Odd noise when boosting

[Corpssnare]

I'm not sure how common of a problem this is as I've been spending the past hour or so filtering through posts trying to find a similar problem, but I haven't found anything yet.

When I start my car when it's cold, I'm getting the classic starter grind I've found most 2G DSMs get. What concerns me is after I start driving, I'm getting a similar sound when I'm boosting through the first couple gears, and it'll do it after ANY boost, even like 4psi. It just gets louder as I boost it more. It only does it right after I start driving, and it'll stop after about 3 gears worth of light boosting (1/2 throttle or less). After that, it won't do it until I shut the car off again. It doesn't really seem to matter whether or not the car is warmed up or not, but letting the car idle a few minutes seems to make it go away more quickly. If it's still warmed up (ie I shut the car off after driving it for a while and start it again a short while later), it'll start that grinding sound again, but maybe for only the first gear or two. It's been doing this for about the past year, so I don't think it's a very serious problem, but it's just annoying. I've checked the belts and oil and those are all fine, I'm not really sure where else to look just yet, so any help from a more experienced DSM'er would be greatly appreciated.

My car is pretty much stock, minus a couple free mods (hacked airbox and a pulled boost control solenoid).

 

[kenamond]

My first thought was that your turbo is rubbing the housing, but I'd be suprised if it lasted a year like that. Nevertheless, I recommend checking the turbo for shaft play. Pull the intake pipe off the compressor inlet (let motor cool first) and try pulling the compressor wheel in/out of the housing and up/down or side/side. Also check if it spins freely. If you have excessive side/side/up/down play (hits the housing) or any in/out shaft play, the turbo may be the cause and may be close to death.

When mine started to fail, it would chirp and wail and howl under boost. But it only lasted that way for a few days before the turbo pooped out.

If the turbo does fail, it can pump massive amounts of oil out of the engine and into the intake and exhaust, so you should immediately park it if that happens (you'll see a huge smoke screen in the rear-view mirror). My car dumped over a quart of oil into the intercooler in under a minute when the turbo went.

Or maybe it's something completely different.

 

[97redgsx]

im not familar with this starter grind, but it doesn't sound like a good thing... how loud is it? is it possible that what your hearing is lifter tick? have you popped the hood and listened for it? as already stated i would definatly check the turbo out, but if thats fine i would also look at your starter...the solenoid could be shorting itself or something, maybe the contact disc is getting stuck...it is hard to diagnose "noises" over the internet but maybe you could make a lil vid?

 

[kenamond]

im not familar with this starter grind, but it doesn't sound like a good thing... how loud is it? is it possible that what your hearing is lifter tick? have you popped the hood and listened for it? as already stated i would definatly check the turbo out, but if thats fine i would also look at your starter...the solenoid could be shorting itself or something, maybe the contact disc is getting stuck...it is hard to diagnose "noises" over the internet but maybe you could make a lil vid?

The starter grind noise (if it's like mine) is almost like a belt squeal but not that high pitched. It's a high-pitched grind right after you start the car. Mine did it since it was new. I went in to one of the Chrysler "schmooze the new customer" meetings a month or so after I got the car and asked about it. A couple other new owners mentioned that they had the same problem. 83k on the stock starter, so it doesn't seem to hurt anything. But the point is that it's high-pitched and sounds kinda like my T25 did when it was on its way out.

 

[c4uldr0n]

This may or may not be unrelated, but I had similar problems when the check valve failed going to my brake booster and would cause the diaphram in my brake booster to make some odd noises.