Well, I've been having charging/battery problems for as long as I can remember. As of right now I have a new Delco stock alternator and an optima red top battery.
If my car sits for more than a day or so the battery is dead.
I tried unplugging my stereo (thats the only thing I've added that draws power from the car back there) to no avail.

Tonight, I was working on the car.. It hasn't been running for 3 or 4 hours. I was working in the hatch and heard an EXTREMELY strange noise. The stereo's fuse was pulled so I know it was not an amp/speaker.
The noise is very hard to describe... it sounds like a moose or a cow... or kind of a horn/nose blowing noise.
It's very distinct.
This isn't the first time I've heard this...
Does anyone have ANY idea what it could be??
Would a dying fuel pump make that kinda noise??
What about my power hatch motor??
Those are the only things I can think of that uses power from the rear fo the car.

Again...

#1 It's coming from the REAR of the car
#2 It's a cow/horn/nose blowing sound
#3 It's a motorized sound (you can tell its something electrical)



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1988 red Iroc-Z, 57k miles, stock tpi, zz4, 2.77 4wd, probuilt stage 3 700r4, 2800 vigilante TC, TES headers, dynomax 3" catback, nitto DR, ported plenum, afpr, free mods.AIM: IrocZzach

12.96 @ 106mph 1.9 60ft

 

Well zachy, my advice is when you hear the cow sound (lol) start pulling the fuses one at a time till it stops. If you get all the fuses out and it's still buzzing, then it might be your fuel pump. I think the fuel pump's fuze is NOT in the fusebox, it's somewhere else.

 

Well, i dont know if this will help or not. But on my old GTA, it used to do that almost every time I parked the car. Would go on and off all night. Then by the next morning, the car would barely start. I traced the problem to a faulty fuel pump relay. Dont ask me know it was doing that, but it was. Replaced the relay, and problem solved. Anyway, id look at fuel pump/related items. Later.

 

it only lasts a few seconds...
long enough for you to go... WHAT THE HELL IS THAT??

then it stops...

Anyone know approx how much a FP relay is?

 

zachy, i think it's just the fact that your IROC SUCKS! :evil: So...when do i get to ride in it again?

Sounds fuel-related to me.

 

the noise you are hearing-best guess,but i know im going to be correct-is the fuel pump running.here is what is happening, the oil pressure switch is supplying power thru its contacts even after the ignition switch is off until the oil pressure bleeds down internally to (i think)4 psi and the contacts open within the switch and it cuts power to the pump. its a normal thing that gm designed into most all fuel injected cars-no oil pressure=no electricity to fuel pump=no start. it is a safety thing.most dont get it that even if the fuel pump relay fails, your car it still going to start and run. the cranking time will be extended because the oil pressure needs to build up to close the switch but it will run. i think on your year it is still separate from the oil pressure sender for the gauge. but it is a normal thing to happen, but the fuel pump may be getting louder and that should be checked out if it is getting old with many miles on it.

 

The car does still start and run, thanks for explaining that though if my battery problem isn't fixed after the FP relay.

Is there anyway for me to test if theres a SMALL drain on my battery when the car is off? (multi meter etc)

 

check your rear hatch pulldown motor, My 86 T-A had the same problem killing batteries and I found the hatch pulldown motor was jammed and constantly pulling power. there is a relay in the rear under the back trim panel, try unplugging that and see if it still happens ????

 

https://www.thirdgen.org/techbb2/sho...threadid=77039

 

I was going to suggest the same thing.

 

My vote goes for the fuel pump relay. When mine went bad, it woulnd't always shut the fuel pump off when the car was shut off. In fact, I went out to get in the car one morning and the fuel pump relay had run all night. I was lucky that it didn't kill my battery, or it would have been much harder to find.

Remember, the fuel pump relay ensures that the fuel pump runs anytime there is oil pressure. Therefore, a faulty oil pressure sender could also cause this problem.

If it cost $10, I'd be surprise. I do remember that it was cheap and a 5 minute job.

