Well the Optispark is getting replaced on my 96 LT4 at 80K, it has all the signs, even though the prior owner replaced the water pump at 40K I am going to replace it again at 80K, plug wires as well. So if any one has any tips for me before I dive into this project no amount of input or comments are going unread. I am not sure the best place to order the opti, wires and pump, but I am pretty good at research. Wish me luck, I am not looking forward to pulling the damper. So away we go.... I NEVER THOUGHT I WOULD GET SO MANY GOOD RESPONCES. THANK YOU!!!!!EVER ONE OF YOU HAS HAD SOMETHING TO SHARE THAT I CAN USE.

 

Call Dallas at Vandevere Oldsmobile, he has the best price on the opti's.

 

The damper was the only major holdup I experienced.

Have a small two-arm puller on hand for it. You can probably borrow one from the chain stores, but it is also probably only about $10-15 to buy one.

For GM parts either ac-direct.com or Superior Chevy (search for contact info) are good options.

Definitely replace the WP while in there.

 

Spray the damper with PB blaster and let it soak for a night. I pryed mine off with a big Snap On prybar using the old opti-spark for leverage.
I soaked it for a day first though and it almost fell off. You can get underneath the car and smack the balancer from behind with a block of wood or a big screwdriver/prybar. Do not lose the coupler that drives the waterpump. It has a groove around it and the groove side goes to the block. If you have to get underneath it and want to smack the balancer with a block of wood you'll have to disconnect the power steering lines on the rack. It's not that bad just time consuming. The balancer is the only potential p.i.t.a. with the opti replacement. The spark plugs are much worse and the wires aren't much better.

 

There's a whole thread by SJW on wp/opti replacement. Search for it; it'll help!!! And at 80K, as long as you're in there, I've read you may as well do plugs, too. Maybe belts and hoses...not trying to make this an "engine rebuild", but you know it's not going to be easy getting in there again.

 

When my OptiSpark went bad a few years ago, I thought I'd go nuts trying to get the balancer off. I finally figured out how to quickly remove it by tapping it from behind using a long steel rod and hammer while someone slowly turned the damper with a wrench. It's fairly easy to see the damper from behind while paying underneath the engine.

I instaled a DynaSpark by DynaTech Engineering in Ft. Wayne, IN. It's a well made unit which I believe is worth the extra money over a GM stock replacement.

There are a few cautions when doing this project. When the shaft on the new OptiSpark is promperly lined up, the unit will fit snugly against the block. DO NOT FORCE IT IN PLACE BY TIGHTENING THE BOLTS! Make sure the Opti vent hose to the manifold doesn't rub against the sepentine belt. Take the time in this project to replace the spark plugs and wires, but be careful to route the wires properly using the exiting wires as a guide. Be sure to "burp" all of the air out of the cooling system by adding coolant, letting the engine warm up, and adding more coolant. I found it took about three cycles of doing this to get the coolant to the proper level while gettig all of thr air out of the engine's cooling passages. One big caution learned the hard way - be sure to have your face turned away from the drip pan when you drop the knock sensors into the antifreeze!

Good luck.

 

Here's a re-run:

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Get a Factory Service Manual, and follow the procedure it lays out.

A few tips (I'm going from memory here, so I'll probably forget a few things):

Drain the cooling system.

Disconnect the MAF sensor and IAT sensor and remove the air intake duct with the MAF and IAT as an assembly.

Disconnect the ECT sensor and remove it from the water pump.

Remove the serpentine belt and tensioner.

You may find that you’ll need to unbolt the coil/ICM bracket from the front of the right cylinder head. I can’t recall for sure whether or not I did.

Unbolt (but don't remove) the power steering pump. This will help you to sneak the new plug wires in/out behind the pump, but may also be somewhat helpful when working on the water pump/Opti.

If you want more room to work, you can remove the radiator, but it isn't strictly necessary, and it involves considerably more work to remove it (I left mine in place).

The FSM will tell you that you need a special Kent-Moore puller to remove the crank pulley/damper. You don't. Here's how to get it off:

1. Raise the front of the vehicle enough that you can get under the car (it's also helpful to have it at a more comfortable height while you're working from above).

2. Remove the three bolts that secure the pulley/damper to the hub.

3. Mark the damper and hub so that you can easily see how to realign them to each other later.

4. Slide under the car with a long pry bar or hardwood dowel (I use a jumbo Snap-On screwdriver that's around two feet long) and a mallet.

5. Place the tip of the pry bar against the rear face of the damper, as close to the hub as possible (Ideally rest the tip alongside of the hub).

6 Give the pry bar a few whacks with the mallet, and with any luck the damper will pop off without too much of a fight.

You may find it helpful to apply a few whacks, then rotate the crankshaft in 120* increments, whacking it a few times at each interval (I haven't needed to do this).

It's also helpful to, if possible, shoot a bit of penetrating oil where the damper meets the hub, a day or more in advance of doing the job.

After you get the damper off, clean the damper/hub mating surfaces to remove all corrosion, etc, and apply a very thin coating of anti-sieze compound to these surfaces before you reassmble the damper to the hub. This should make it a lot easier to get the damper off next time.

