Thanks a million for the reply. Despite years of tinkering with many a car, truck and motorcycle, I frankly don't know where I'd be with my C4 without the Forum and folks who are willing to share like yourself.

This is my first OptiSpark replacement. I've taken apart the new replacement I bought and with one of the case bolts and one of the rotor bolts arriving with messed up heads, am not impressed. I do believe I'll lay down a bead of silicone on the theory it can't hurt.

I couldn't ask for the car to run any better. Still without knowing whether the Opti has ever been replaced but being doubtful based on the other maintenance I've run across (and corrected) and with at least one long trip planned in the next month, I'm looking forward to pulling the old one and seeing what shape it's in. And I'll be replacing the water pump as well.

Thanks again!

John

Thanks for the great write up .the picks were great this is the reason i love this forum

first time seeing this.

Bookmarked.

Thanks a BUNCH, fantastic writeup.

An awesome article! The electric water pump is the way to go too. My '92 has 82,000 miles on it and so far I have been lucky but know that this is what I will have to face one day. I have copied your article, including colored pics, and will use it when the time comes. Thanks again for your fine work!
Bernie

I'm rocking along, everything is taking longer longer than I hoped but that's par for the repair project course but now I've run into a problem with

I've removed the 3 bolts but how do I "knock the pulley loose"? I assume perhaps by using a thin piece of wood inserted from underneath the car from the rear above the crossmenber and alternate hits from left and right. Am I on the right track?

Thanks in advance!

John

Yep, just be careful not to hit it on the outer ring and damage the dampner.

I've never tried it but some have loosened the three bolts a few turns and fired up the engine for just a few seconds or so. It will jar the pulley loose, supposedly. The belt is removed for this.

Yup, you're doing just fine.

It'll take a bit of persuasion, but eventually the crank pulley will slide its way off the hub. I used a small mallet and a length of 2x2 I had laying around (though I'm sure a 2x4 will work just as well) As was already mentioned by STL94LT1, avoid hitting the pulley from around the outside edge or you risk damaging it. The higher your car is off the ground, the easier it is to get a good "swing" with the mallet.

The trick is to try and keep the pulley itself as straight as possible when you're knocking it loose. Hit it a few times on the left side, then the right side, than back on the left again. Be patient, it will eventually come loose. Later on when you go to reinstall the pulley, be sure to clean it thoroughly, removing any rust that may be on it, then apply some anti-seize compound to prevent the pulley from getting seized in the future.

Hope this helps. :)

Thanks a million for getting back to me. No luck yet but maybe tomorrow will be the charm.

John

Should be a Sticky/.

Here's an update to those of you who might be following my progress.

Thanks to everybody (and especially LT1*C4) who told me to not give up and just keep after that crank pulley, it f-i-n-a-l-l-y popped loose late this afternoon. I really wanted to pull the Opti and get some degreaser on the front of the engine but it's been a long couple of days so that's tomorrow. Based on the water pump's condition, my difficulty knocking the crank pulley loose and the grease on the front of the engine I'd guess both the water pump and Opti have been in there for the full 162k ride but I'll have a better guess tomorrow.

Again, many thanks!

John

Best write up I have ever seen. *subscribed.*

Any tricks on how to remove the old gasket from the block? These thing wiiiiilll not come off...

Thanks to all who replied and helped me keep pushing forward. For me this is now a project marked "Done". I replaced the Opti and water pump and also driver side valve gasket cover, thermostat and spark plug wire set since all are easier with the serpentine belt and other paraphernalia "off". Here are a few of my thoughts.

First, this seems like a little thing but I'd buy a box of vinyl gloves before starting as this is a messy project.

Second, altho I understand “knocking the crank pulley loose” is the accepted way of doing things, if your car has the rust mine had creating a virtually impenetrable bond between crank pulley and hub (I repeatedly used both PB Blaster and Liquid Wrench with no success), I frankly worry about doing as much hard hitting as I did on the crank pulley and hence the crankshaft. I sanded both the crank pulley and hub clean and really slathered both with anti-seize so maybe next time it will be easy (FSM, of course, has a detailed procedure including lifting the engine off the motor mounts whereas Haynes says you didn't even need a puller).

So while the experience was fresh in my mind (and the crank pulley was available to use for measurements) I bought a low profile puller (Astro Pneumatic #78514 but OTC and Lisle make ones that look identical) and had a machine shop chop off each leg and re-drill for the mounting pin to make it "lower" profile. (Incidentally the author of the thread has a '92 and I have a '94 - both LT1's - which I would assume would have the same configuration but I had plenty of room to lift out my crank pulley before removing the Opti and he didn't.)

Third, I didn't completely drain the coolant before pulling the water pump and won't make that mistake again.

Fourth, think carefully about doing all this work and then installing a bargain Opti. I'll elaborate.

The accepted wisdom on the Forum and elsewhere seems to be that two "improvements" will increase the Optispark's chances of a long life, those being using thread locker on the tiny rotor bolts to prevent their spinning loose and second, running a bead of RTV around the case as the seal frequently cracks in the heat and thus may admit moisture and dirt. And when I pulled my old Opti both of these problems afflicted it. One rotor bolt was being rocketed around by the rotor and there many cracks and missing sections of seal and lots of debris inside the case.

When I attempted to remove the cap on the new "phenomenally low price" Opti I bought from MAM I found one of the deep-set 3A Torx bolts heads stripped. Fortunately by working with it I was finally able to remove it and could substitute one of the bolts from my old Opti. But once inside the new Opti I found both of the rotor bolts loose and the head of one would no longer permit using a T9 bit. After finally getting it loose I was able to find two new rotor bolts (the replacement bolts were Allen head rather than Torx but that was fine).

But then there was a third problem: I couldn't find the key-slot in the spline. It's quite easy to see on my old OEM Opti and I finally found what appeared to be the key-slot on the new Opti and was able to coordinate it with the key-slot and rotor position on my old Opti. (Frankly, the key-slot on the old Opti looks as though it was part of the milling process; on the new Opti it looks like a crude after-thought.)

New Opti problems solved, I applied thread locker to the rotor bolts, RTV to seal the case and was ready to install first thing the next morning when I tossed and turned all night feeling uncomfortable about the MAM Opti.

It's advertised as "a phenomenally low price" but I ultimately decided that wasn't a sufficient trade for the problems I found or other problems I hadn't yet found. Perhaps my MAM Opti was the one in a thousand that had a few problems and other buyers won't have the same experience I did. But I bought and installed instead a Delphi OEM Opti from thepartladi (about $40 more than MAM, shipping included in both prices) and wrote MAM telling them I wasn't asking for my money back since I'd made the decision to go with their product but I did hope they'd consider whether it was up to their standards. I was a little surprised not even to get an acknowledgment back from MAM. You can take my experience for whatever it's worth.

John

This should be made into a sticky. Too much info. not to save it..

Great post.

trebor

Purchased this from my snap on guy :D did the trick :D

Attachment 48155811

I know this is an old thread but it really should be a sticky! I just did the water pump/opti and the pics were an enormous help!

Very nice,

For someone like myself whom doesn't know much about how to wrench his own car, this helps alot ..

Thank you for the time you took to post/upload all this great info

:iagree::iagree::iagree::iagree::iagree: :iagree::iagree::iagree:

One of the best write-ups ever, plemty of people have said the same, why it isn't a sticky is beyond me :willy:

excellent writeup ill definitely use it soon when I replace my opti