I have 49,000 miles and Im doing a head/cam package, should I replace the opti? I have no issues,its a 1996, and I see that 25% of people have problems with the MSD units. I will probly stay with a new ac delco if I have too. But the saying " If it aint broke don't fix it" Im not a cheap skate but I see little justification to replace it besides its B*$^% to replace when it goes out.
How many hours and cussing does it take to change one when car is fully assembled?

 

If it is working fine, I wouldn't replace. Once you tear the car down for the cam swap it will be leasons learned. The next time will be a piece of cake. My friends 1995 TA has 155k on the original Gen II opti.

 

In all honesty, it takes me about 5 hours. But I move slow and clean stuff up along the way. I usually spend about an hour of that time cleaning off the old WP gasket material. Not that hard to do, you just have to remove a bunch of stuff to get at the Opti. I always change the Opti seal. I change the WP seal only if it appears to be leaking. If you only have 49K miles and no drivability issues, I wouldn't mess with it. The '96 has the vented GenII Opti which should last 100K miles or so.

If I was in a time crunch, I could probably do an Opti from start to finish in 3 hours.

 

I agree with the "If it ain't broke, don't fix it".

You hear all the time people getting 80k + miles on an original Opti. But then go through 2 or 3 Opti's over the next few years.

Why is that? Is it an improper install? Cheap parts? Or a combination of both?
Something to think about anyway.

I have close to 92k on my car, with the original opti still going just fine. The engine still looks new, with no leaks of any kind.
Hope to keep it that way for a few more years at least.

 

Also, since you are doing a head/cam swap, your Opti will have to come off so this will allow you to open up your Opti and inspect the inside for any oil or coolant intrusion. The 4 inverse torx bolts that hold the Opti together have probably loosened a little over the years, so this is a good time to snug'em down. Also check/tighten the 2 small torx bolts that hold the rotor on.

Here is a pic from a GenII Opti I pulled on my previous '95. This Opti had about 60K miles on it, and I suspect the oil got inside due to leaky seal. This Opti was still running fine at the time I removed it. Luckily, the oil had not gotten on the timing wheel. :



And here is a pic of GenI Opti I replaced on my '94. This is the non-vented style, and you can see some pretty severe corrosion. Yhis Opti had 59K miles on it :

 

It does seem like modified cars have more problems with the opti especially with high RPM driving. My opti rotor screws kept coming loose with the vibration. I finally put in a new GM opti and put loctite on the screws. The new Deltag ignition seem to help at the high RPM's also. Have not replaced the opti in the last three years of drag racing.

 

The reasons to NOT do it now are:

1. yours has low mileage (they usually go out anywhere after 80k-100k for varying reasons).
2. yours is the GEN II OPTI, better seal, vented, and bigger bearing, so failure early is less likely than pre 95 OPTIs.
2. usual failure of OPTIs is caused by contamination from water-pump, but since you'll be removing the water-pump for your head swap, and given the age of the water pump seal (regardless of mileage, rubber has a max life, like tires now suggested at 10 yrs). SO, IF YOU REPLACE THE WATER PUMP while you have it off anyway, it will eliminate this as a possible failure point of the OPTI, while saving some labor time (no cleaning of gasket surface) and only mild cost.


The reasons to DO it now are:
1. the OPTI is still a DISTRIBUTOR, so spark must jump across the air gap, corroding both the rotor and cap contacts. 50K is still alot of mileage on a Distributor cap and rotor.

So, perhaps a good compromise would be to ONLY do the cap and rotor -- albeit a bit expensive, assuming no contamination of the optical sensor, and replacment of the water pump to prevent any future contamination, it should eliminate the possible replacement requirement at 80-100k, not to mention assuring your new heads and plugs get optimum spark.

Also, consider changing the seals (water pump and distributor) in the timing chain cover -- again, rubber has a max life.

 

Excellent advice from the Admiral !!

If the back of your WP looks anything like the following, replace it. You can easily see the stains from leakage along with the beginnings of bearing failure. This WP had 59K miles on it(it goes along with the pic of the Opti I posted above) :

 

Wow Nice advice and no bashing LoL
I will inspect and do new seals. And maybe locktight the screws too. I had my water pump leak over a year ago but I got to it and fixed it in a day. ( I went thru a car wash) I've had no issues at all after that event. I put a rag underneath the WP so it wouldnt drip into the opti.

 

Great photos and explanations......I just bought a '94 with 61,000 and am ready/studying EVERYTHING I can in preparation. I expect it to be delivered by next weekend. Anyway, I printed out your photos and am filing them with the rest of my collection. Thanks for taking the time and energy to put this on the forum.

kc

 

My pleasure.....You will love your '94 !!