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No real point to this other than to post things I find interesting as I tackle a slew of maintenance items on my 93 with 47k miles. Finally getting off my butt and starting, no way I could even consider track driving without this…maybe it will help someone or motivate them to tackle these things. Maybe this belongs in “what did I do to my corvette today” . I might have some questions!
I bought the car in 2020 and have been chipping away at things every year. Now I’ve started really giving the engine some love. On the docket:
- pull and reseal intake (seepage at China wall)
- Replace water pump, thermostat, CTS and all coolant hoses, bypassing the throttle body.
- convert to smooth idler, tensioner and power steering pulleys with new belt
- pull opti, inspect and either replace cap rotor only with vacuum retrofit from petris or do the whole unit if it looks terrible or has a bad bearing (will keep mitsu sensor assuming it’s still oem)
- replace opti drive and water pump drive seals on timing cover
- new plugs and wires
- some other stuff I’m forgetting
- clean as best as I can in the garage
As of now I have all of the parts except the petris opti stuff.
It’s also getting close to me ordering new tires for my new wheels then stretch goals of lowering the car a bit and hopefully getting some J55s on the front + bias spring.
About to begin (what lurks beneath?) Throttle body leak? Uh oh…glad I bought a new CTS and never tried to remove that connector! Ummmmm…I guess that’s one way to stop the water pump from dripping in the opti This water pump was not long for this world…seal completely gone and grease flung out Found some of the seal… Opti looks like it avoided any coolant or oil, miracle! Can’t wait to pull it and inspect!!! Dirty but no intrusion
Yeah I should have done this sooner!
next up is getting the crank pulley off…bolts are out but needed to clean and dry the floor before I get under the car to try and knock it off.
Opti coming free… crank pulley came off surprisingly easily…long dowel rod from underneath with a 4 lbs hammer and off it came Timing cover looks good IMO..just dirty and wet from coolant Encouraging! Back side doesn’t look too bad. The part that needs to be clean is clean. Hmmm…maybe it’s ok? Cap…one of the thin bolts that holds the cap on snapped…fixable Rotor worn Cap electrodes worn Uh oh…both screws were so corroded a little twist and they disintegrated (not just snapped…complete crumble) Oh…oh no… Dead. But what’s this symbol! Score!! It’s original! Also the wheel where it matters is perfect. Might as well pull the PS pulley now This tool is a rental from Advanced…worked effortlessly! Going to wait a until I have wires, plugs, intake etc to install the new pulley
So I guess this is evidence that active venting likely matters a lot…time to order a full petris and I’ll hang onto that old sensor for sure. Glad I didn’t try and order just the cap/rotor/vent kit…it’s obvious any other screw or bolt I touch to disassemble further will disintegrate.
Btw car had no running issues whatsoever. This isn’t totally surprising as the wheel and sensor were fine…it’s just everything else around it. No way I am putting that back on.
1- 93 with 47K, but you are not the PO.
2- No idea if POs ever decided to pressure wash the engine3- Do you have to remove the entire Opti to replace the rotor and cap?
4- Did you clean behind the Opti before the pics? I would have expected lots of oil back there.... Looks very clean.
5- What is the stuff inside the Opti...4th pic?. Looks like chewed up plastic?
6- the bolts disintegrating...wth? Can the remains be removed? Where do you get new hardware?
7- The rotor looks pitted to hell!?!?
8- Are you sure the corrosion is ozone and not water damage?
9- You stated your car ran good. I'm really curious to hear how it runs after the new Petris unit.
10- What's the deal with the pulley? I have any LT4... Do I have a sanity pulley? Can't remember.
Ignition wise, this is the last thing I need to do to my car... Cap and rotor. I'm having second thoughts. 😬
@IHBD I agree it’s the unvented ozone that does it, at least on mine. Sorry to hear about your struggles, I have the seal install tool for the WP seal so hopefully that will go well. I was going to lather with assembly lube but if the inner lip is Teflon that might not be right as I believe those are supposed to go on dry? I will check. Thanks for the warning on the pulley, I will try not to screw that up…
Another forum member asked about the old pulley already so I will PM him, if that doesn’t work out I’m sure we can work something out.
I went with the after dark speed pulley…seems very high quality.
@rremesal “1- 93 with 47K, but you are not the PO.”
Correct.
“2- No idea if POs ever decided to pressure wash the engine3- Do you have to remove the entire Opti to replace the rotor and cap?”
No idea…but it doesn’t look like it was washed ever. Appears untouched. No you don’t *have* to remove…although the rotor screws would be hard. It is almost zero difference in effort to completely remove the opti to freshen it…in fact it would probably be easier and shorter time. Less chance to break anything too. 3 bolts and it’s off and remember one of the tiny cap bolts snapped so you’d want to take care on a bench.
“4- Did you clean behind the Opti before the pics? I would have expected lots of oil back there.... Looks very clean.”
Nope. Taken immediate after removal.
“5- What is the stuff inside the Opti...4th pic?. Looks like chewed up plastic?”
I believe it is the material/corrosion coming off of the electrical pins in the distributer…there is nowhere for that to go so it accumulates there.
“6- the bolts disintegrating...wth? Can the remains be removed? Where do you get new hardware?”
The rotor screws are Phillips head. I am sure you could drill and retap or maybe I could unscrew with vice grips (assuming the shaft doesn’t snap). But you’d want to remove ALL of the screws/plates and either get some thing sheet metal to try and replace by hand forming maybe? Problem is that metal that is rusted is paper thin so I doubt they could be reconditioned. The opti wheel should be fine though.
“7- The rotor looks pitted to hell!?!?”
I’m not sure that’s abnormal for 47k miles.
“8- Are you sure the corrosion is ozone and not water damage?”
