel was clean as a pin. So how did the receptacle pins sulfate. Eureka! Those pins must be exposed to the inside of the Opti somehow! For grins, I grabbed my old Opti-Spark and blew down through the receptacle channel. Sure enough it was not a sealed channel.
I opened up the old Opti (which is vented). What a freaking mess. The "distributor cap" of the Opti has 8 pins just like the inside of a standard GM distributor cap. Also there is that familiar-looking rotor too. Each pin, and the brass tip of the rotor are so badly sufated (pins are thick with white sulfate and the rotor tip is blue with sulfate) that I am amazed that I got any spark at all. I can see no sign of water intrusion but there is this this anomoly: There are a few very tiny (head of a pin size) beads of what appears to be turquoise blue goop. I did the old micro-taste test to see if it could be caused by anti-freeze. It was NOT. It was acidic! Burned my tonque a bit. How the heck did that acid form? I used a strong magnifying glass and light to look very carefully at the areas around the neoprene seals. The seals are applied circumferentially around two of the three "pancake-looking" parts of the Opti unit so that the system is COMPLETELY sealed to the outside EXCEPT through the forced vent system. There is absolutely not one sign that any liquid compromised those seals FROM THE OUTSIDE! For the record the external 4-wire receptacle channel opens into that part of the Opti that contains the optical pickup and sending unit (that is the heart of the system). Actually, the receptacle pins protrude directly from the pickup! Simply, the pickup sends and receives pulse signals to and from the CPU to help control engine timing. For some reason though, that enclosure had absolutely no sign of condensation, even though it is open to the other portions of the Opti that did have evidence of acidic condensation. So why were the pins that are exposed to the same internal air sulfated while nothing else was? How the heck can I stop it?
Regarding the Miracle Vent, it is my theory that GM recognized a problem with the pre-92 (I think) Opti. I understand they have a free replacement program on those now. GM figures that the water pump or washing engines down with a hose caused water to enter the Opti, or maybe condense in some magical way (the thing is sealed like H_LL folks!). They surmize that, hey, lets get rid of the water vapor by sucking air out from engine vacuum and drawing air in from downwind of the air cleaner . This recirculating air will certainly keep the inside of the Opti dry. Wrong. Wrong. At least, in my opti, the venting does NOTHING. Somehow condensation is still occuring at a rate greater than the vent system's ability to draw it out. Also, somehow, the electric arcing between the rotor and pins creates an atmosphere (ozone?) which turns the MARTIAN condensation to acid thereby rendering all the metal contacts as effective as if they were barnacles.
I am very ****ed at GM right now. There must be some way to prove to those engineers that they HAVE NOT SOLVED THE PROBLEM! SO DO THE RIGHT THING. My pristine C4 is about 6 water pump bolts away from being sold traded for a C5.
Can anyone tell me how to keep that acid crap out of the Opti so that it does not corrode itself to death every 5,000 to 15,000 miles). I'm going to open up the new Opti tomorrow. I am expecting to find the same acidic crap starting to build up.
Thank you for taking the time to read my VENT!
Here is my story. I am replacing my '95 water pump at 20K! Inner seal failed, bearings compromised with antifreeze, leading to outer seal failure. I caught this very early. There were no telltale signs of antifreeze on the Opti. A previous post on this site started me thinking about my Opti-Spark which was replaced last summer and now has 5K on it. The pump is off at the moment and is waiting for me to install the new pump.
I pulled the 4-pin harness on the newly replaced Opti, peered down into the receptacle and behold the pins are sulfated blue just like my old Opti-Spark at 15k.
I know there has been no water intrusion into the receptable because GM sealed that up real good when the Opti was replaced and I have made sure that the engine compartment has stayed dry as a bone since then. Sure enough, the channel was clean as a pin. So how did the receptacle pins sulfate. Eureka! Those pins must be exposed to the inside of the Opti somehow! For grins, I grabbed my old Opti-Spark and blew down through the receptacle channel. Sure enough it was not a sealed channel.I opened up the old Opti (which is vented). What a freaking mess. The "distributor cap" of the Opti has 8 pins just like the inside of a standard GM distributor cap. Also there is that familiar-looking rotor too. Each pin, and the brass tip of the rotor are so badly sufated (pins are thick with white sulfate and the rotor tip is blue with sulfate) that I am amazed that I got any spark at all. I can see no sign of water intrusion but there is this this anomoly: There are a few very tiny (head of a pin size) beads of what appears to be turquoise blue goop. I did the old micro-taste test to see if it could be caused by anti-freeze. It was NOT. It was acidic! Burned my tonque a bit. How the heck did that acid form? I used a strong magnifying glass and light to look very carefully at the areas around the neoprene seals. The seals are applied circumferentially around two of the three "pancake-looking" parts of the Opti unit so that the system is COMPLETELY sealed to the outside EXCEPT through the forced vent system. There is absolutely not one sign that any liquid compromised those seals FROM THE OUTSIDE! For the record the external 4-wire receptacle channel opens into that part of the Opti that contains the optical pickup and sending unit (that is the heart of the system). Actually, the receptacle pins protrude directly from the pickup! Simply, the pickup sends and receives pulse signals to and from the CPU to help control engine timing. For some reason though, that enclosure had absolutely no sign of condensation, even though it is open to the other portions of the Opti that did have evidence of acidic condensation. So why were the pins that are exposed to the same internal air sulfated while nothing else was? How the heck can I stop it?
Regarding the Miracle Vent, it is my theory that GM recognized a problem with the pre-92 (I think) Opti. I understand they have a free replacement program on those now. GM figures that the water pump or washing engines down with a hose caused water to enter the Opti, or maybe condense in some magical way (the thing is sealed like H_LL folks!). They surmize that, hey, lets get rid of the water vapor by sucking air out from engine vacuum and drawing air in from downwind of the air cleaner . This recirculating air will certainly keep the inside of the Opti dry. Wrong. Wrong. At least, in my opti, the venting does NOTHING. Somehow condensation is still occuring at a rate greater than the vent system's ability to draw it out. Also, somehow, the electric arcing between the rotor and pins creates an atmosphere (ozone?) which turns the MARTIAN condensation to acid thereby rendering all the metal contacts as effective as if they were barnacles.
I am very ****ed at GM right now. There must be some way to prove to those engineers that they HAVE NOT SOLVED THE PROBLEM! SO DO THE RIGHT THING. My pristine C4 is about 6 water pump bolts away from being sold traded for a C5.
Can anyone tell me how to keep that acid crap out of the Opti so that it does not corrode itself to death every 5,000 to 15,000 miles). I'm going to open up the new Opti tomorrow. I am expecting to find the same acidic crap starting to build up.
Thank you for taking the time to read my VENT!
