Robyn Knott

Hi, I just had my opti spark replaced and now for some reason my car is overheating and looks as if I have an oil leak and just had new wires, plugs, injectors new oil filter housing and new oil change. I'm getting codes 16 and 36 and all I have found is to clean opti please help don't want to mess my baby up my ex husband tried and has cost me nearly $1500 to get her running

Injuneer

Where is the oil leaking? An Opti install requires removing the water pump. That exposes the water pump drive shaft seal in the timing cover to damage. If the seal is not replaced, or replaced incorrectly, oil will leak out above the Opti. Additionally, installing the Opti requires replacing the seal in the timing cover for the Opti drive shaft. That can leak, oil can enter the Opti, and interrupt the pulse signals from the optical cam position sensor in the Opti.

DTC 16 and DTC 32 set when the pulse signals from the Opti are interrupted or irregular.

Does the engine start easily, and idle and run smoothly? Does the engine seem to have normal power, or is it sluggish? When DTC 16 sets, the ECM will shut down the fuel system, and the engine will shut down and not restart. If it restarts, the code is not “active” but is stored in the ECM.

By overheating, what is the temperature showing on the dash gauge? Does the needle go into the red? Some people remove the electric radiator fans to replace the Opti, and they may have failed to reconnect the harness, may have blown the inline “fusible link” that powers the fans, damaged the harness, etc. The ECM turns the fans on and off based on the coolant temp sensor that is mounted in the water pump housing. That sensor may have been damaged, and not be reporting the correct temp. If it was left disconnected, it should set DTC 15 for the open circuit.

What brand is the Opti? Most of what is available, particularly at low price, are Chinese made junk.

Germansheperd

Possible the cooling system wasn’t bled properly when the water pump was removed to install the opti and it has air in the cooling system and that is your overheating issue?

BTC

Looks like everything I would have mentioned has already been covered. The cooling system probably wasn't bled properly, and/or perhaps wasn't refilled, and the water pump and opti seals likely weren't replaced, weren't replaced properly or were damaged. The seals in the timing cover can leak like crazy, and in my experience the water pump drive shaft seal in particular.

This is off topic, but I used to live in Dalton & Atlanta. My first job out of college was as a computer programmer for Shaw Industries.

Robyn Knott

The oil looks as if it's coming from everywhere. I can't tell if I have a new oil filter housing or not oil looks like it's coming from there as well as the opti. The car will like die and come back on with check engine soon light on. I don't know what the opti is. The mechanic who has done all this work is giving me a hard time about the work order. Now it feels like a wheel is coming off. I'm scared to take it back. The codes I'm getting are 15, 16 and 36

Injuneer

The oil filter is under the engine, driver side of block. The “Opti” is the OptiSpark ignition distributor, bolted to the front of the engine, under/behind the water (coolant) pump.

Two of the codes, DTC 16 and DTC 36 indicate the PCM (computer) is not receiving the data from the “Opti” that it needs to run the engine. If DTC 16 is “active” (as opposed to a code from the past that is “stored”) the engine will not start or run, because the PCM shuts down the fuel system (injectors and pump).

DTC 15 indicates a problem with coolant temperature sensor, which is screwed into the water pump, right in front of the “Opti”. Most likely they forgot to reattach the harness connector to the sensor when they replaced the “opti”. The PCM needs the coolant temperature to control the radiator fans, but with DTC 15, the PCM should default to running the fans all the time. Are they running, even when the engine is cold? If they are and it is still overheating, the (alleged) mechanic may have forgotten to install, or correctly installed the water pump drive shaft. And as noted in a post above, failing to bleed the air out of the LT1’s “reverse flow” cooling system can cause overheating.

Sounds like your mechanic may not be very familiar with an LT1 engine.

Clear the codes by pulling the “PCM BAT” fuse, in the fuse panel on the driver side end of the dash, for 30 seconds, then replacing the fuse. Try and start the engine, being sure to crank it for an extended period to see if the codes reset.

DTC 16 and DTC 36 can be set by:

- defective optical cam position sensor in “Opti”. Even a brand new Opti, right out of the box can be defective, since most of them are cheap, poor quality, Chinese rip-off copies of the original.

- an oil leak into the Opti from the seals in the timing cover can cause the oil to coat the optical cam position sensor and prevent it from working.

- corrosion, damaged harness connector pins, broken connector locking clip, or damaged harness wire on the short harness that runs from the gray connector on a bracket on the passenger side of the intake manifold, to the Opti.

If he says a wheel is “coming off”, ask him to show you, and then tell us what he showed you. “Coming off” is an extremely vague description.

ray42

Robyn,

If you can get the oily places clean again, do that, and then spray those places with aerosol body powder spray. The powder will show you where the oil is coming from soonest, before the oil goes everywhere. You may not even need to drive it then; the oil leak may appear in the powder when idling, or revving the engine in Neutral. Drive it briefly, and check the powder for oil frequently, until you can nail down the source(s) of the oil. There will be no problem with longer drives, of course, but you may need to start over with the clean & powder process, if much oil is leaked. Mark the edges of the spreading oil stain with dots of any paint (even nail polish) at the leaking seams, so they won't be forgotten later.

I can't really help with the OptiSpark, but from my experience, most of the cheap units are indeed junk. I took mine (94 Trans AM, LT-1) to a real hot-rod shop. They got the right aftermarket OptiSpark unit ordered in (and installed correctly) and I had no further problems with it. Costs were as expected, sure, but not excessive. Many mechanics now do not know enough about OptiSpark units to say which ones are good or bad. I wanted to know what brand of OptiSpark they put into my TA, but the hot-rodders do have their secrets, so I didn't press the issue. They said I'd be happy with it, and that was true.
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plattted

SOME EXCELLENT ADVISE HERE! I also have a '93Z and have replaced the OPTI several times and the notes mentioned here are right on!

Clean the oily areas with rags until all the oily residue is gone then start the engine for a less than a minute, then check under to see if there is oil is still leaking.

The above notes will help. Could be just a not tightened oil pan drain plug, or a not tightened properly oil filter.

The seal on the water pump is another area of concern.

Do not run that engine with out proper oil levels!