This poll is only for C4 owners whose Optispark has ever failed (whether once or multiple times).

I'm trying to search for patterns.

This is my first poll ever, so I hope I get it right . . .

Jim G

 

By 20k miles I was on my third opti. At that time I upgraded to a GenII vented opti. Have been good for the last 11k miles.

 

Soooooooo.......other cars with the LT1 have other, unique factors causing opti failures?

KW

 

on my 96, by 125,000 my Opti had gotten one new cap and rotor four years earlier; it failed because (1) I deliberately power washed it to see if it was as sensitive to water as everyone said it was, and (2) a few weeks later, I drove it in driving rain and yes, it finally died BUT if my vacumn / vent harness both to and from the Opti hadn't (a) been cut by the serpentine belt and (b) rotted through from oil and heat, it would have probably still ran. When I did disassemble it, everything inside was green from moisture and corrosion, but up until then the engine still ran and ran well. two well deserved for the often maligned Opti

 

My 92 had a non-vented, one time it was 29°F in Camp Pendleton, CA, and it took few seconds for it to start.

It had 195K miles.

My 95, and 96 with the MSD never had an issue.

Now few years ago before the MSD, I bought the DynaCrap for my 95, and that a total piece of Ghit.

 

My latest Opti failed because I unknowingly broke off the vent hose near where all the dirt is

I can tell it's going be hard to tell the difference between measuring trends in Opti failure vs. simply measuring trends in what the typical vette owner is like... perhaps having an extra control group having the same choices would be better!

 

I stupidly did not think of two obvious questions to ask:

1. Do you sometimes wash the under hood area of your C4?

2. Do you use automatic car washes (some of which have chassis sprays)?

I don't know how to modify the poll though. There don't seem to be any edit controls available.

So, IF you would be willing to, post here whther or not you use car washes and whether or not you wash or clean with liquids under the hood!

Note the emerging peaks for "hotter climates" and the older of the 2 Opti configurations.

Jim G

 

when I first got my car, yes I aggressively cleaned the engine areas with detergents, garden hoses, pressure washers and car wash wands set on high.

what my subsequent experience showed me was that:

(one) the late model Opti with its vent harness is extremely resistent to water;

(two) with that said, the vent harness, both to and from the opti should be inspected for cuts, oil softening, rot, or any other failure;

as to Opti's in general, the cap is sealed to the body with a o ring; like all o rings, it deteriorates over time; an Opti, like ANY distributor, should have it's cap and rotor replaced on an occassional basis. Resealing the new cap with a small bead if silicon has gotta help here also.

In my opinion, the most overlooked failure mode, if you wash an engine, isn't necessarily internal to the Opti, but rather where the low voltage wiring harness plugs into the Opti; this connection is almost completely vertical and was seemingly designed to trap water. Mine was wet and green from corrosion; the bad news is that the electrical connectors themselves on the Opti end are thin and recessed, and difficult to clean. The good news is that replacing the Opti cures one half the problem, and the low voltage harness, which is only a foot or so in length is generally available for twenty or so dollars (sometimes less).

If you do have a damaged vacumn line harness, there is nothing sacred about the factory harness; it can be easily replaced with bulk vacumn and/or more robust small fuel line hose and then installed in a more protected route.

Now, generally gone are the days I clean engines or electrical components with water, although I certainly clean other parts, (suspensions, brakes, chassis, etc.) with a power washer. I now use (lots) of brake cleaner and (lots) of paper towels around the motor or anything electrical.

 

Quote:

Originally Posted by Kevin Woods

Soooooooo.......other cars with the LT1 have other, unique factors causing opti failures?

KW

Don't know about failures, but just the opposite. I know a mechanic who worked for a police dept. and told me about well over 100,000 miles and no problems on lots of optis, but not in vettes.
BTW I did not vote!! I have never had a opti failure. Start a D44 failure and Im all over it!!

 

That's what intrigues me. Lots of poilce cars and taxicabs used these, and the track record there was very good - regardless of climate.

So, what's different about police and taxicab service? Some things I can think of quickly:

- Polcie & taxicabs frequently run almost 24 hours per day (s0 they are always HOT under the hood - no chance for condensation, and water spashed into the underhood area probably evaporates off into steam almost right away

- They put on their incredibly high mileage in a very few years, rather than the slow mileage accumulation on a typical Corvette, so "years of exposure" doesn't really apply (unlike our 20 year old C4s)

- I'll bet they NEVER get cleaned under the hood

- I'll bet they seldom get washed externally, but when they do, I'm sure it's NOT careful and slow but rather quick and using a sprayer rig

- They probably seldom see high engine rpm service

- There is probably a higher tolerance for inferior performance (what taxicab driver of police officer cares THAT much about his on-the-job ride?)

There HAS to be a pattern here somewhere . . .

Jim G

 

I have had two LT1 Corvettes, a 94 Z07 coupe and my current 93 Roadster. Neither have ever suffered an opti failure.

My F Bodies have suffered 3 cumulative failures. All mine have been on unvented optis after I washed a hot engine. Cold engine was no problem after washing as the opening in the unvented optis is pointed down. But if you create steam by washing a hot motor you will kill your opti.

I find them pretty robust excepting the washing issue.

Perry

 

My '96 Impala SS has 247K miles on it. The Opti has never been messed with. It's had plenty of high RPM service. Never been cleaned under the hood. Lots of "Laser Wash" car washes. I have no tolerance for inferior performance.

It may have something to do with being higher off the ground. It may have something to do with the Impala being a 96 vs my vette being a 94.

My 2 cents worth.

 

The 96 Opti is the improved version, while the '94 is the older one.

The Opti being higher off the ground in the Impala might be vERY significant - less road spray and less dirt as you go higher.

I wonder if some sort of sheet metal "shield" in front of the Opti area would help?

Jim G

 

BTT

Jim G