rx7raca

hey i have a question, i am not sure what it is, but whenever i start my car after about 30secs when its jus warming up, it makes almost like a whisleing noise like a leak. I think it might be a boost leak but im not sure, can someone help me figure this out.

SoCalLove

Is it more of a "hiss", "whistle", or "whine"? What part of the car is it coming from exactly?

rx7raca

ya like a high wine,but not like loud, wuts wired is that it goes away after about 30secs or so, what you think it is

rpm_pwr

ever thought of popping the hood and looking for yourself?

-pete

RTS3GEN

DOH!

rx7raca

well maybe i tired that and i dunno what the noise is so how am i supposed to even have a clue what it is. but way to help pete

R Xplicit

could be a number of things. have you had the system tested on the street? do you get proper boost? are your hoses redone, or old?
is your coolant filler cap up to par????

rx7raca

ya the car seems to be up to speed and the hoses are old,the car itself has 80,000 miles and its pretty clean, the coolet is fine, but thing is that if im pushing it, it doesnt make that noise, but maybe i cant hear it, im not sure.

Garrett

From my experience boost leaks don't "whistle", they "whoosh", "hiss", or are phonetically similar. I would stop the paranoia about the boost unless you encounter a boost problem. This will be indicated by a boost gauge. If the leak is significant enough you can usually tell by this method.

Get a boost gauge if you don't have one. However if you don't you can usually intuitively feel it through your power band.

Garrett

RTS3GEN

Does it sound like a squeaking belt? Could be your water pump going out. When you rev it does it go away or just get worse. Odds are it is the water pump going bad.
Art

rx7raca

ok thanks for the help, well once its warmed up, it sounds normal, it only happens with a cold started. it sounds like something winding up, or spoiling up. I was talking to one of my friends, and he said it might be a bearing in the first turbo, but hes not sure. I hope its not. any other info would help.

thanks

rx7raca

ok i just started my car up and tryed to listen where it was coming from, the noise came on but after about 30secs after the engine was going, it didnt happen right away and i listened and it lasted for like 10secs. then it stopped.

I gave it lil gas and it didnt hear it, for some reason it only happens in the beginning of a cold start or maybe just when its really cold out like it has been getting. As i listened i dont think it was coming from a turbo. i think its from one of the belt driven iteams, im not sure which one tho.

RTS3GEN

Probably not the turbo bearing. If the bearing was starved for oil at startup there would be a problem with the turbo spooling and boost, and if it was that noticeable you'd have more problems. Check under the water pump pulley and see the little "weep" hole on the under side of the water pump snout? check to see if it is caking up with coolant "candy". If it is dripping water/coolant or caking up, the seal is going bad and you'll need to replace the W/P. It could also be any of your other belt driven accessories and the idler pulley. It would most likely be one of these before a turbo bearing from your description.

rx7raca

ok thanks for your help

rpm_pwr

Well all I wanted you to say was "i think it's coming from <insert some general part of the engine bay>"

It has nothing to do with your turbos. Do you still have your air pump? If so disconnect that and see. If you're on the stock computer then it will begin to lope though.

-pete

FD Seeker

My car exhibits AN INCREASINGLY LOUD HISS for about 10 sec if I let the 3K RPM cold start-up do it's thing. Usually, I start it in gear or tap the gas pedal so the RPMs go down and the noise stops.

This noise started after I got my Apex intake, so I assumed it was a normal side-effect (like the moo). I was thinking that 3K RPM at startup is creating some boost which is being blown off (which is now audible because of the intake).???

twint78

aight check these out rx7race.

ur not going to have boost like at idle,so it is not this.why?ur engine is not under pressure to build boost.

if it does this when it is cold for a bit then and u r hearing a whining it is ur belts.ur waterpump going out is the craziest thing.trying to scare u.ur belts either are worn out,have a slice somewhere,or are stretched.

if it was a turbo bearing it would be more of a metal on metal contact noise,and it wouldnt just stop after it got warmed up.

replace ur belts and get back to us. thanx

Street King

Air pump, mine did that on cold nights. It's a sign it's going out and time to chunk it.

rx7raca

i know its not a belt, thats wit out a doubt. it could be a the air pump it sounds like its in that area.

RTS3GEN

AWS-is the cause for the HISS, normal, just blip the throttle and disengage the AWS....Not really a good thing for the engine anyway...If you need to know about it you can do a search on AWS.
Art

FD Seeker

I'm aware of the AWS, but that doesn't exactly explain the hiss/whoosh sound.

rx7raca

whats AWS?

FD Seeker

"All Wheel Steering"

Just kidding... it's the Accelerated Warmup, which revs the car on cold starts.

Like mentioned above, a SEARCH on AWS will tell all.

FD Seeker

..

SoCalLove

Automatic Warmup System. It's when your FD revs up to 3k rpm for about 10-15secs to warm up the cats. Slip her in 1st gear to dissengae it. Bad for the engine.