Anyway to check if I have bad opti? Other then scanning it? My car is running real rich and I have a feeling its not the O2s. My mechanic said he hears a bearing noise coming from either the waterpump or opti. My car overheated and overflowed coolant but my waterpump did not go but we replaced it anyway. So Im not sure if its my opti thats causing my car to run rich. Also does anyone elses car run worse when its rich? My auto teacher touched the inside of my exhaust and it was black so he said that means its rich. I got about 700-800 and I want to do electric electric water pump, opti, and plugs/wires, but I also want my MAC headers. Don't know what to do, anyone have any ideas?

 

an opti issue won't cause a car to run rich, it will cause it to stumble, or perhaps just die.

You may want to do your normal tune up stuff..plugs, wires, etc.

If you have access to a scanner or datalogger, perhaps you want to plug your car into a computer and watch the variables. You should see the o2 sensors go crazy if they are healthy...their readings will jump from 100 to 900 and everywhere inbetween.

 

All LT1s have some soot on the inside of their tailpipes. They run rich.

 

I dont mean to sound totally stupid, but what will stumble feel like? Will it be at idle? acceleration? Thanks guys.

 

Stumble will occur under load, have you ever been walking and stumbled over some thing, thats what its like but with the rpms. When my intake elbow was torn at high way speeds the rpm would drop real low all of a sudden and then pick back up. A miss is when you put your foot on the gas and the car does nothing, but then will accelerate like normal. You can feel the miss, and you can definatley feel the stumble. If some thing is bad like an a/c comp has a bad bearing and its making a lot of noise, the car will pick it up as knock and through in a lot of fuel in. Your opti wont make noise, I dont think your mechanic knows what hes talking about. A bad water pump will throw up coolant real soon. Does the car have the service light on? If so check codes and you'll know for sure. EVERY car has soot in the exhaust, thats normal. But opti wont cause a rich condiion, only 02s and a knock sensor will do that. I wouldn't take tomuch advice from your auto teacher or mechanic.

 

My mechanic is very good and knows his stuff. He said it could be the water pump bearing or opti spark bearing. I can hear the noise also so im not sure what it is exactly. I just replaced the water pump not to long ago though(about 3-4k miles ago). I don't feel a stumble so I wonder what the bearing noise could be. I don't listen to my auto teacher because I know he doesn't know what hes talking about. He told people that I had headers on my car thats why it was so loud and hes seen it on the lift before that. My auto teacher said a scanner would only throw codes if the SES light is on, is this true? AHHH I need to figure out what that bearing noise is before something worse happens. I might just order an opti anyway because the car does have 87k miles on it.

 

An automotive stethoscope might help in isolating the noise. You could try the screwdriver to the ear trick, but it might take a real long screwdriver.

 

I have never heard of a bad opti making noise, they usally just die, throw a DTC (data trouble code) 16. When your opti dies it will die, no staggering long drawn out Hollywood, they usally dont sufer much the little guys, just maybe a week at the very most. But when they die, they go fast. Ok the bearing noise, same with water pumps, they make noise, they'll spray coolant and you'll know, once they start they go. Heres some thing thats wrong with my car. Long ago, I was in your same shoes, my car made an awful noise and people said water pump, alternator, turned out to be the a/c comp. It made this noise for 3 damn years. Still makes it.

 

Would an A/C comp only make noise under acceleration?

 

hmm thats an interesting notion, the A/C comp making noise and the knock sensor picking it up - never thought of that. My A/C comp is making noise (when its turned on and the clutch engages) and the car has some mysterious knock retard at unusual RPMs. I'll have to keep an eye on that sucker.

 

The best stethascope I have everused is a wood dowel, r the handle of a shovel. Works the best for me.

 

Opti bearings can go out. I had that happen . With the opti off and in hand I could spin the shaft and hear the same weaky-weaky noise that it was making that I couldn't seem to track down. At first I thought it was the w/p bearing going, but not. I have one of those expensive Dynaspark optis on order.

 

My car isn't running to bad, did yours when you had a screwed up bearing.