So you're driving an LT1 ey? Noble cause given the Achilles heal nearly every LT1 owner will deal with at one point in their car's life, the OPTISPARK! Designed as an UPGRADE to the type of ignition systems which GM became famous for, the general made a couple of large engineering blunders which cemented this part in the automotive part history books (if they existed ).

Here are the main issues with the unit.

* Sensor failure due to introduction of moisture\condensation (waterpump usually)
* Sensor failure due to heat\RPMS
* Failure of the rotor (resulting usually in cap\rotor explosion)
* Failure of the screws holding the rotor (resulting in the same)
* Failure of the cap due to heat


So what can you do to keep your unit in good shape? The short answer is

PROPER MAINTENANCE

The longer answer is

PROPER MAINTENANCE w/ a bit of luck

Expecting any distributor, even the tried and true HEI design to last 200K miles is asking a bit much. Once you factor in hundreds and hundreds and hundreds of thousands of rotations, calculations, the placement of the part in the engine etc etc Its not realistic to expect the part to last forever. However, its not uncommon for them to fail in short order. Its also not unusual for them to past 100,000 as well.

So what is the difference between a 100K optispark, and one with a shorter failure interval? Well, usually a couple things. Here's what you can do to keep your unit running good and extend the life of your optispark.

* Depending on your driving habits, replace the cap and rotor every 30-60K miles. Shorter realistically given the cheap price of a replacement.
* When you replace your optispark, replace the waterpump WITH it. Don't cheap out on it, because if you do, you risk leaking into your unit and it failing.
* Make sure your engine is properly cooled, high under-hood temperature will encourage failures.
* Avoid driving through large puddles or in large rainstorms.
* If you are getting your car detailed, make sure you tell them your car's weak spot and warn them against an under-hood power wash.
* If you notice your water pump failing, replace it IMMEDIATELY.

Added by members
*"Beware of going threw power car washes with the air dryer as you leave, I was in a hurry one day and decided to go threw one. The air shoved water into my 100k mile opti and thats "the end of the story"" -DJJAB57


Ultimately, even the best maintained car will see a failure given a long enough period of time, but these simple steps can extend its life and keep your unit running strong.

Also, consider throwing salt over your shoulder and avoid stepping in cracks.

 

Excellent post. All great suggestions to keep the Opti working. It seems that the water pump is the weak link however. From reading the posts, the higher mileage LT1's have less opti issues. Many have original opti and water pump up to 100K miles.

 

If I was to replace my OPTI and went with one other than A/C delco.This does make me think would I buy yours>>>Maybe.I just had mine off my car cleaned everything upput it back on and hope to go a few more years.I never did open it up because of these screws that I did n ot have any kind of wrench to fit it.I now have a wp drain from my weep hole.I hope mine goes to 100 K without any problems

 

Nice Thread. What all do you have to remove to replace cap/rotor? I'm at 53k miles, looks like previous owner replaced WP 10 years ago w/25k miles on it.

 

I would never just replace the cap and rotor. If Im in there Im definitely changing the whole unit and I would suggest if you dont have the vented style seal it with some rtv sealant all around and make provisions for the weep hole with a elbow and some hose. Just my 2 cents lol

 

Here is a link on how to upgrade your opti to a vented system. I just did mine.

http://www.corvettefever.com/howto/16758/index.html

Here is the part # for a GM vacuum hose kit.
12555323 The part # given in the how to is an old #.
I pulled the P/S pulley to run the hose kit up to the intake away from the belt.

One thing the article doesn't show that I did was to remove the P/S pump pulley to better route my hoses away from the belt and to get access to one of the water pump bolts with the hose in place.

 

Does GM still make Optisparks? Several vendors on Ebay claim they're all outsourced to overseas manufacturers now, none of which are affiliated with GM. Does anyone know if this is true or ?

 

Cool post, but I disagree with all of the hype that the optispark is a flawed designed! I have yet to have problems on my daily driver 96 and I have driven in noreasters, blizzards, tropical storms, and the like. I think it was a good idea for more accurate timing, and honestly, from my experience, its as reliable of a part as the rest of the car. People make the optispark sound like its gonna fail, but thats not the case! I know it may be delicate if its saturated, but like I said, I have had no problems even in bad storms with lots of rain!

Just figured I would throw that out there

 

Yeah I hear you. But not everyone wants to drop between $100-400 every 30K on their distributor. If your just maintaining the unit, its not a bad idea. For $28 from us, you can't beat it with a stick for just keeping it running.

Delphi from what I understand switched from MIM to MIC, but I can't confirm. I have no idea where Delco is making theirs, but they are still using the Mitsubishi sensor, so that still makes it the best unit out there.

Most of the people selling optisparks on eBay are just copying our listings. We haven't updated the "delco doesn't sell these anymore" part because they stopped and started again, however we don't want to lose the "Momentum" in the listing since some of them have 2-300 sales on the listing.

However, other sellers just copy our listings because we're the number one seller of aftermarket optisparks. Some of them just copy it word for word

I'm really ramping up my sourcing efforts to try and find the origin factory for the Delco part since they won't sell direct. I would love to sell the Delco "white boxed" for $200

I partially agree with you. The concept is not a bad one, but they ignored people's tendency to run their cars into the ground. I would say the waterpump failure is probably the top reason for the stock unit to fail. And really, that's a simple engineering mistake.

There is someone that has engineered a cheap solution on LS1 tech that I'm hoping will draw out what he did, but it sounds like he's gotten a lot of extra mileage out of his units since doing it.

