High pitch noise
 

Hey all.

I've just become the proud owner of an '04 WRX PPP with 23,000 miles on. I have done a lot of searching the past few days, but none of the threads seem to be describing exactly what I am experiencing.

There is a high pitch noise, sort of like air escaping, which seems to be coming from the engine bay on the passenger side. I notice it mainly around 70mph, though it is there at other speeds, and varies as my speed does. I can hear it in 4th and 5th gears, and the pitch is the same no matter which gear I'm in as long as the speed is constant. It is there if I'm accelerating, or just holding a constant speed, but it stops if I take my foot of the accelerator completely.

Edit: Forgot to mention, it's not a loud noise, and can only be heard with the stereo off.

All input appreciated
Neil

Hi and welcome,

Not had this on a scoob but on a Landcruiser - used to make a high pitched sound like a worn wheel bearing/whining at between 80-100mph above or below those speeds it was non-existent.




It was the wing mirror!

Thanks for the welcome mate :)

After reading some of the threads, I thought it may be the wing mirror, but it stops as soon as you lift off the throttle, so I'm guessing it must be engine related. I wondered if it could be a boost leak, but it does it when I'm travelling at a constant speed and it shouldn't be boosting, and the car pulls extremely well :)

I have noticed a "very" slight flat spot around the 3k revs mark sometimes when accelerating from very low revs, but I doubt it's connected, besides, the official dyno for the ppp shows a slight drop in torque at around 3.5k, increasing again around 5k ish.

I also forgot to mention, it's not the aircon unit, though mine is slightly noisy, I've gotten used to that now :)

hi n welcome to u mate.:) the best thing to do is check that all the hoses that r connected to your intercooler r on properly n tight it might b worth it if u check that the pipe beneath the intercooler the y pipe is on properly but to do this u have to take off your cooler and also hav a look at where your dumpvalve is make sure thats on proper 2 also have a look to c if u have a broken or lose gasket there :thumb:

Thanks for the suggestions mate :)

I'll have a look over the parts you've mentioned over the weekend.

BTW...Could the slight loss of power I sometimes experience be due to mild overboost?

Cheers
Neil

I've booked the car into the dealers, as I decided it best I didn't go messing around under the bonnet :)

They're going to check all the pipes, dump valve etc. I've also asked them to have a look at the MAF. Is there anything else they should be looking at...plugs or coil packs?

I asked if the slight dip in power could be due to overboost, and they said that if it was overboosting, it would be like hitting a brick wall...is this true?

Lastly, could the dip in power be a "flatspot", or would it do it every time if it was?

Cheers
Neil

Good idea mate no point messin with ya car,i dunno about the overboosting but the dealer should sort it all out for u:) has ya car been all sorted now

My spam filter must've ate my notification email :)

The dealer dismantled all the intercooler and turbo pipes, and put it all back together again. They also checked for fault codes, of which there were none. The DV (or whatever it is) was checked over. The noise is still there, so they have concluded that it's normal.

The car's running great, but I do still sometimes feel that I get full-power, then it slightly dips, then comes back in. The dealer maintains that overboost, however mild, would result in fuel being cut, but I don't know about that. It seems to happen when I put my foot hard down, but if I gradually apply throttle, it seems ok.

I think it may just be a characteristic of the car. I would like to get hold of a boost gauge to see if it is overboosting, but I doubt there's anything I can do if it is anyway :)

Cheers
Neil