legacycentral bbs

I've noticed lately that my turbo (pretty sure) is making a very strange noise. I know it's hard to say what it sounds like but it's a BSHAW when I shift or go off throttle under boost. I can kind of hear a BSHH sound when spooling then the BSHAW when the turbo spools down. It sounds like it may be a bearing in the turbo. Any ideas? I don't think it's vacuum related as my cars power doesn't fell real off maybe slightly slower though so who knows. I poked around under the hood a little and I don't hear any leaks at idle but I don't really know what to listen for except maybe a whistling sound. Any ideas, suggestions appreciated.

The BSHAW sound sounds like the noise the stock blowoff valve makes if it's positioned where you can hear it....

Do you think maybe there's a small leak in the intake tubing somewhere?

You could try using a can of starting fluid to look for a leak. Spray around the intake tubing while the engine idles. If there's a leak, the engine will suck a little of the fluid through the leak and it'll affect the idle speed. It may take a second or two for it to take effect, and it takes a few seconds for the stuff to evaporate, so wait a few seconds between sprays.

have you taken the snorkus out? it sounds like you might be hearing intake noise then recirculation valve. you might have not noticed it before.

Vrg3- I'll try the starter fluid idea, thanks.

Brat4by4- I had my snorkus unhooked for a long time but recently removed it from the fender. Now that I think about it I kinda noticed the sound around the same time I removed it but it wasn't very loud and didn't always happen. Now it's very loud and always happens. You may be on to something though.

I'll try the starter fluid leak check that vrg3 suggested and see what I find.
Thanks

Pay close attention when you do it. Since this leak would be before the throttle, the change in the engine's running may be very subtle.

Also, make sure you're using starting fluid (the stuff used to help start cars' engines) and not starter fluid (the stuff used to start barbeque grills).

vrg3 wrote:
Also, make sure you're using starting fluid (the stuff used to help start cars' engines) and not starter fluid (the stuff used to start barbeque grills).

Ya ok, i'm not that thick headed. Jeez

Didn't mean to sound insulting. I just wanted to make sure... You never know. It's not that unreasonable to think you could use starter fluid. =)

Didja find anything?

No I know, I wasn't insulted or anything. Just Razzin'. Haven't had a chance to do it yet, I'll get a can tomorrow and try it.

starter fluid ROCKS!!!! It makes nice fireballs

hmmm, starter fluid makes big flame, big flame makes car go fast, put starter fluid in car? hahahaa like a shot of nitrous

Ok I did it and no leaks that I could tell. I sprayed the starting fluid at the intake too so I would know what to listen for in the engine. When I did it to the intake the engine would smooth out and maybe run a 100 rpm higher or so. Sprayed it every where else with no effect.

I think I may have stumbled on the culpret (spelling?) though today. Here in central PA it has been pretty cold lately and the sound was happening all the time. Today it got up to almost 80 and I didn't really notice it as much or as loud. When I took my snorkus completely out of the fender and only noticed the sound occasionaly and not very loud it was usually in the morning or at night when the air was cooler. So could it be 1- that i'm boosting harder with the cold temps and hearing the DV because of it, or 2- the cold air just makes the DV louder? I really hope it is the DV because the sound is like a bad bearing or severe shaft play or something. If it was that it wouldn't probably matter about the outside temp though would it?

vrg3- I just noticed in my previous post I called it "starter" fluid and thats why you clerified. I thought you just thought I was dumb. I think I have probably always called starting fluid, starter fluid and never noticed
it.

legacy92ej22t wrote:Ok I did it and no leaks that I could tell.

Hm, well that's good to know.

Keep in mind that you may still have a leak that only happens on boost, when the tubing is pressurized.

I think I may have stumbled on the culpret (spelling?) though today.

"culprit."

So could it be 1- that i'm boosting harder with the cold temps and hearing the DV because of it, or 2- the cold air just makes the DV louder?

Do you have a ball-and-spring manual boost controller? Those do sometimes have different characteristics at different temperatures, and may in fact boost higher. You should get a boost gauge so you can tell.

I don't really see why cold air would make the valve louder, but stranger things have happened.

I really hope it is the DV because the sound is like a bad bearing or severe shaft play or something. If it was that it wouldn't probably matter about the outside temp though would it?

Once the engine is running warm it shouldn't make a difference, but when the engine is cold all the lubricant is sludgier and all the ball bearings are slightly smaller and everything else is kind of funny.

