I'm looking at buying a '89-96 C4 & in the course of talking to owners, I've run into 2 who said that they replaced the Optispark together with the water pump..............with the water pump being responsible in fouling up the Optispark because of leaking or moisture or condensation or..........something to do with water. Is there any plausible truth to the above scenario? And if so..........

My extremely stupid Optispark question is:

If the unit is that susceptible to moisture, is it not also susceptible to getting wet in the normal course of everyday driving, puddles, rain, car washes etc? Or is it strategically placed so that the only thing that could get it wet is the water pump? I'm not trying to be funny or stupid here. Just trying to anticipate what type of a pain this could potentially be. Thx. for any help/info you could provide.

 

..... Narrow your search to 89-91 TPI ... no Opti-Spark ... no problem ...................

 

Opti Spark came on 92-96 vettes withthe LT1.

 

95 and 96 opti is vented ,less problems.my original one was over 12 years old and still working but I changed it to avoid problems when I replaced gaskets and water pump

 

My opti lasted to 125k and went out because of autoxing in a river or so it seemed.

 

To answer your origninal question: is it plausible? YES.
All in all the Optispark isn't bad technology, it does have some implementation issues.

They can be suceptable to moisture or water intrustion (especially after the cap seal starts to dry out and crack) that can cause corrosion and eventual issues . So you should never pressure wash your LT1/LT4 engine. (but this is also true for a lot of modern engines)

Mounting it behind the water pump puts it directly underneath the water pump weep hole, so when the water pump starts to go, coolant can leak onto the opti. It's for this reason that most folks replace the water pump and opti together. (well.. and the fact that it's not a small job to get to the opti in the first place,... and you have to remove the water pump anyway...) When you replace the water pump a lot of folks recommend plumbing a small hose from the weep hole past the opti to avoid this potential source of moisture.

Normal every day driving in the rain etc, shouldn't be an issue. Fording small rivers and streams would be. Heavy rains and deep puddles MAY cause an issue, but most of the time, normal driving in the rain isn't a problem. Many folks have had their OEM Optisparks last a long time. I've had 2 C4s (1996 and 1994 LT1s) and replaced the opti once. A big problem today is finding good replacement parts that don't cost a fortune. There are a lot of different opinions on Opti brands etc. Another problem with the opti is that when they start to go, it's not always obvious that it's the opti, the symptoms of a bad opti seem to vary widely.

The LT1 isn't a bad motor, neither is the L98. Personnaly I like the other changes they made to the car that came with the LT1 years, but that's all a matter of opinion.

 

Many times through deep puddles and driving my 95 in the rain, zero issues. If opti worries are all that's stopping your from owning an LT-1, buy one. Unless you do something dumb like pressure wash the damn thing, it won't likely give you any trouble. And if does, replace it. It's just a distributor....

 

The car is made to drive in the rain, you won't have an Issue, if it worries you like said before get a 95-96. The opti is a scheduled replacement part, it is not designed for the life of the car weather you get it wet or not.

Did the L98 owners tell you what a bear it is to replace the water pump, fuel injectors, and intake manifold on an L98? these are a cinch on an LT1, which monster is preferable?

 

How come some vender hasn't tried selling a rubber boot for the optispark?

 

No, narrow your search to a '95-'96
Best of the C4 series.

Don't let the OptiSpark scare you away from a great car.

As with anything else, buy the newest best maintained vehicle you can afford.
Don't buy a beater to save money, and then tell yourself you will fix it up.
99% of the time, that will end up costing you more in the long run.


Purchased mine with just over 45,000 miles and now have just over 120,000 miles, without any issues.
Just normal maintenance, and still on the factory original water pump and Opti.





Well there you go, a nice business opportunity for you.

 

Pressure wash an L98, and it won't run either. The LT1 is a) 25% more powerful, b) more reliable (yes it is, or would you rather change head gaskets)). If changing a water pump and an opti (average service life 160k+ miles) scares you, you shouldn't be buying a 20 year old car.

 

I own a 95', with 60K, no opti issues as of date. Buy the best maintained 95-96 you can afford. If you have opti issues, this site is full of threads with photos on the issue. It is not any thing to be affraid of if you turn your own wrenches. Whe my water pump bearing failed and i had to change the water pump, I took the opti out just for cleaning purposes. The job is not that hard....IMHO.

Good Luck with the Hunt.

 

I had to take my 94 through flood water that almost came up to the wheel centre's last winter, it was the only way home,so I had no choice, absolutely no problems, but I guess with the air dam you can create a "hole" in the water to drive through! when I bought the car I did buy a Chandler Motorsports opti as a standby but thankfully haven't had to use it, but now Im 12 months into owning a C4 I've come to understand that an MSD may have been a better choice..

 

Thanks everyone for your responses, opinions, advice & reassurances. I suppose I just freaked out a bit after hearing 2 owners tell me about the same exact issue back to back. .

 

I replaced an Opti on a '94 LT1 (153K miles) and replaced the Opti on my '96 LT4 (124K miles)...the '94 replaced because the water pump took a dump on it, the '96 because the bearings went out. If you're a decent mechanic or have a friend/bro-in-law that's a decent mechanic you swap both the Opti and water pump in an afternoon...figure longer if you're changing the plug wires too (which I would recommend).

As Boxcar suggested spend the extra bucks to get a nicer car if you can, lots of good deals out there -just note, low-mileage doesn't necessarily mean better.