paw140

I was just on my way home tonite, and I noticed that my charging system idiot light was lit up slightly. Then I noticed that when my RPM's dropped down to idle, the light would get brighter. As I increased RPM's, the light would go out. I figured my alternator was going.

Then, a few blocks later, I noticed that the little warning lights on the oil pressure gage and temperature gage were doing the same thing. Light up at idle, then slowly fade to nothing when I increased RPMs. Then, when I got home and pulled in the garage, and noticed that my idle was kinda messed up, rough and bouncing a little, and I could here a random clicking noise from under the hood. So I popped the hood, and my air pump is what's making the clicking noise. It was clicking at random, every second or two. Everytime it clicked the idle quality would change slightly.

A little bit of background: I just installed a midpipe, and just let the air pump hose vent to atmosphere, and did not unplug or disconnect my air pump in any way. rxplicit suggested that I unplug my air pump or else I'll burn up the clutch, but I think I've probably put about 15 miles on the car since I put in the mp. I kinda doubt the midpipe install has anything to do with this problem, but who knows?

Is it possible that my alternator is going bad, and that is screwing up my airpump functions since it's not getting enough voltage at idle? I tried restarting the car, and it started fine (the battery is not dead).

I was also having a strange oil metering pump check engine light right after the mp install, putting my car into limp mode. After resetting the ECU, it hasn't come back.

I think I must have angered the Rotary Gods or something... all of these little problems all of a sudden, and seemingly unrelated. Any suggestions?

paw140

Come on guys... what are the symtoms of a bad alternator?

paw140

Bump!

wishbanzai

My car is doing a similar. But does the random clicking when not even started. Would appreciate some help anybody.

grampa

Do you have the factory service manual? It has some decent trouble shooting charts. First be sure your battery terminals are clean and make good contact. I can scan the trouble shooting chart for the alternator if needed.

R Xplicit

paul,

these were the same symptoms that i saw with my black fd when the alternator was failing...if there is a car quest down there, you can get an alternator for ~175

the clicking that you are hearing it the engaging and disengaging of the clutch drive on the air pump....

louis

paw140

$175? Good god, is that new or reman? I think I'll pull mine and take it to autozone and have it tested. Maybe this was causing my OMP code (fingers crossed).

Thanks guys. I do have the factory service manual.

R Xplicit

you know it is funny, i started throwing a CEL in my car right after looking at your other thread the other day. never has this happened before. i do not know how to check the code though, cause i have never had to....


175 is on the cheap side, from what i have found. also, for the alternator, just have a service station put a load tester on it while running, and that will tell you if the alternator is crap or not...

louis

paw140

Let's see... Autozone $230 to $285, I think they're new. Advance Autoparts $205 for a reman and $265 for new.

I'll check Car Quest. FD part prices never cease to amaze me.

paw140

Finally got your first CEL, huh? Very easy to check. There's a little diagnostic box near your battery. Take the cover off, and with a piece of wire or maybe a thin paperclip, just connect the TEN and GRD terminals. Turn on your key and the codes will flash on your check engine light.

R Xplicit

cool, thanks/

however, i thought that it was weird because the light will come on and go off at will. i am thinking a fouling o2 sensor, hell, there really isn't too much more to check....everything else is gone....

Far North RX-7

A alternator is a very simple device. Usually when they fail it is one or more diode's. Have your alternator checked and if it is bad. Look for a auto electric shop local. They should be able to rebild it in less than an hours work. Should run good as new for less than $100. New bearings, diode packs and all.

paw140

Thanks Far North, I'll definitely look into that. I just replaced an alternator on my daily beater, and it was only $75. If I can get my RX's rebuilt for $100, I'll definitely do that.

Louis: LOL, yeah you don't have much left in your engine compartment

Far North RX-7

One more thing. If your alternator is good, get your battery checked. That could also cause what you describe. As well check and clean all conections with the large primary wires coming off the batt.

grampa

FSM trouble shooting table:

jpandes

You should polish your alternator while it's off.

paw140

I checked my alternator voltage with a multimeter, and was only getting about 12.5 volts at idle, when I was supposed to be getting 14.1+. I guess my alternator is bad, so I took it out. Now I have to either find a place to rebuild it, or just spend $200+ and get a new one.

I let car run for maybe a minute or two while I tested the voltage. When I went to take out the alternator, it was so hot that I could barely touch it. I could lay my hand on the engine, coolant filler neck, etc., and they were not too hot. My alternator was REALLY hot, so I'm sure there's something wrong with it.

Far North RX-7

Alternator getting that hot could be good news. Get the battery checked first. Any shop should do that free. your battery could be shorted out.

paw140

I really don't think its my battery because its only like 6 months old, holds a charge, never went dead, etc. I'm gonna take the alternator to autozone today and have them test it just to be sure.

paw140

Just to finish off this thread, I got my alternator fixed this morning. It took them about an hour, and it only costed me $50! I was pretty happy with that. Thanks for the advice Far North, I never would have thought to have it repaired. That just saved me almost $200.

I just got done installing it and everything is back to normal. Except that damn OMP code came back and put my car in limp mode again. AAAARRRGGGHHH. I think my car hates me.

Far North RX-7

Great news Paw. Prices for new alternators is just crazy. Yours now should be good as new. Thanks for letting us know how it came out.