2G Whistle under heavy load (BOV?)

[Violet Crime]

My '95 TSi (stock turbo system) has recently developed a new sound under heavy boost; it's like a high pitched whistle. It's not a completely constant sound, though; it whistles for a short interval, seems to cut, and whistles, cut, ect. at a rather high frequency (~ a dozen cycles per second). As the rpm's increase, so does the pitch / speed of the whistle.

Also, I've never been one to pay much attention to my boost, but it seems low. Maxing at ~12-13 psi and immediately dropping back off to about 9 in a somewhat erratic manner.

Finally, with my brother looking under the hood, I redlined the engine. Wasn't able to find the leak, but he reported smoke during the test. Didn't know where it was coming from, but it wasn't a lot. I seem to have a mild coolant leak, so that may well be the cause, but I figured I'd report it as well, just in case.

Thanks for your time guys.

 

[delta448]

proper 2G front bumper removal

Just thought that might help alleviate some probability of "debacles".

 

[Violet Crime]

The pimp makes another appearance to make my life easier.

Thanks yet again. With any luck, it will be a while before I'm thanking your wisdom again! ^_^ b

 

[Violet Crime]

So, in order to fix the problems addressed here, I ordered a Dejon upper IC pipe, a K&N filter to replace the OEM airbox which would keep the IC pipe from fitting, and a 1g BOV.

Parts finally came today, and after 4 hours of work, it's out with the old and in with the new .

(This paragraph may have no bearing on the problem) When I went on my test drive, after the first one or two hard rev's, the TB hose slid off the upper IC pipe . Ran like ass, got it home, found and fixed the problem. Runs great again. Seems to run a tad rich (mild smell from exhaust, but it's not as though I sniff that every time I start her up).

So, when the engine is decelerating, about 3/4 of the time, around 1,500rpm, there is a whistle coming from the engine that sounds almost identical to a break squeal, just a high pitched 'eee'. When I step on the gas, there are 3-4 different air pressure sounds coming from the engine, one is obviously the turbo, one sounds like the new BOV , and presumably one from a leak I need to address. It is surprisingly loud. Also, watching the boost gauge, the boost spikes to 15 psi . I don't recall this system ever going that high before. It was only getting to about 12 with the leaks before, but I'm not sure where it's supposed to be.

Finally, after accelerating (not even WOT), when I let off the gas, there is a good-size kick of deceleration from the engine. Possibly normal, and I just need to get the clutch out in a better fashion, but it feels worrysome.

While I was doing the swaps, I found this on the ground under my car. I have NO idea what it is or what it's to. It's made of rubbery material, and as you can kinda see, the top has that curved shape on both sides of the opening. The bottom end has a rather large crack in it, but the opening is flat. Any help identifying would be great, as it might be the source of my problem (doubtfully).

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First thing tomorrow is a boost leak test.

 

[Tyknowlden]

i dont know alot about dsm's but my grand prix had the same looking thing break it was a pcv valve aka a vaccum good luck

 

[Violet Crime]

All right- quick update. As predicted, there was a substantial pressure leak between the BOV and the BOV flange. After reassembling it, I got most of the leak, but there is still a pretty decent leak coming from that connection. There was come rubbery pasty gunk on the BOV where it meets the flange; figuring that might be the culprit, I got 95% of it off (resilient stuff, this), but still with the leak.

I have a feeling the gasket is the problem. It came with the IC pipe, and even came in a bag with a Mistubishi sticker on it, so it looks legit, but it's almost like cloth, and on one side, there is like a small rubbery mound going all around the center in the shape of the outer edge.

I'm guessing the gunk I wrestled off was like RTV sealant, and that I should do the same?

 

[black_gst]

copper spray that gasket and it will seal up. be generous with the copper spray 2-3 coats

 

[Violet Crime]

Good advice- thanks! I don't mean to sound like a noob (though I am), should I spray one side of the gasket, or both, or does it matter, yadda yadda....?

 

[quiksilver20004]

Ok that bent rubber piece is a vent tube for the back of your headlight. You probably knocked it off while taking stuff in or out. All it is for is to keep water from getting into your headlight but allows a passage for moisture to exit your light when it is turned on.

