teamstream

well, im not totally positive, but think my opti is bad. anyone have any step by step instructions to change it ? wasnt sure if anyone had anything made up on changing one. I think im gonna try it myself.

96LT1TX

I would do a search here, it is the most common repair done on our motors.

Basically though, for me I drain the coolant, pull off the intake to the throttle body, pull off the electric water pump, pull off the water pump, pull off the plugs/connectors, pull off the opti, replace, go in reverse order.

If this is your first time bring some beer.

I have the process down to ~4 hours if I have the proper ammount of beer + music + good weather. The first time I believe it took me like 10 hours.

teamstream

what about the harmonic balancer? friend said he pulled his off and not the waterpump. its a 94 camaro...not sure if the 95-up are any different

Drew24

yeah your going to have to pull the harmonic balancer pulley off but it is really easy just go to an autozone and rent a harmonic balancer puller. You pay like 20 bucks and when you return it they give the 20 bucks back. The thing that helped me when pulling it i didn't use the bolts that the pulley puller came with i used the bolts that hold the balancer on. Good luck and bring lots of beer

mfb_lt1birdman

Be sure to get a new GM opti.

It is straight forward. Biggest pain is the coolant getting everywhere and having to dispose of it. Once you drain the hoses and radiator remove the bottom right (drivers side) WP bolts to get a bunch more fluid from the block.

You will probably need a wobble socket or adaptor to get to the one short WP bolt thats kind of behind the belt tensioner.

I would suggest labeling all your plug wires prior to pulling them off. Then marking the new opti with the cooresponding numbers. I know the optis have the raised numbers on them but they are hard to see under the car.

While there if you have any front seals leaking oil, especially the dreaded WP drive seal, now is the time to do it.

Injuneer

You should do a thorough analysis of the problem, before jumping to the conclusion that its the Otpi. Too many times people make the Opti assumption, and end up spending money on an expensive part they didn't need.

What are the symptoms of the problem? What have you done so far to track down the cause? Provide details of the car - year, model, engine, tranny and any major mods.

teamstream

well, i have checked the coil, icm, fuel pressure, and compression and all is good. i pulled the #1 and #3 plug out and noticed they were overgapped and read .070. I grounded the plug and turned it over and it sparked every so often, not like it should have. then realized a few plug wires were backwards and i thought maybe i had figured out, but still no start. i bought new plugs today so im gonna change them and see what happens..i dont think its the problem, but definetly worth doin since the old ones are gapped to much. Its a 94 z28 camaro.

96LT1TX

I will say "no start" is rarely an opti issue unless you had a loud pop last time you were driving and it hasnt started since.

teamstream

well...i got the car running. i just put new delco plugs in it. it does have a slight miss. i swapped a couple plug wires cause i thought a couple were backwards. are the plug wiring diagrams the same on the 94 opti's to the 95 when they changed? i would assume so..but didnt know

Injuneer

The plug wire connections are identical on all Optis.

Courtesy of Shoebox:

http://shbox.com/1/opti.jpg

Is it possible you had the original AC Delco platinum plugs? They had a habit of losing at least one of the little platinum pucks, opening up the factory 0.050" gap to 0.070".

Have you checked the plug wires? Have you checked the Opti plug wire towers and wire ends for corrosion?

teamstream

it had the acdelco part #14 plugs in it...were they factory? thats what i put back in it as well. the car has 140k on it. i just bought a set of new plug wires , gonna change them tommorrow. what do you mean by the opti plug wire towers?

Injuneer

The parts of the Opti where the plugs wires and the coil wire plug into.

HerbzHancock427

you dont have to pull the harmonic balancer when changing the opti. I just did mine last night, and I just took the dampner off and turned the crank hub until the "Y" was up and this gave me enough clearance to pull it off.

RUDEDOG

The harmonic balancer and the damper are the same part.

Injuneer

I think what he meant to post is you don't have to pull the damper/pulley AND hub off the crank. Just remove the damper/pulley from the hub, leaving the hub in place. In theory, it should fall off when you remove the three bolts, but rust builds up bad enough that you often have to use a 3-jaw puller to get the damper/pulley off the hub.