Hi there everyone. Haven't been on the forum in a real long time. Anyway, I'm a hair away from buying a 45.5k mi '96 LT4 coupe. I spent some time on the forum today and a couple of threads really got me concerned about the reliability of the Opti-Spark. Is this set-up really junk? Are the negative comments I've read the rule or the exception? I'd really like to get some feedback prior to making a 2.5hr plane trip and then spending almost 13hrs to drive back something that I might end up regretting buying. I'd really appreciate any comments about this. Thanks in advance!

 

From my reading, it seems that the later ones (95+ I think, 96 for sure) are vented to allow moisture to escape so they're more reliable. Mine's a 96 with 126,000 miles on what I believe to be the stock optispark and it's running strong. What kills them usually is a water pump leaking down on top of it. With only 45.5k miles I wouldn't let this worry keep you from buying the car if it's in good shape at a reasonable price. Love my LT4, it's a great engine.

 

My original owner 1996 LT4 now has 46k on it. Original OPTI-SPARK still in use, sure hope it lasts a long, long time.

 

Thank you very much for the input. It's just what I read has discouraged me a little at this point. Hopefully, I'll get a few more positive replies such as yours to make me feel a little more comfortable at this point.

 

Thank you as well! A few more positive replies like this and I'll probably make the arrangements to get this car. I just don't understand why so may negative posts regarding this ignition.

 

There is no reason whatsoever that fear of the Optispark distributor should scare anybody away from buying a C4 with the LT1 or LT4 engine. The revised, second-generation Opti, which was used on the '95 and '96 Corvettes, was vastly improved over the first-gen units. All Optis were vented, but the first-gen units were passively-vented, with weep holes along the lower edge of the housing. The second-gen units are actively-vented, with hoses pulling filtered air from the intake bellows through the Opti housing, and into the intake manifold. The second-gen units also had a revised bearing, and revised coupling to the camshaft (which, unfortunately, makes them not a bolt-on replacement for the first-gen units).

The active venting on the second-gen Optis solved the problem with condensation buildup and ozone-caused corrosion within the unit. These units tend to be more reliable, long-term, than the first-gen units were.

Crucial with all of the Optis is to keep them dry. You do NOT want to hose down the engine to clean it up, and beware of coolant leaks from the water pump, or hoses. The placement of the Opti directly beneath the water pump leaves it very vulnerable to coolant baths when the pump fails. Some owners have added a drain hose to the weep hole in the bottom of the pump, to drain away minor seepage from the pump such that it will not find its way onto the Opti.

Many second-gen Optis have gone well beyond 100K miles without any service.

The Opti is a nuisance to replace, because of its location, but it's just a bunch of bolts. Don't fear it. The best C4s were the last ones, and the Opti is no reason to stay away from one of these great cars.

Live well,

SJW

 

my 95 went at 45k. my brothers 95 never had a problem sold it with 81k. i have a 94 now and the original owner changed it at 110k. i have 168k on the clock i guess what i am trying to say is you never know with these things. good luck

 

Just over 125,000 miles on my '96 LT4
Still using the factory original Opti-Spark.
And I wash the engine with soap and water once or twice a year.

So no, they are not "junk".

Some of the aftermarket replacements might be though.
Two of the biggest issues with the Opti are bad quality replacements and/or improper installs.

 

Don't let the opti scare you. It's not all that hard to replace. Every car will give you problems, no matter what.

 

Gents, I want to thank everyone for all the replies. Actually, reading these actually do make me feel more confident in picking up this car. It'll be the first Vette I've owned since I sold my '77 back in '91. Looking forward to rejoining the ranks of the "plastic-fantastic" owners once again.

 

Optispark is fine as long as its an o.e. quality unit..(Or a 92 thru 94, that has been converted to a vented setup is equally reliable).

if you could do some research into 95 thru 96 vntd unit failures, you will likely find one of the following:

1. Vent system malfunctioned, prob the owner didnt even realize it

2. The owner or previous owner (stupidly) thought they were doing themselves a favor by replacing their working fine oe unit with a substandard aftermarket unit to avoid failures down the road.

3. Somebody was doing something stupid with the car. Not noticing a leaky waterpump . Or pressure washing the front of the motor on a regular basis.

4. Extreme mileage beyond 150k. Note the cap/rotor will wear out just like conventional distributors. You can buy a replacement cap/rotor. Dont dare throw away that good quality oe base unit.

these cars run real hot stock (220 f) and that shrinks/embrittles the optisparks seals allowing water intrusion.

I modified my fans and tstat. 174f is a typical operating temp For me.

If you must replace the gen 2 (95 thru 96) optisaprk , i suggest the delphi unit.

Dont do any remanufactured in china distributor. note the ac delco, from the dealer, are remanufactured in china

 

I was running the original on my 1995 LT1 up until about 80,000 miles. I caught my water pump leaking, so when I replaced that, I ended up putting a new cap and rotor on my opti-spark and it's been going strong for nearly 9,000 miles and counting.
Like previous replies have mentioned, the 95/96 opti-sparks are much more advanced. When my water pump began leaking, my car became a little harder to start, but that was because the rotor was becoming corroded. The sensor in the opti was still going strong, which is why I only changed the cap and rotor.

I'd say go for it if that's the only thing holding you back. I am a 20 year old college student that is a rookie when it comes to mechanic work. So, even if you need to replace even just the cap and rotor, it's not something to be worried about.

 

I concur. It should easily last as long as the water pump and if that is being replaced it is the next thing to come off the front of the motor, so replace them together and be happy forever.

 

I have a 1992 Coupe with 108,000 miles. The car has the original Optispark still in the car, it runs great! (and yes, I drive in the rain) A 96 with 45k will be fine.

 

Damn, you're lucky. On my first 93, the opti died right at 80k miles.

 

One thing I would not do is wash the engine while hot. A cold engine is fine, but a hot engine will cause steam and in my experience that steam can get in the Opti and cause it to fail. I have 93s so maybe the later vented optis don't suffer from the steam problem.

 

One thing we haven't talked about is the accuracy of the opti-spark. One of the most accurate.

 

Or perhaps you were just unlucky?
There are more Opti's out there that didn't fail than there are that did fail.



That is the reason they went that route.