Once the damper is removed, rotate the crankshaft so that one wing of the damper hub is at the six-o'clock position. This will position the other two wings at around the ten- and two-o'clock positions. In this orientation, the Opti will clear the hub as it is being removed/installed.

The Opti basically unbolts and pulls off as you'd expect, once you have the water pump and damper out of the way.

Once the Opti is out of the way, inspect the shaft seals for the Opti, water pump, and crankshaft. If they show any signs of leakage, replace them now.

When you install the new Opti, be sure to align it correctly with the cam gear, and don't force it into place against the timing cover (do NOT use the bolts to draw it into place). At most, give it a gentle bump with the heel of your hand to encourage it to pop into place.

Reassemble everything else.

Follow the cooling system refill procedure in the FSM carefully, and you'll have no problems with this. In particular, be sure to bleed the air out of the system as it's being refilled.

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You are wise to replace the water pump and plug wires while you're in there. Definitely consider also replacing the coolant hoses, serp belt and plugs while you're in there, as well as doing a complete cooling system drain/flush (remove knock sensors to fully drain engine block). If you need tech tips on replacing plugs/wires, too, I can post 'em here.

Contact Chris May at Superior Chevrolet (1-800-728-8267) about a replacement OEM Opti. If you'd prefer to buy the best Opti you can get, consider the DynaSpark.

Hope this helps.

Be well,

SJW

 

Just take your time. It's pretty straight forward.

 

SJW - How many times do you think you have posted your directions?

 

Hard to say. I don't keep a count of such things. More than a few times, I'm sure.

I originally wrote my various tech tips up as Word documents, which makes it really easy for me to retrieve them and cut/paste into replies here, so I don't mind doing it. I'm sure it's easier for me to re-post 'em than it is for most folks to dig 'em outta the archives here. It's all in the interest of helping each other out...

Be well,

SJW

 

GMperformanceparts.com has good prices on new Optis. Don't go with a remanufactured unit

 

I recommend new OEM plug wires and water pump if your engine is stock. You can go with either a replacement OEM Opti, since yours is the much-improved second-generation Opti, or go with either the DynaSpark or new-to-the-market MSD unit, if you'd prefer to hedge your bets by installing the best unit available.

Below are some tech tips about replacing the plugs & wires on an LT1/LT4 Corvette. Perhaps you'll find this helpful, too, since you're going to tackle that chore as well.

Be well,

SJW

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Changing the plug wires on an LT1/LT4 Corvette is not a lot of fun, but it can be done. Here are a few tips:

1. Raise the front end of the vehicle to a more comfortable working height.

2. Remove the inner fenderwell center panel on the driver's side. This will allow you to both see and do the job much more easily on the driver's side. You may also find it helpful to remove the wheel.

3. Unbolt the ASR bracketry from the frame, so that you can slide the ASR unit around to get it out of your way.

4. Unbolt the power steering pump so that you can move it forward around a half inch. This will make it much easier to sneak the plug wires in/out behind the pump.

5. Remove the serpentine belt and tensioner.

6. Use dielectric grease in the boots at both ends of the wires. Be sure to "burp" the air out of the boots after you get each of them pushed firmly into place, so that the trapped air doesn't try to push the wires off later.

Some guys report that they've had decent success accessing the Opti-end of the plug wires from underneath of the car, and that this saved them the trouble of removing the belt and tensioner. I haven't tried this, so I can't comment.

Take your time, work with care, and pay attention to what you're doing. The OEM replacement plug wires from your Chevy dealer are high quality parts, and will route (and fit into the wire looms) correctly. Run the new wires properly, and make sure they stay away from anything that moves, is sharp, or gets hot.

The passenger's side is not such a bad job. The driver's side is a Queen Royal Beyotch (mostly because all of the belt-driven accessories are hanging on the driver’s side of the front of LT1/LT4 engines, and they leave little room for you to work or see what you’re doing). With plenty of patience, beer and Band-Aids, you'll get it done.

The spark plugs on the driver's side aren't so bad, when you've got things apart to do the wires. The passenger's side, however, is not so easy. The number 8 plug in particular can be a real headache, but with good tools and enough patience, you can get it done. Because there isn’t room for a ratchet on top of the spark plug socket, I use a plug socket that has a hex head on it so that it can be turned with an open end or box end wrench. It's useful to have more than one plug socket to choose from, as some will work better than others due to differences in length, wall thickness, etc.

Be sure to apply a small amount of anti-sieze compound to the threads of the new plugs before you install them so that they won’t seize in the cylinder heads in the future (this is especially important with aluminum heads). Just make sure none of the compound gets onto the electrodes or insulators of the plugs. I apply a very thin stripe of compound across the threads in one spot, and it spreads itself around the threads as I screw the plug into the hole. Also be careful that you don’t pick up any of the grunge that may have accumulated over the years around the spark plug hole in the cylinder head on the new plugs’ electrodes/insulators/threads while you’re installing them – try your best to get the tip of the plug straight into the hole on the first shot.

For OEM parts at great prices, contact Chris May at Superior Chevrolet (1-800-728-8267), and tell him you're a Corvette Forum member.