 

not exactly-the ecm will close the contacts in the f.p.relay initially for about 2 seconds when the key is turned on but will not close them again until a tach signal is picked up by the ecm. you can actually disconnect the relay when the motor is running and it is not going to stall, if the oil press. switch is ok. a bad relay (failed open) will cause extended cranking till oil press. is spun up via the starter. the oil pressure switch supplies power anytime there is oil pressure. look, here is a way to see- get to the aldl connector under the dash-find terminal g and hook up a test light to it (pointy end)put the other end of the light to ground.with the car running ck for power at the terminal-then turn off the car and you will see the light stay on along with the pump for a second or 2 if this co-incides with your noise-you got it figgered out also if the oil switch and sender are one on your car-list on a delco replacement is right around 50 bux. if the switch and sender are separate the costs are less. seeya

 

Here is my experience. My rear hatch otor never really worked so I pulled the connection, but then my friend gave me a gear for it from a Caddilac. Worked fine for a few times, but then it split in half. Because it never reached it's trigger point the motor would run on and on!!! My idiot mechanic buddy said it was the fuel pump pressurizing the line. When it was off?!?! I dont think so.

So you may have stripped the teeth off your gear, or split it. It is a buzzing noise, not a squel, almost like a vacuum cleaner.

 

oh you mean to say i made the up? wow aint you something. carry on

 

My 89 RS does it too. Moooooooooooooo. If i open the gas cap it goes PSSSSSSSSSSSssssssss...... no more pressure, no more mooing. whenever i go anywhere now i let the pressure out of the tank so it doesnt moooo. I have no clue what causes it....

 

Re: the battery dying after a day, I once had a car that did that and found out one night it was the light under the hood staying on all the time.
There's my .02

 

I didn't even read your post. This was just my experience; nothing to do with you. My dumb mecanic thought that the car was going to blow up, and freaked out my mother. Now I have to store it with the battery disconnected.

And I really am something! Thanks for the pick me up.

 

My 89 Grand Marquis does the same thing yours does, though my sound isn't a mooo its more a hiss. But its definitely the fuel pump on my car. It does it more often when its cold out. I havve to disconnect the batt most every night so the batts not dead the next morning. Hopefully its just a relay.

Good luck
Chris

 

I cant remeber what cause the problem , but i know how he fixed it.

It's a very destinct sound, kinda like whales humping or something.
It's not the fuel pump relay.
It's not the fuel pump.
It has to do something w/ the tank.
There is a canister type thing that has to do with releasing or filtering out gas fumes. nyways there wasnt any actual fuel going into it. So we just cut it out and plugged the line w/a screw. Fixed the problem. yeah it was funny though. First time it happened we were at a party and we turn of the car, and it lasted for about a goood 10 secs. it was pretty embarrising. I think it has something to do with vapor lock or releasing vacum from the gas tank.

hope that helps
bowtieguy01

 

You know it could be the hatch. Maybe something is holding that thing in place untill whatever happens it releases then moves the motor down. See of that hatch motor is getting hot because that was what was killing my battery. The Damn hatch motor never shut of, it just kept on pulling down. Still haven't fixex that pos.

 

What BowTie may be talking about is the tank pressure control valve and surge valve in the filler cap. As the tank cools, air is drawn into the tank via the surge valve.

As for your moaning noise, make sure none of your buddies are getting busy in the back seat, and don't overlook the power antenna motor.

 

Are you serious, the only hump is between the seats.
Besides it's hard enough just sitting back there.

 

tank pressure control valve-loosen the fuel filler cap next time and see if the symptom disappears.

 

Open the hatch and hit the switch that raises/lowers the hatch motor and see if that works properly. I'm willing to bet it's the hatch motor.

 

That should be the only electric motor running after hours. Probably a broken gear, like mine, or a faulty sensor. Dont take it to GM; they will just bolt up a $150 new unit.

 

i thought the fuel pump stopped working like 30 min after engine shutoff for sure

 

Not even that. More like a few seconds.