I have a 1992 Corvette that was just diagnosed with a faulty/leaking water
pump. I called the dealership and was given a price of approximately $650
for the job. Then I was told that the optispark module needed to be replaced
since the water pump typically leaks on the unit and as a result, once the
pump is repaired, the car will not run. This doesn't sound right to me, but
I'm not very hands-on when it comes to my motor compartment.
Can anyone tell me if this is true?
Thanks in advance,
My '93 was running like absolute crap because the optispark was of the
unvented variety and over years it had gotten all full of rust in there, so
the cylinders were firing essentially at random. I don't know if that came
from a slow leak in the water pump or from the fact the original owner lived
in California near the coast and humidity just got to it. Anyway, the opti
isn't cheap. After you remove the water pump it is not a big deal to check
it out. If it's clean and rust-free, it's fine. If the water pump has been
leaking onto it, it might not be. If you do replace it, try
gmpartsdirect.com to save some money.
'93 Ruby coupe, 6 sp (both tops)
Its true. I have a 1992. 1992 was the first year the optispark made its
appearance. Optispark was a great idea but the location of it was
downright stupid. The original optispark did not fair well when it got
wet. The stupid thing GM did was place the waterpump right over the
optispark. When the waterpump or optispark fail people usually change
both. Might cost you 1200-1500 to replace both. I think 1995 the
Optispark was replaced.
No my 95 Had an Optispark ..and so did the 96's....
BUT in the 6-7 yaers I owned it tit never gave me any trouble....
Optispark units can be had for about 300 bucks now... far cry from the
original prices...No idea of what water pumps are going for been a
long long time since I had to replace one on any of my cars (crossed
The reason to replace both is just to save time.. (and labor charges)
since the water pump etc has to come off to replace the optispark...
BUT IF nothing is wroing with the optispark whay sopend 300 or so
bucks to replace it... BUT IF YOU DO replace it with a 94 or up
unit, that has vents for mositure ..
Water pump AC Delco part number 252690, OE# 12509653 (#88926204)
I see that AC Delco has stopped building the unit for $417 and now
sell it in parts. A1 Cardone has a rebuild unit for $185.79 with a $50
core charge. It has been a while since I was into one of these so
correct me, as I know you will, if I'm wrong. All of them were vented,
that's how they got moisture in them, so you need to vent into a
vacuum to keep out the moisture as they started doing in '95.
If they pour coolant all over the distributor while changing the water
pump then it most certainly could be damaged, but if it runs now it
should run when they're done with it. On the other hand, if the
Optispark is near the end of it's life then the water pump will have to
come off again to replace it when it fails.
$650 just for the water pump is a very steep price (that would pay for
the parts, a shop manual, and a very nice set of tools).
If/when you have the Optispark replaced, a new model cap will fit the
old model distributor. The new model cap comes with a vent tube. The
old model distributor can be modified to accept a vent tube. One hose
to vacuum and one hose to dry filtered air will prevent future
problems. No flat-rate mechanic will do this - they just don't have
I just did this repair to my 94. Check out CSKAuto.com they had the pump
and the dist. at the lowest price. Buy an MSD cap and rotor kit as it
comes with the vent tubes and everything, much cheaper than the stock one
too. I bought mine at jegs for 157. The repair is easy. Six bolt on the
pump and 3 on the dist. Be careful though with the drive pin for the dist.
The book says it only goes in one way but I found out it can go in wrong
very easily. Also 94 1/2 and up to 96 have different drives so you cant
use them unless you switch timing cover and drives $$$$$$. Good luck.
The water pump can be changed without making a mess. If they can't
accomplish that, look elsewhere for service. Yes, the water pump is right
above the opti, but one does not lead to the other.
Now, was the $650 for optispark and water pump? If so, good price. If just
for the water pump, rip-off.
All that being said...
If it were me, I'd change the optispark at the same time. Assuming high
mileage (100K+ miles)
If you are not hands on with this stuff, do not try it on your own. When you
get down to all the disassembly necessary, removing harmonic balancer, etc,
it can be a bit much. When my optispark quit on my 92 I had teh luxiory of
having three cars, so I collected parts at best prices and attacked it all
over the time of a week, off and on. Total time all strung together, not
counting the hour searching for the 1/2" socket that had rolled behind
something, etc, this was a 8 hour job.
But don't let them tell you that you have to chenge the optispark. but it is
a good idea.
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