wombatsauce

iTrader: (7)

My car is stock, but with a reflashed ECU only. Earlier this year, my car started doing this curious thing where when the temp gauge is up to normal, but the car isn't thoroughly warmed up yet. If I go WOT, as soon as the turbo reaches full boost it makes this really loud screech. I (of course) back out immediatly and it stops. When my car was at a dealer a while back, I asked the tech about it - he first asked me if I had a K&N filter (no) or CAI (no). Then he asked if I removed the snorkus (yes) and started to attribute it to that which was a little irritating. He poked around and noticed a small plastic connector on the tube coming out of the boost side of the turbo (I believe headed to the ECU's boost controller) and said I needed to get rid of it. I swapped it back to the stock piece, and now.. My car runs so much better it's rediculous. Before it had been stuttering, not feeling as fast as it should, etc but still making a lot of boost. Now with the stock piece, it makes a little less boost but pulls like a scalded ape and is smooth. I noticed the screech but it's not as loud (makes sense I guess). So.. I guess I just want to hear what you all think about that. It sounds like somehow that connector was allowing the turbo to spin too fast, or make more boost than the car can deal with. I probably won't ask Subaru to replace the turbo if it's a direct result of something I had done to my car, but needless to say - I will be leaving the stock connector on from now on.. The car is transformed. All from a teeny piece of plastic...

So is my turbo dead? What does that connector do? It seems like it allows the computer to see how much boost the turbo is making. Seems weird that it would change so much and I swear I have heard of people swapping that connector out for better performance..

-Jacob

RoadSpike

I believe you are talking about the wastegate acutator tube there is a t connector for a boost gauage if i remember right.

If the connector was faulty i don't think the wastegate would ever open properly and you'd get overboost. It is possible that you have damaged your engine but if this problem was taken care of soon enough and it was driven lightly in the times it was notice, its entirely possible that your car is ok.

The overboost if high enough should have triggered a cel and a fuel shut down, i can't remember the limit though. I would think the boost would cause a lean condition and would possibly damage rings.

You may want to check to see if you burn oil or if the car smokes a lil.

Best of luck

wombatsauce

iTrader: (7)

That's hot, just typed a long reply and hotmail ate it. Um.. This is the tube coming off the outlet side of the compressor. It does have a T in it, and this connector is on the 'other' side of the T if that makes any sense.. This is the tube that goes under the black plastic cover with two sorta plastic dzus fasteners. It didn't go bad, it was replaced when my ECU was reflashed. I thought the boost gauge connected on the manifold near the BOV?

I have never seen a CEL, the boost has never spiked per the OEM boost gauge, and it's never gone past .11 MPa. Never heard any bad noises, only thing ever was slight detonation - but after hearing someone elses at a meet, mine was pretty much non-existant, and the only time ever seemed like a naff tank of gas - this car has been very finicky about gas. Also has used a lot of it.... Never was able to get more than 250 miles to a tank (at or just below E).

The only symptoms it has ever exhibited has been loss of power, stuttering (slight - not lurching or anything) and then the turbo screech. I wish I would have put this stock connector on sooner though because it has transformed the car, it's soo much faster and smoother now.

Also, my car is undergoing an oil usage test and I am told that after (I think) 3k miles it hasn't gone down a drop. I can't check it myself as there is some Ultra High Security White-Out (tm) slathered all over my dipstick and cap.

The only other thing I noticed is that there is a little bit of oil film and road dirt on the bottom of the compressor side of the turbo, and there was a little in the connector I replaced (just film, no drips or anything). Maybe this is normal, but it says to me that somehow oil is getting to the compressor side of the turbo and possibly into the intake.. I dunno.

Thanks for the discussion and tips - I appreciate it. Damn I hope it's not messed up - I think the turbo is on the way out and I can deal with that, just don't want to mess with the engine.. I won't ask Suby to replace it if it turns out it failed because of something I had done to the car...

-Jacob

maku

iTrader: (2)

sounds as if you might have an exhaust leak of some sort; that's the only thing i can think of if your cel hasn't come yet / haven't been burning oil. are you using an aftermarket up-pipe or removed the stock up-pipe during some point in time?

wombatsauce

iTrader: (7)

Nah, all stock. It quit doing it, so I dunno now.. Hasn't done it for a while.

Oh well..

-Jacob

mmboost

iTrader: (2)

You surely have a leak... you're giving all the usual info. If you are running lest boost, the screech will be less and you just said you are running a bit less boost. Stock or not, you have (had) an exhaust leak.

The little plastic piece was a restirctor? And he just took it out? And you're saying its all stock? Sounds weird.

jason

wombatsauce

iTrader: (7)

So all of a sudden, with nothing ever unbolted - I have a leak? I doubt it. There is no other similar or concurrent exhaust leak type noises ever at all and I have had/heard plenty of exhaust leaks on various cars. Do turbo Subarus screech and make no other apparent noise when cold when they have an exhaust leak?

Except for the ECU reflash, the Eibachs, and wheels - my car is stock. Sure, those items have been altered - but to me that's for the most part a stock car. Nothing has ever been unbolted from the exhaust system. Not sure what is so weird about that.

I have heard many people replacing that connector for a larger internal-diameter connector. There were a few threads about it, the one I remember the most was on scoobymods. Something like a $.79 mod or something. I was going to do it, never did - and then when my car was reflashed, one of the guys swapped out the connector and gave me the stock piece if I wanted it. I did.

-Jacob

2Stroke

Yes, a turbo Suby will screech under boost from an exhaust leak, or an intake leak in a turbo-pressurized area. Your sounds like exhaust, but sometimes you'll have a leak that closes up under vacuum and opens under pressure. That usually happens in the Y-hose.

The expansion of the uppipe, turbo, etc. closes up some exh. leaks after warm-up.

mmboost

iTrader: (2)

Ish happens. Just the other day one of the power steering return line barrel nuts came loose on my car. No one messed with it. It just started leaking fluid and I traced it to this joint. I tightened it. Its all fixed now. I'm not saying I am 100% surely correct w/o hearing and seeing your car. But you are giving every sign of an uppipe (or in the vicinity) leak. Sometimes things just get loose. Maybe this is the 1 in 1,000 flanges that's not torqued down just right from the factory. Who knows?0 But to think that something cannot come lose because you've never touched it before is not helpful for reasoning a diagnosis.

jason