You spray both sides of the gasket down with copper spray or you can always just seal it up with some RTV instead of the gasket, but it can be more of a pain to clean off if you ever take it back apart.

i dont know alot about dsm's but my grand prix had the same looking thing break it was a pcv valve aka a vaccum good luck

PCV valves are either metal or plastic and have a check ball and spring in them and either screw or push into your valve cover, so dont worry thats not your PCV valve
Sorry Tyknowlden

 

[Violet Crime]

Thank you so much, Quiksilver! Very pro!

Next annoying question; I got my car back together so I can go get the copper spray, but while putting it together, I noticed that on the turbo inlet hose, there's 2-3 small hoses that run off of the main hose on the bottom side, but one of the hoses is hanging free . I assume this hose is causing the problem felt when I back off the gas (excessive instant deceleration). Time to buy a Chiltons and Haynes (it's been that time for some time, if I'm honest), but I was wondering if you guys might have any suggestions / ideas regarding this?

Be back in *hopefully* less than an hour with some books and spray

 

[quiksilver20004]

Thank you so much, Quiksilver! Very pro!

Next annoying question; I got my car back together so I can go get the copper spray, but while putting it together, I noticed that on the turbo inlet hose, there's 2-3 small hoses that run off of the main hose on the bottom side, but one of the hoses is hanging free . I assume this hose is causing the problem felt when I back off the gas (excessive instant deceleration). Time to buy a Chiltons and Haynes (it's been that time for some time, if I'm honest), but I was wondering if you guys might have any suggestions / ideas regarding this?

Be back in *hopefully* less than an hour with some books and spray

Ok first question. Are those hoses coming out of the intake pipe? (the pipe between your filter and turbo)

Second off, Do you have your BOV recirculated back into your intake pipe? You should have a hose that runs from the dump neck on the BOV to the large pipe coming out of the side of your intake pipe.

When you build a little boost and let off the throttle, the BOV opens and dumps air, that has already been metered by the MAF, into the engine bay. (this is referred to as venting to atmosphere or an atmospheric BOV) What happens is when you dump that air from the intake system the ECU has already accounted for it and set up the fuel accordingly. So when you lose that air the ECU dumps more fuel into the cylinders than is needed and it bogs the motor way down.
Now with recirculating the BOV it dumps that air back into the intake tract inbetween the MAF and the turbo so you dont get that moment of extreme richness.(excessive fuel)

Here is a pic of a recirc tube i rigged up for temporary. It gives you an idea of what needs to happen though.

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[Violet Crime]

Yeah- they're off of the hose that connects the MAF to the BOV and turbo. Under the hose there are two small hoses running toward the back of the car, and one coming out toward the front. The one coming toward the front is not attached to anything.

BOV is recirculated.

Oddly enough, when I went to get the copper spray, I went WOT a few times. After a couple times, the TB hose slid off the upper IC pipe again (GodDAMN that pipe is slippery!!), tightened that down as far as I really could, and after a couple more go's, the IC pipe slid off of the IC!!! Didn't realize what had happened until I got home and started tearing away again, so I drove it light the rest of the way home.

I've applied the copper spray to the BOV gasket and flange pretty heavily and reassembled it, I'm waiting for the engine to cool down so I can get my leak tester on w/o burning myself. Should only be a few more minutes until I can bear it. Sadly, I wasn't thinking very clearly and applied one coat of the copper spray to the BOV surface, hitting the piston pretty decently. I realized how stupid I was and tried to get the gunk off, but it's pretty tacky. Looks like it's not forming a seal inside, so it should be good, but I thought I should mention it.

EDIT: Forgot to mention; whatever was causing the rude decel when I let off the gas last night seems to be gone today!! Don't know how I managed that, but I'm sure as hell not complaining.

EDIT 2: How long should I let the copper spray dry? I just did the leak test and it's still leaking! It was forming quite a few bubbles with the copper stuff, too.

