optispark question
Thread Starter
Instructor
Joined: Aug 2001
Posts: 129
Likes: 0
From: Millington Mi
optispark question
I've heard a lot about the optispark on LT1 engines. I'm just not exactly sure what the problem is.
1st of all: what is the optispark and what does it do?
2nd of all: why is it such a common problem?
3rd of all: I've heard that water can break it... does this mean I can't clean my engine?
sorry if these are dumb questions but please bear with me. I'm a new owner.
1st of all: what is the optispark and what does it do?
2nd of all: why is it such a common problem?
3rd of all: I've heard that water can break it... does this mean I can't clean my engine?
sorry if these are dumb questions but please bear with me. I'm a new owner.
Drifting
Joined: May 2001
Posts: 1,297
Likes: 0
From: Edmond Oklahoma
Re: optispark question (Bradley33)
The OptiSpark is essentially a high-zoot distributor.
It's a common problem primarily (in my opinion) because it is located in a bad spot right behind the water pump and by the crank pulley. Water pump leaks and throws 200+ degree water on the pulley and the pulley slings it most everywhere. An old distributor wouldn't mind this mush, but the Opti does more than a distributor. Whereas the distributor only knows which plug to fire, the Opti knows each degree of crank rotation so it can do a lot of neat stuff.
The later model cars have better venting to keep the Opti dry (yours may have been retrofitted if there is a vacuum tube coming out of the air inlet behind the MAF). Sealing it completely does not work.
As for cleaning the engine, that's a personal risk issue. I've cleaned the fire out of several LT-1/4 motors without incident. By cleaning, I mean soaking them with Simple Green and then using a 1400psi pressure washer. Other folks have worse luck and even spilling a soda in the garage appears to cause their Opti to puke. Better to be lucky than good.
Again, it's just my opinion, but if the car runs fine and isn't leaking from the water pump (look with an inspection mirror at the bottom of the water pump right above the crank pulley) you really aren't helping anything by worrying about it. Keep a regular eye on the water pump and when it starts to leak immediately replace it with an electric pump before it hoses the Opti. The electric pump costs the same as the original and gets rid of the leak.
If the car is hard to start or has other symptoms of a bad Opti, either save up the $$$ to have it done and upgraded to the new style or do what I'd do and reach for the toolbox.
Mark
It's a common problem primarily (in my opinion) because it is located in a bad spot right behind the water pump and by the crank pulley. Water pump leaks and throws 200+ degree water on the pulley and the pulley slings it most everywhere. An old distributor wouldn't mind this mush, but the Opti does more than a distributor. Whereas the distributor only knows which plug to fire, the Opti knows each degree of crank rotation so it can do a lot of neat stuff.
The later model cars have better venting to keep the Opti dry (yours may have been retrofitted if there is a vacuum tube coming out of the air inlet behind the MAF). Sealing it completely does not work.
As for cleaning the engine, that's a personal risk issue. I've cleaned the fire out of several LT-1/4 motors without incident. By cleaning, I mean soaking them with Simple Green and then using a 1400psi pressure washer. Other folks have worse luck and even spilling a soda in the garage appears to cause their Opti to puke. Better to be lucky than good.
Again, it's just my opinion, but if the car runs fine and isn't leaking from the water pump (look with an inspection mirror at the bottom of the water pump right above the crank pulley) you really aren't helping anything by worrying about it. Keep a regular eye on the water pump and when it starts to leak immediately replace it with an electric pump before it hoses the Opti. The electric pump costs the same as the original and gets rid of the leak.
If the car is hard to start or has other symptoms of a bad Opti, either save up the $$$ to have it done and upgraded to the new style or do what I'd do and reach for the toolbox.
Mark
Instructor
Joined: Jan 2001
Posts: 195
Likes: 0
From: Kenosha, WI USA
Re: optispark question (Bradley33)
Hey there - everything "vanduker" says is true - my '92 crapped out after I washed down the engine compartment with the engine running - posted a query on the Forum - got a lot of good help in addressing my engine out situation. Figure the damper pulley or the electric fan just threw that water around when I washed her down - bad move!
Just pulled my Opti yesterday - all the seals looked good on the outer and inner covers - there were some typical arcing/corrosion products on the distributor contacts and the rotor, but the big surprise was when I pulled the covers to get to the timing wheel - the LED emitter/receptor screws were damn near rusted away - the inner cover over the whole shebang is metal and had a severe case of corrosion as well - especially where it is near the "infamous" three weep holes located in the bottom of the aluminum casting. My new Opti is on order -
Remember, the guys here say it depends on mileage, but it also depends on age and whether you drive the car in the weather - I do, so barely 60K on the clock was enough to ruin mine - in hindsight, if you can get an dental inspection mirror routed in there behind the damper and shine a flashlight on it, look at the three weep holes on the bottom of the Opti - mine had the orange telltale rust coming from them - if you can see up in there, that would be your best diagnostic to see if your time has come as well!
:yesnod:
Just pulled my Opti yesterday - all the seals looked good on the outer and inner covers - there were some typical arcing/corrosion products on the distributor contacts and the rotor, but the big surprise was when I pulled the covers to get to the timing wheel - the LED emitter/receptor screws were damn near rusted away - the inner cover over the whole shebang is metal and had a severe case of corrosion as well - especially where it is near the "infamous" three weep holes located in the bottom of the aluminum casting. My new Opti is on order -
Remember, the guys here say it depends on mileage, but it also depends on age and whether you drive the car in the weather - I do, so barely 60K on the clock was enough to ruin mine - in hindsight, if you can get an dental inspection mirror routed in there behind the damper and shine a flashlight on it, look at the three weep holes on the bottom of the Opti - mine had the orange telltale rust coming from them - if you can see up in there, that would be your best diagnostic to see if your time has come as well!
:yesnod:
Burning Brakes
Joined: Aug 2001
Posts: 893
Likes: 0
Re: optispark question
As another new Corvette owner, I hope you don't mind followup questions:
(I am also very ignorant about automotive mechanics)
Where is the optispark unit and what does it look like?
If I want to wash the engine, can the optispark be temporarily covered with
plastic (and taped closed)? Is there anything besides
the Optispark that should be avoided when cleaning the engine?
(I am also very ignorant about automotive mechanics)
Where is the optispark unit and what does it look like?
If I want to wash the engine, can the optispark be temporarily covered with
plastic (and taped closed)? Is there anything besides
the Optispark that should be avoided when cleaning the engine?
Melting Slicks
Joined: Oct 1999
Posts: 2,501
Likes: 177
From: Houston, Texas FEAR THE BONES
2023 C5 of the Year Finalist - Modified
Re: optispark question (knp)
The Opti is the distributor on all LT1 and LT4 engines (1992-1996 non-ZR-1's)and is located on the front of the engine directly beneath the water pump and behind the crank pulley. It is a flat black unit about the size of a VHS tape. It is an electronic distributor, so the plug wires plug into it, along with the coil wire. It also has an optical sensor that reads crankshaft position for the optimal ignition firing parameters. It is NOT recommended you wash the engine as water can get into the Opti and ruin it. I've gone through 2 already (just changed it out last weekend) with 81,000 miles.
