yellowlust

Ok, 130k miles and the water pump finally goes. Yeah, I can live with that. The replacement Delco pump is only $100. I don't drive the car very often anymore but I do need it to move under it's own power.

I spend a couple hours draining coolant, pulling hoses and popping off wire connectors. Not too bad, a little messy but I've done worse.



I get the pump loose and have to fight to get it out, not a lot of room to maneuver. It finally comes out and I'm all proud of myself.

But then I notice that I had made a major boo boo.



So instead of a simple water pump swap now I'm staring at an OptiSpark too.

I'm tempted to just superglue the connector back on but with 130k miles I really am on borrowed time with the original OptiSpark.

At this point it may be cheaper to throw an LS in there.

don hall

You have done most of the work to replace the opti, so you might
research optis (SacCity is one to consider).

yellowlust

Great info. Yeah, I need to start shopping for the OptiSpark.

don hall

This link is 'old' info to you, as you have just completed most of it,
but it will help as a reminder during reassembly:

https://www.corvetteforum.com/forums...-pictures.html

yellowlust

I did see that post and that was very helpful. There are some slight differences with the earlier LT-1.

The big question is do I replace the Opti or water pump drive seals? Only if they are leaking?

8a8mfh

The felpro timing cover set has all the seals and gaskets. Its approx $8 - $12 for all made in usa parts at most local parts stores. Its well worth it while you're there. Not too hard to replace.

yellowlust

Even the special teflon seals? I was reading and someone recommended using only GM parts there.

antfarmer2

Did not see where they pulled the knock sensors a must for a proper flush
And I would put the pump back on and clean it up to much crap and not worryed about the opti now

yellowlust

How would you recommend to fix the wiring connector then? I have a feeling I can't leave it loose.

don hall

Without hesitation, replace the pump and opti.

yellowlust

I had contemplated the timing chain but then hear stories that they don't really wear too bad. I did the timing chain on my L98 but it was making a slappy noise.

Maybe the LT-1 chains do better?

don hall

From another forum:

"About the timing chain, failures are not common, many people use high mileage ones for h/c setups. If the Timing chain was stretched (which most old ones are) it wouldnt really matter unless it was jumping time and at that point it would be a bigger problem and wouldnt happen intermitently. I have seen some pretty damn loose ones come out of LT1s that ran great. GM actually set them up pretty loose for ease of assembly. Try and put a good aftermarket one on and youll know what Im talking about."

corvetteronw

Good to see you are still out there! Here are some pics I took at the NCM of an LT4. This might help you visualize where everything is supposed to go.
By the way - I ended up buying a red LT4 vert and owned it for a year then sold it back to the guy I bought it from. Hope things are well with you and your family!

yellowlust

Hey, Ron! Everything fine. As soon as the kids are older I'll be able to let them ride in the Vette.

yellowlust

So just to confirm the engine pulls just pops off with three bolts and no puller is needed?

cardo0

I think u mean the dampner/pulley pops off? I recall u may need a persuasive wack but no puller. Now the hub would but that stays on and dont mess with it as it is timed/located at the factory to put that cast triangle pointing at #1 at TDC. And why change the timing chain unless it has slipped a tooth? Yes they do stretch over time but on a stock car u will never notice the power difference and they are all metal that should last a lifetime unlike early GM cam timing gears. Your asking for a whole lot more work for really no noticeable difference in performance or reliability by changing the timing set now.

Yes just replace the opti. 130k mi on the original is outstanding and u got your monies worth there. I dont know how anyone could repair the electrical connections on that broken connector. That opti is trash now - no question.

After replacing like 4 opti's in my camaro i would only buy the AC Delco opti. Havent tried the Delphi unit but all the repro opti's are not worth the effort and will fail again in short order. Summit racing used to have the best deal on AC Delco opti's FWIW.

Your early opti has a drive shaft that u will need to replace the seal on while installed/inplace. I used a deep socket for this with a little heat from a heat gun (or hair dryer) to stretch it on. The new Felpro gaskets are peculiar and some go on dry. Yes no oil or liquid. Funny but that is contrary to what i learned the hard way with seals but its true. And u have to read the Felpro instructions carefully as not all the seals in the "kit" are installed dry. Read carefully to find out which ones are which.


Good luck and hope this helps.

1 more item i would replace the dampner/pully as the elastomer does dry out and crack up over time from ozone. I used a cheap Pioneer replacement <$50.

yellowlust

Do you recall which four brands of Optis you had?

cardo0

Yes and no. Stay away from Cardone. Ive replaced 4 opti's but dont think they were all different brands. I recall my first replace was a rebuilt Cardone from O'reillys when they were still Kragen - lasted <1yr. Then some repro brand from Rock Auto new but dont think it was Cardone because of last experience and next a new opti the dealer had installed failed also - i dont know if AC delco. Last was AC delco from summit i bought and no problems in like 3-4 years.

higgyburners

ACDelco and you wont have to do it again





Old Opti














New ACDelco Opti

higgyburners

You Might consider doing this waterpump Mod also, its very easy and will save you when the water pump fails you again. When you don't drive these cars often and let them sit the pump seams to crap out more often.