I couldn't completely visualize what he was saying, but it sounds like he was drilling out an area on the water pump as a backup if the unit failed, it would be the path of least resistance draining away instead of out of the unit onto the optispark. I'll keep everyone updated on that.

In the mean time, make sure you only drive on odd numbered days of the month

 

You drill and tap pipe thread into the hole then run a short piece of small diameter line from the weep hole and route it down and around the opti. This way if the pump fails, it pukes coolant onto the ground, not the opti.

 

46,000 miles on the original opti. Three opti's from 46,000 to 55,000 miles with the 396 and major mods. No more opti changes after 55,000 miles with the Delteq ignition. Its a crap shoot with the opti. It does seem like the heavily modded cars have more problems.

 

Can you draw a picture of this? I wonder if it would be worthwhile to have some waterpumps made this way and sell them.

 

There is a small hole on the bottom of the pump that starts to leak coolant if the bearing in the pump fails. It is directly above the opti. You are just making sure that a failed pump doesn't take your opti out next. It's not easy to get to but you can feel the hole on the bottom even with the pump on the car. You can even put a plastic fitting into the hole while on the car with some sort of epoxy.

 

Frankly it's a little hard for me to believe that an opti can not be waterproofed with ATV sealant around the perimeter and maybe around the plug wire boots. I would also use dielectric grease on the plug wire internal connections for further waterproofing.

If ATV silicone can hold in (or out) hot oil under pressure it ought to be able to resist a trickle of coolant from the W/P.

Can somebody 'splain me why ATV won't solve this (apparently) common problem?

 

I "had" a 93 w/LT1. Had many problems with opti as well as hyd. clutch.
I sold the car and bought an 89 TPI a/t and problem solved.

 

People do this all the time to try and seal up an opti. I've seen opti's powerwashed to no ill effects. I wouldn't do it personally, just like I wouldn't let coolant trickle onto the opti if it can be avoided. Also, sealing the opti doesn't guarantee long life. Moisture is not the only source of an opti failure.

 

not to thread hijack, but we all should be figuring out how to make our LTx cars compete and beat the latest LSx motors.

Im tired of reading threads, in the c4 section, of 'how do I change my spark plugs'

If you go to the C5 section, you will instead see posts of 'how do I shut down liter streetbikes'.

As for the optispark, seal it up w/ RTV silicone, dont buy the MSD-replacement optispark, add a vent cap & system (if 92, 93, 94), new non-MSD wires, and dont worry about it....

Worry about shutting down the newer model corvettes. They are your biggest threats on the road.

 

Don't know much about C5s, but as a long-time motorcyclist I can tell them how to beat a literbike -- find a highway with a speed limit of 185 mph, since at very high speeds the bike's tragically inefficient aerodynamics will overwhelm its power-to-weight advantage over the car. In the real world where most of us live, however, a crotch rocket's acceleration will leave ANY car for dead. In '08 Cycle World magazine published these figures from a test of a stock Suzuki GSXR-1000:
0-60 in 2.78 sec
0-100 in 5.08
100 - 150 in 4.98
150 - 180 in 13.43
1/4 mile in 9.98 sec @ 149.49
Top Speed: 185.29

And remember that the hardest part of a street motorcycle's launch is keeping the front wheel from heading skywards (unlike a drag bike which has a wheelie bar), so throttle modulation is essential. Look at those times and you can see what the bike's 60-100 roll-on time would be. That would be the bike's sweet spot, and why finding an excuse to use it (i.e., passing trucks) is so much fun.

For cheap thrills you can't beat a motorcycle. I'll bet you can find an '08 Gixxer for $7 large or less, and you too will snicker every time you hear the phrase "fast car."

 

I`m new to the forum, so you`ll excuse me if I say something dumb, or obvious to the rest of you. I just read a wonderful thread posted by LT1*C4 about r&r of the optispark unit. I bought what appeared to be, a really super clean 1995 coupe last weekend. Its a one owner, with 78K original miles, ( he had the carfax print out which confirmed the mileage)it is a six speed car, and has a ProCharger super charger on it. I know that the super charger can be a positive , or a negative based on how the car was driven given the extra power now available. Anyway, I drove the car to work everyday all week no problems. Friday, however, it started raining here in northern California where I live. I drive approx. 45 miles each way to work everyday. When I left Friday morning the car was running fine. By the time I got to work, it was misfiring just slightly. I tried to sluff it off to other things, but in the back of my mind I`m thinking Optispark. Coming home Friday after work it was raining harder than in the morning. About five miles from work it started to act up, misfiring, then all of a sudden the power would return. Then really running rough, then smoothing out somewhat again. By the time I got home, I was putting the car in neutral and hitting the brakes a gas together to keep the car running from dying stop signs. This morning, I got in the car to see how it would act after sitting all night. If it is the opti, I thought that it might have dried out somewhat from the engine heat . I started it, and it seems to be OK. Its still raining today, so I`m afraid to drive it anywhere as I don`t want to get stuck. Does this sound like the good ol` opti?

 

my 96 opti has proven very reliable, I think the original would have gone on, limited by the condition of the cap and rotor of course, for almost forever had the vacumn vent harness not failed; the small hose from the rubber intake coupler was cut by the serpentine belt and the larger hose from the opti to the intake manifold was completely rotted through from heat and being oil soaked.

with the cap sealed with rtv and the vacumn vent system intact and working properly, I would not be concerned driving it in any weather that I would otherwise consider safe to drive in. Of course there's a point when driving any car makes no sense; you just reach that point a little sooner in a vette.

of course, GM could have kept the distributor on top of the engine where its accessible. but they didn't.