 

[quiksilver20004]

I usually let it set for a minute or so but i have only really used it on exhaust gaskets and flanges. IF the copper spray isn't working then pull it back apart clean all the surfaces well and prep it all with alcohol. Then run a small bead of RTV around the flange and spread it out with a clean finger. Make sure the RTV connects all the way around and make sure you don't glob it on because when you tighten it down it will seep out the edges. So once you spread it out put your BOV back on and tighten it down. You can let the RTV cure by the specs on the tube, but i usually just put everything together and rock it!!

 

[black_gst]

is the bolt flange for the bov warped?

 

[Violet Crime]

I know, I know; no such thing as too much boost

Couple months ago, my 2g BOV started leaking, so I bought a new upper IC pipe with a 1g flange. Got it all hooked up with a friend's old 1g BOV, and it's back to good.

The thing is that ever since the swap, my boost gauge is all over the place. Depending on the particular acceleration phase, boost may top out anywhere between 15 and 18 psi (rare that it hits 18). I love my car, I don't want to run it THAT hard, but I don't want to ####yfoot 100% of the time. How do I ensure boost won't rise about 15 psi?

Yes, I'm still pretty new to all this performance stuff, so I don't even know if a MBC would be able to address this situation?

Another quickish question; when I went to perform a boost leak test, it seemed there was a fair bit of oil on the rubber o-ring-ish thing on the turbo inlet (fills the gap between the inlet hose and the metal part of the turbo [stock 2g]). There was about 1-2 drops puddled up on the bottom (lowest point on the ring), and the entire inside seemed coated; moreso than I would think is healthy, but I don't know? I know there's supposed to be some, and I'm likely just being paranoid, but would appreciate some experienced input.

Thanks in advance, guys!

 

[Gasolinebaptism]

Don't worry about the oil.
now by the sounds of it, you're running a stock turbo, with a 1g BOV and a UICP.
So the safety feature the car was built with to keep it below 15 PSI are still in place.
It sounds like your aftermarket boost gauge is old and needs replaced. because I believe at 18 PSI you WILL hit fuel cut. Fuel cut is when the car sees too much air going into the engine, knows that the fuel system wouldn't be able to keep up, meaning it will be lean combustion, and so to stop that, and get rid of the possibility of knock, the ECU cuts signal to the injectors. It's seriously like hitting a brick wall. (first time it happened to me I looked in my rearview for the tranny. It's that bad)
So considering the fact that you havn't hit fuel cut, it sounds like a bad gauge. (their accuracy isn't infinite)
Also, if you search the forum, there are posts of how to measure O2 sensor voltage, this will tell you how rich or lean it's running.

 

[Violet Crime]

Great response- Thanks a bunch!

 

[Killa_dsm]

I know, I know; no such thing as too much boost

Actually if your not tuned and don't have proper supporting mods too much boost can be bad.

Couple months ago, my 2g BOV started leaking, so I bought a new upper IC pipe with a 1g flange. Got it all hooked up with a friend's old 1g BOV, and it's back to good.

They leak stock, so good thing you changed it out.

But just to make sure do you have a aftermarket boost gauge? Your profile doesn't say you do. If you do and your hitting 18psi without any other mods, thats a bad idea. Are all your vacuum lines from the turbo to the stock bcs connected properly?

 

[haswesley]

You also asked about the oil pooling on the rubber coupler hooking your intake to your turbo. That's normal. You have a hose connecting the valve cover to your intake. That hose allows some oil to be sucked into your intake from the valve cover. Too much oil can be a problem when the oil burns in the turbo and causes carbon to build up in the turbo. But, 1-2 drops isn't a lot.

 

[eclipse gsx]

hey i adrees fuel cut ass hitting a brick wall hahahahaha we think the same

 

[Gasolinebaptism]

hey i adrees fuel cut ass hitting a brick wall hahahahaha we think the same

Yea man, I just recently got my car running after 7 years. Maybe it was the new ECU, or maybe something just was giving out a bad signal I don't know, but for the first few days it hit fuel cut at about 4500 RPM, and it scared the SHIT out of me. haha.

 

[91talonawdtsi]

Thats funny because i just got mine running after about three years too and am hitting fuel cut at 4500 but just in third gear. for some reason my bcs is letting the car run over fifteen pounds of boost.

 

[Friend-O]

Pick up a catch can to fix your oil problem, they're cheap on ebay! One of the few ok ebay products