I just noticed in my previous post I called it "starter" fluid and thats why you clerified. I thought you just thought I was dumb.

Hehehe... I never mean to make it seem like I think someone is dumb. It just never hurts to make things as clear as possible. And, even experienced people forget the little things sometimes.

I think I have probably always called starting fluid, starter fluid and never noticed it.

Yeah, I do that a lot too. It's usually no big deal, but I would really hate to accidentally have someone following my suggestion pour starter fluid all over their engine bay.

I wonder -- maybe you could disconnect and plug the vacuum line going to your dump valve. If I recall correctly that should make the valve stay shut. Then you can see if the BSHAW sound goes away or not. Be careful, though, since that's not really good for the turbocharger, so do it only once or twice and try not to have the boost too high when you do.

I have a Joe-p mbc (not installed) OBX turbo gauge 30-0-30 vac/boost
(not installed) Saab 900 ic (not installed) WRX hood scoop (not installed)
bad trend, huh? The mbc and gauge are recent purchases though.

I was thinking the problem may be boost related too. When you say to plug the diverter valve line you mean the side by the TB right? Not the resonator side. Maybe i'll try that tomorrow. So the cold air probably isn't it huh, damn, I was hoping that was it.

I know it's hard to find time, 'specially with a new baby, but it really should only take 20 minutes to install the boost gauge. The only thing is that you'll need to get a tee from an auto parts store if the kit didn't come with one.

I don't mean either of the big tubes! You shouldn't mess with those since they're hard to plug and carry lots of air. There's also a small vacuum line coming from the rear driver side of the intake manifold to the top of the DV's diaphragm (remember in the stock configuration the DV is upside-down, so in that case it's the bottom of the valve). Vacuum on this line is what opens the valve. If you remove that line and plug it the valve shouldn't open.

Actually I wouldn't recommend shutting off the bypass valve. If he IS getting shaft play, then the pulse will kill his turbine shaft. I wouldn't want that thing shattering on him. It'd be turbo member down...

Yeah, I guess you're right, Brat4by4.

Sorry, Matt... I hope you didn't go ahead and do it, or if you did, it didn't hurt your turbo.

It's ok, I didn't do it, been a little crazy today.

I have everything I need for the gauge(autometer gauge pod,
T for vac line) but the gauge came without the bulb assembly and i'm waiting on it to come. I only want to take the dash apart once. I may have to get a different pod too because I can't get the gauge to stay tight in it
(it wants to spin). I have a feeling it's going to take me more then 20 minutes to install though too.

Went on a couple errands today (it's warm out) and it wasn't really making the noise. I'm at a loss.

Ohh... you want it to look good... yeah, that could take more than 20 minutes. =)

I just stuffed my gauge in the center console in the space that was once occupied by radio and/or pocket. I wrapped it in some shop towels to make it wedge itself in place. I've since replaced the towels with some open cell foam. =)

You could run the vacuum line through the firewall at least, and put a cap on it. Then when you need the gauge as a diagnostic tool you can hook it up temporarily and ziptie it to something or something.

I guess that your experience while running errands just more evidence that it's related to temperature. Weird.

vrg3 wrote:
You could run the vacuum line through the firewall at least, and put a cap on it. Then when you need the gauge as a diagnostic tool you can hook it up temporarily and ziptie it to something or something.

.

Good idea, I think i'll do that. I'll probably rig it temporary until I get the bulb assembly and leave it hooked up so I can get my Joe-p hooked up too. I really need to get going on my i/c piping too.

Oh, by the way. I've noticed when it's cold in the morning. My turbo and bypass valve are really loud. I think there might be something to that.

Do you still hear the rattling noise? That's the only thing I'd be worried about.

I think it is the diverter valve. The sound started after removing my snorkus from the bumper on cold mornings and evenings. Then it really got loud when the temps got cold. Then it kinda went away when it got warm again. Now recently when I was setting up my MBC and was running high boost it was really loud and definitely sounded like it was probably the DV. So for now my mind is at ease. I do still hear the rattle on occasion though but it may be nothing. Thanks

Just an update. Now that I have my intercooler installed I can really hear what's going on and it is definitely the DV. Thanks for the help and suggestions.

The first thing that came to mind is the sound a turbo makes when the throttle plate is closed and the BOV isnt opening (at all or enough). The pressure goes back to the turbo, de-spinning it.