mechanical question.. - Tilted Forum Project Discussion Community

RetardedRascal · 08-06-2003, 03:37 PM

ok, i have a 89' Grand Prix 2.6L V6, Auto. trans. anyways it was driving fine and then i let it sit for 3 days. i was sleeping most of that 3 days so my brother might have taken it out and ran the shit out of it.... he said he didnt though. when i went to drive it again there was a loud sort of hissing noise and a quiet rattling noise coming from the engine and it didnt seem to have as much power as before, alittle trouble shifting. the exhaust used to be really loud but now its fairly quiet,that might be a different problem though, not sure. well, i found out that most of the noise was from the alternator.

Could the altenator be causing the loss of power or is there something else that might be wrong?

thanks for any help.

Sion · 08-06-2003, 04:29 PM

a bad bearing in the alternator could be causing the rattling sound that you hear. remove the alternator belt and start the car and see if the noise is gone. if it is, then the alternator is the culprit and needs to be replaced. but no, the alternator has nothing to do with power output. an alternator only supplies the electricity that runs through the car, from spark plugs to radio, etc. a car can even run without an alternator for a short while, running off battery power alone, as you will see if you attempt the diagnostic I suggested above.

the hissing noise is most likely a vacuum leak somewhere, and is also probably related to the loss of power. try to locate the source of the hissing so that the leak can be corrected. chances are that the vehicle will return to its former level of driving power once the vacuum leak has been eliminated.

as for the change in exhaust noise, who knows. get the other two problems solved first and then see how it sounds. generally though, exhaust noise tends to get louder, as the exhaust system degrades over time (or gets damaged by rough driving).

Peryn · 08-06-2003, 05:34 PM

Absolutely ... first thing ya need to check is the alternator. (or other belt driven accesories (such as air pump). If you have separate belts for each of em, try them separately. Most likey alternator though.

As for hissing, go check for vaccuum leaks. now. A tiny vacuum can make a car not start, not idle, or have no power. If you can hook it up to a smoke machine. Otherwise you can listen for it, spray some carb/choke cleaner around your vaccuum lines (i've heard that your engine will bog or rev when the cleaner gets on the leak), or simply listen for it. Look for round lines that have popped of connector, broken lines, or cracked ones. In an '89 their could be a lot of em though....so keep looking

DEI37 · 08-06-2003, 05:39 PM

I am going to bet that it is all one problem. And that would be a plugged catalytic convertor. Or at least some sort of restriction in the exhaust. Most likely a plugged cat, though.

skippy · 08-06-2003, 06:40 PM

Try this... check to see if your exhaust is plugged by some smart ass kid with a frickn potato... that happened to my brother

the hiss was the exhaust pressure build up .. or look for something that dented your exhaust system look underneath for a bent pipe.

RetardedRascal · 08-06-2003, 07:05 PM

It might just be the catalytic convertor thing... the mufflers are both pretty fucked up(thats why it was loud before), so the cat could be shitty now too

about how much would it cost for a cheap cat, muffler, and install? dont really have to tools to the work so i'll probably have to go to a muffler shop.

thanks for the help

Peryn · 08-06-2003, 08:48 PM

A few hundred will get ya a cheap new cat, installed and everything. Its not too painful as far as car repairs go.

Take a look at your muffler. chances are that it wont need replaced.

And listen around, try and isolate where teh hissing is coming from, then it will be easier to figure out what might be wrong. Too many things can make a hissing noise and kill performance. I didn't even think about exhaust. Take a look and see if ya banged up the pipe real bad from a rock or somthing, and look down the tailpipe for obstructions.

FastShark85 · 08-07-2003, 05:48 AM

If you don't mind a loud car and they don't test emissions where you live, pull the cat off, punch out its contents (there are a variety of ways to do this), and put it back on. Cheaper than new cats, and you'll probably gain some horsepower. Cats add backpressure, and too much backpressure is not a good thing.

08-06-2003, 03:37 PM	#1 (permalink)
RetardedRascal Upright Location: Indy	mechanical question.. ok, i have a 89' Grand Prix 2.6L V6, Auto. trans. anyways it was driving fine and then i let it sit for 3 days. i was sleeping most of that 3 days so my brother might have taken it out and ran the shit out of it.... he said he didnt though. when i went to drive it again there was a loud sort of hissing noise and a quiet rattling noise coming from the engine and it didnt seem to have as much power as before, alittle trouble shifting. the exhaust used to be really loud but now its fairly quiet,that might be a different problem though, not sure. well, i found out that most of the noise was from the alternator. Could the altenator be causing the loss of power or is there something else that might be wrong? thanks for any help.