99%. As you can see there is no evidence of intrusion of water or oil whatsoever.
“9- You stated your car ran good. I'm really curious to hear how it runs after the new Petris unit.”
I doubt it will make a difference OTHER than the strength and quality of the spark…I was originally assuming I could do just cap and rotor unless the opti had it gotten water/oil in it (or a bad bearing)…well that didn’t matter.
“10- What's the deal with the pulley? I have any LT4... Do I have a sanity pulley? Can't remember.”
92-early 93 used a belt that was ribbed on both sides. This means the idler, tensioner and PS pulleys are also ribbed instead of smooth. This decreases the availability of belts significantly and makes them more expensive. Also the updated design fixes some issues (which I don’t have) so I decided to swap it all out. Why pay extra to buy a new tensioner and idler + belt (which all cost more than the updated stuff) and stick with a belt I cannot just run to a local parts store to grab? Yes I’m spending more but to me it’s insurance, especially if I end up doing a track day some day.
Btw, the whole Opti concept is very disappointing. Not only did they pick the worst spot, the also used the cheapest materials possible.
Everything in there should have been plastic, aluminum, AND stainless steel or other corrosion resistant material. The rust I'm seeing in your unit is bad. Hardware simply disintegrating is just scary.
This is an excellent post. Thank you for sharing. I have a 92 with 68k miles on it. Im guessing my opti looks similar. Kind of scary to think about.
Honestly mine probably would have just kept chugging along for a while longer. Even though it looks that bad, the parts that are super rusted serve no active function. As long as the wheel stays clean and nothing physically breaks it would just keep going. The rotor screw shafts were still strong and as long as it’s left undisturbed it’s ok.
BUT if it’s an original 30+ year old NON vented opti expect to replace it IF you are going in anyway. The issue comes when you need or want to service it or pull it for any other reason. I know the mitsu sensors are “the best” but…there is a useful life for the rest of the stuff and at some point the cap and rotor have to be done.
Honestly mine probably would have just kept chugging along for a while longer. Even though it looks that bad, the parts that are super rusted serve no active function. As long as the wheel stays clean and nothing physically breaks it would just keep going. The rotor screw shafts were still strong and as long as it’s left undisturbed it’s ok.
BUT if it’s an original 30+ year old NON vented opti expect to replace it IF you are going in anyway. The issue comes when you need or want to service it or pull it for any other reason. I know the mitsu sensors are “the best” but…there is a useful life for the rest of the stuff and at some point the cap and rotor have to be done.
I too have a 1993 but mine is slightly late built than yours. I say that because I have the newer belt design AND the hood has a Mobil 1 sticker instead of the Bowling Green plaque. Pretty sure that change happened midway through ‘93 as well. I have 32k on it and am third owner. Bought from second owner via a”broker.” All I know is the car lived in RI from ‘99-2022. I’m sure mine will look very similar to yours when I eventually take it apart. Thanks for all the great info really appreciated!
Yes I ordered it this morning, I wanted to pull things apart before pulling the trigger. As others said I am not going to take it apart since it would void the warranty. FWIW I have exchanged several emails with Chris Petris and he seems to be a standup person and was helpful and informative.
Didn’t get to touch anything else today, except swapping the rear knuckles on my rc car to aluminum (I don’t think that counts lol, broke one of the stock plastic ones). Tomorrow going to try and get the front of the engine cleaned off, maybe seals swapped and then either start trying to do the spark plugs/wires or the intake pull… I am thinking intake last as I do not believe it will help make the plug job any easier and would leave things exposed longer. I will definitely do the intake before the water pump, pulleys, new hoses etc go on so I have more room to work with.
I have a feeling the spark plugs are original, should be interesting and hopefully no surprises!
Wife is sick right now so I have full house/kids/dogs/hamster duty…so it may slow me down but I’m waiting for the opti anyway.
Tried to install the water pump drive shaft seal with the tool. That part was fine. Used copious assembly lube. But…lighting wasn’t great so with the shadows I didn’t realize I had the seal slightly cocked as I was driving it in… I leveled it but didn’t feel great about that. Also I didn’t attempt to clean up the shaft with sandpaper/wet sand it. Is that necessary? Just de burr? Do I need to worry the spot where the seal actually rides?
also just to be sure should this seal be “bottomed out” or flush with the cover?
I have a another new seal on the way. Cheap enough I’d rather do it one more time to be absolutely sure. Maybe I’m being too paranoid?
So while I’m waiting, I’ve been doing more of a deep dive on the cooling system with additional flushing.
This is my third attempt flushing the system since I bought the car. First time when I got the car it was absolutely putrid…maintenance people!!!! This weekend I flushed the radiator with a hose, flushed the heater core (second time since fall) etc.
I pulled the expansion tank and wow was it full of junk (even after some flushing in the car). I probably filled/shook/emptied the thing in the sink for 20-30 minutes straight. Gunk and rust flakes just kept coming out. Suddenly it started to rattle when I shook it…I bet the coolant level sensor had been stuck and finally let free.
Surge tank just after removal and after it had been flushed in car, puking in the sink:
after seeing this I highly recommend pulling that surge tank if the cooling system is in need of serious flushing. It wouldn’t come out without shaking.
Very glad I’m replacing ALL of the hoses too, PO(s) did me no favors:
Now what about the radiator with that much junk? It’s been fine…no leaks and no overheating…flush is running clear…so I guess I’ll just run it and hopefully save some time and money for now.
Based on the flushing it seems like almost all of the junk was in the surge tank and as a result some in the heater core
Interesting. My car does not overheat, but it takes a long time for great to come out of the vents. I wonder if the heater core and hoses are clogged in a similar fashion as yours.
Getting ready for spring
. I might have some questions!
