REP/HISSING NOISE ISSUES....

[jessika1027]

Hi to all, and thanks for any help i get.
i have been struggling with a REP demon for the last 2 months and its been a very intermitant problem.

during the winter i let my car warm for about 15 mins while i get ready for work, and one morning i get in it and the infamous REP was on and i had no power(just as i have read in the searchs that others have experienced, but not found any help for my situation) i left the car for the day and when i got home that night, cranked it up and the light was off and running fine.

.... a month goes by and it does it again, exactly the same. i have had it scanned and nothing is coming up except the o2 code cause i dont have a cat on my car.

ive been driving it daily since the 2nd time it happened and its been fine, until this morning...

now, i have a sqealing noise that is almost a vaccum leak sound, it only happens when its cold and varies with revs of the engine. it totally goes away when in drive or reverse....

i have 62k on the car and ive had it for 2 years. i was just thinkin the other day what a great car its been...did i jinx myself?

any help or insite is soooo awesome, cause i love my car and the only local awnser ive gotten is... get a new car UGH!!

thanks once again,

Jessika

[Rob Bell]

Geez, whoever's telling you to get a new car sure sounds like a lot of help. If you think it may be vacuum, I'd get a vacuum gauge and hook it up to see if it's really the problem. The worse thing you have to take it to the dealer for a diagnosis.

Listen around under the hood too, and see if you can pinpouint where the sound is coming from. You can take a piece of hose, and use it like a stethoscope.

[jessika1027]

thanks for the ever so quick response. this may sound dumb, but where would i hook a vacuum gauge to? im pretty good with the basics but not the best at diagnosing. any clue with my random REP?

[jessika1027]

I SHOULD ADD... i think another good way to describe the noise, is "blower like"
if that helps any

[Turbo V6 Camaro]

what do you mean bye "REP" ???

if its a wining sound check out the alt they like to wine before they go

[Rob Bell]

I'm assuming REP = Reduced Engine Power

Yes if it's a "blower-like" whine, that could very well be the alternator. And on newer cars with computer controls everywhere, a faulty alternator can cause all kinds of strange problems. Using that hose can help you see if the whine is coming from the alternator.

As for the vacuum, I have never checked mine, so I am not sure exactly where they are. Others on the board can tell you that, or do a search, especially in Forced Induction, they are always working with the vacuum lines to hook up their FMU's. But pretty much any hose that attaches to the intake is a good candidate for a vacuum line. Just hook the guage to the end of the line that is not attached to the intake, and see if you get a vacuum reading at idle. I think it's supposed to be around 22 inches Hg or so. But again, there are lots of people on here that can tell you exactly where you should be looking.

Another REP possibility could be your throttle body. Because it's drive by wire, if any little thing appears strange to the computer, it's going to go into REP for safety. You could check the connections and make sure they are tight with no corrosion.

Good luck. [img]redface.gif[/img] )

[jessika1027]

thanks for the thoughts... one question what is "drive by wire"

[Rob Bell]

On the 3.8L V6, there is no throttle cable. The throttle body is controlled by the computer.

[jessika1027]

If i did in fact have an alt that was going...and possibly caused the rep to come on and go off, wouldnt the alt gauge show something? ive always thought my alt registered high but its been this way for at least the 2 years ive had it

[Turbo V6 Camaro]

Originally posted by Rob Bell:
On the 3.8L V6, there is no throttle cable. The throttle body is controlled by the computer.

only in 2000 and up cars [img]smile.gif[/img]

[jessika1027]

OK now im lost, so i know i dont have a throttle cable.... so im not driven by wire..?

does anyone know of a way to set the REP, like flooding the car out or something like that...i dunno if it was a fluke that happened twice or if someone is messin with my car.

since last week it seems my gas mileage is waaaaay down....

[camaroincal]

Maybe trying resetting the cars computer by unplugging the negative (black) battery cable overnight. Worth a try. Also, you have an SES light on? If so take it to Autozone for a free scan.

[jessika1027]

The light has only come on twice, and after sitting all day it was off when i restarted the car, the SES light is also on because i dont have a cat, and i just learned about the sim's and i dont have one yet. It has been scanned with a snap on scan tool and shows no other codes except the 02 sensor one

[Rob Bell]

Viper's right, drive by wire is only on 2000 and up. I assume that you're talking about the 2002 convertible in your sig?

I would think that a bad alternator would be seen in the gauge, but you never know. It could be putting out the right voltage, but maybe the amps are not enough, or the output has noise in it that messes with the computer. That's something that you'd need an oscilloscope to see.

If gas mileage is down then you need to check stuff like plugs, wires, fuel pressure, fuel filter. Basically fuel and ignition stuff. With 62K on it, it may be ready for some of that stuff. But I wouldn't think that would cause a REP mode. That stuff seems to cause misfires and sets codes that would be scannable.

I have no idea how to force it into REP. If it's very intermittent, and it's not setting a code, it's going to be very hard to diagnose. Do you get a check gauges light in addition to the REP? I know for a fact (per the owner's manual) that if the computer thinks the car is overheating, it will go into REP. If it thinks the oil pressure is too low, it may do it too. I'm sure there are other circumstances that will set REP. That's where a scanning software comes in handy.

Short of getting scanning software like Auto Tap or Hp Tuners, you may need to take it in to a dealer to have it looked at. They may not even find anything if it cannot be duplicated. Sometimes you have to let an annoying problem just get worse until it can be duplicated. Then it can be diagnosed and fixed.

[Rob Bell]

Camroincal has a good idea, try resetting the computer. If you have the stock radio, make sure you know the security code for the radio before you cut power though.