what is involved in changing an opti spark i have to do it my self

 

Easy job. Loosen the gas cap to relieve pressure and remove the right front tire. It's all down hill from there.

OK, you started it...

Do an advance search and limit the category to C4. There are plenty of good write-ups available. It isn't terribly complicated. The biggest challenge is probably removing the balancer from the front of the crank. It's nothing that a hammer and a block of wood won't conquer.

Good luck. There is lots of debate on which replacement unit to go with.

 

http://forums.corvetteforum.com/c4-t...-pictures.html

Some will recommend only ACDelco, but I have replaced 4 of those, so I'm not a fan.
Just installed Procomp from SacCity Corvette..... we shall see.

Good luck!

 

thanks guys

 

As mentioned the balancer can be a real pain. Spray it down with PB blaster. Since you have to remove the water pump it's a good idea to replace it while your at it and add a drain tube to the weep hole. Get a timing seal kit and replace the seal for the WP and opti. Be sure to use the tool when installing the WP seal.

 

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.

If you're replacing the plug wires while you're in there, (recommended, unless they're fresh) 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. Some have one bleed screw, some have two. Be sure to bleed both if there are two.

Live well,

SJW

 

The really nice thing about the process is that there are dowels sticking out on the front of the block to help you "hang" the water pump into perfect alignment. Removing the belt tensioner really helps when dealing with the passenger side spark plug cables. Replace the timing seal, like the previous poster said. There is a youtube video out there on how to do that without ruining the seal. I could not get enough swing to wack the harmonic balancer off, so I loosen the power steering line and use a 2 arm puller. When using the puller, I put a 3/8" to 1/4" adapter in a short 3/8 drive socket, insert it onto the center bolt of the hub, and let the puller bolt set into the 1/4" part of the adapter to keep the puller centered. The tie wrap is to keep the arms in position.

 

wow that is alot of work i am having 2nd thoughts

 

Its really not once you get into it, just stay focused on your task and don't get caught up in replacing things you don't need right now. Use the link that was posted above I did and it works great.