08-06-2003, 04:29 PM	#2 (permalink)
Sion Dumb all over...a little ugly on the side Location: In the room where the giant fire puffer works, and the torture never stops.	a bad bearing in the alternator could be causing the rattling sound that you hear. remove the alternator belt and start the car and see if the noise is gone. if it is, then the alternator is the culprit and needs to be replaced. but no, the alternator has nothing to do with power output. an alternator only supplies the electricity that runs through the car, from spark plugs to radio, etc. a car can even run without an alternator for a short while, running off battery power alone, as you will see if you attempt the diagnostic I suggested above. the hissing noise is most likely a vacuum leak somewhere, and is also probably related to the loss of power. try to locate the source of the hissing so that the leak can be corrected. chances are that the vehicle will return to its former level of driving power once the vacuum leak has been eliminated. as for the change in exhaust noise, who knows. get the other two problems solved first and then see how it sounds. generally though, exhaust noise tends to get louder, as the exhaust system degrades over time (or gets damaged by rough driving). __________________ He's the best, of course, of all the worst. Some wrong been done, he done it first. -fz I jus' want ta thank you...falettinme...be mice elf...agin...

08-06-2003, 05:34 PM	#3 (permalink)
Peryn Junkie Location: San Diego, CA.	Absolutely ... first thing ya need to check is the alternator. (or other belt driven accesories (such as air pump). If you have separate belts for each of em, try them separately. Most likey alternator though. As for hissing, go check for vaccuum leaks. now. A tiny vacuum can make a car not start, not idle, or have no power. If you can hook it up to a smoke machine. Otherwise you can listen for it, spray some carb/choke cleaner around your vaccuum lines (i've heard that your engine will bog or rev when the cleaner gets on the leak), or simply listen for it. Look for round lines that have popped of connector, broken lines, or cracked ones. In an '89 their could be a lot of em though....so keep looking __________________ Dont cry kid, It's not your fault you suck.

08-06-2003, 05:39 PM	#4 (permalink)
DEI37 Go faster! Location: Wisconsin	I am going to bet that it is all one problem. And that would be a plugged catalytic convertor. Or at least some sort of restriction in the exhaust. Most likely a plugged cat, though. __________________ Generally speaking, if you were to get what you really deserve, you might be unpleasantly surprised.

08-06-2003, 08:48 PM	#7 (permalink)
Peryn Junkie Location: San Diego, CA.	A few hundred will get ya a cheap new cat, installed and everything. Its not too painful as far as car repairs go. Take a look at your muffler. chances are that it wont need replaced. And listen around, try and isolate where teh hissing is coming from, then it will be easier to figure out what might be wrong. Too many things can make a hissing noise and kill performance. I didn't even think about exhaust. Take a look and see if ya banged up the pipe real bad from a rock or somthing, and look down the tailpipe for obstructions. __________________ Dont cry kid, It's not your fault you suck.

08-06-2003, 06:40 PM	#5 (permalink)
skippy Banned	Try this... check to see if your exhaust is plugged by some smart ass kid with a frickn potato... that happened to my brother the hiss was the exhaust pressure build up .. or look for something that dented your exhaust system look underneath for a bent pipe.

08-06-2003, 07:05 PM	#6 (permalink)
RetardedRascal Upright Location: Indy	It might just be the catalytic convertor thing... the mufflers are both pretty fucked up(thats why it was loud before), so the cat could be shitty now too about how much would it cost for a cheap cat, muffler, and install? dont really have to tools to the work so i'll probably have to go to a muffler shop. thanks for the help

08-07-2003, 05:48 AM	#8 (permalink)
FastShark85 Psycho Location: In the garage, under the car.	If you don't mind a loud car and they don't test emissions where you live, pull the cat off, punch out its contents (there are a variety of ways to do this), and put it back on. Cheaper than new cats, and you'll probably gain some horsepower. Cats add backpressure, and too much backpressure is not a good thing.