OEM Blow off Valve Problem?

['95EclipseGSX]

My 1995 Eclipse has 211,000 miles on it. It's 100% stock. A few thousand miles after I rebuilt it (1.5 years ago, 196,000 miles) the turbo started making a different sound. Instead of getting the standard turbo whistle as it builds boost it will start to make a more windy noise (Similar to the sound your mouth makes if you have your tongue touching the roof of your mouth and you blow out, for lack of a better reference.). This happens when I build boost fast. When the boost hits the top half of the gauge (stock gauge) is when the noise starts to happen.

I've read about maybe the blow off spring just being tired and not being able to stay closed at boost. My car doesn't feel like it has any less power but I guess there could be a marginal difference. I want to fix the noise because I feel it takes away from the excitement of the turbo as it is under boost. I am wondering if you guys think it could be the blow off valve or if it is something more serious. Just from the sound description I gave. It would be awesome if I could fix it by replacing the blow off valve.

Thanks!

 

[clipto]

I would recommend getting a boost gauge,hard upper intercooler pipe, with a 1g or aftermarket bov the stock 2g one is horrable. You could also get a fmic from VR Speed Factory - Discount Import Performance Parts is at a good price. Check boost leaks and check shaft play in the turbo, it could be a bad turbo. Doing a turbo swap is always fun with a 14b or 16g, but that gets you started on another story. Oh and don't forget to do your maintenance!

 

[idoceclipse]

About a year ago mine started making a noise like what you are describing. Kind of like a supercharger. I just kept on driving it till about 2 weeks ago when the turbo was completely blown. I suggest do a boost leak test, fix any leaks you might have and see if that changes anything.

 

[agarc023]

I would recommend getting a boost gauge,hard upper intercooler pipe, with a 1g or aftermarket bov the stock 2g one is horrable. You could also get a fmic from VR Speed Factory - Discount Import Performance Parts is at a good price. Check boost leaks and check shaft play in the turbo, it could be a bad turbo. Doing a turbo swap is always fun with a 14b or 16g, but that gets you started on another story. Oh and don't forget to do your maintenance!

At this point a front mount intercooler would only hinder the op's performance.

 

['95EclipseGSX]

Haha well I appreciate all the suggestions of upgrades but I am really looking to solve this problem with as little cost and time as possible. How do I check for boost leak? How do I check to see if the BOV is working correctly or if the turbo is working correctly? I have no idea what I'm doing...

 

[agarc023]

First off a search will get you all those answers.

For a boost leak test you need a source of compressed air and a way to get it into the turbo's inlet (all this after removing the intake pipe and filter). You can build a tester pretty cheaply from parts you can find locally.

To check the turbo grab on to the nut on the end of the shaft and try to wiggle it. A little side to side play is okay. If it moves in an out then start looking for a replacement turbo.

As far as the bov goes it will most likely let air out during your boost leak test. It shouldn't, but as stated it's a weak point. You can try to mod it like a 1g bov but it's not too common to stick with the stocker anyways. An evo 9 (if I remember correctly) bov will be a direct fit and will hold boost a lot better. It is a little more costly though unless you can score one for cheap.

 

['95EclipseGSX]

I tried searching but couldn't find any directions that were explicit enough to make me feel comfortable to do a boost leak test. They all just say "soapy water" and then trail off haha...

agarc023, you said that the Evo 9 BOV holds more boost, does that mean that simply by replacing the BOV my car will have more horsepower than stock? I thought the car's computer was set to let off pressure at a certain point meaning that unless I change that a better BOV won't do anything different. I am sorry if these are silly questions but I don't know much about the turbo system. If there are some resources I'm missing I'd love to check them out.

 

[9!'clipseDOHC]

I tried searching but couldn't find any directions that were explicit enough to make me feel comfortable to do a boost leak test. They all just say "soapy water" and then trail off haha...

agarc023, you said that the Evo 9 BOV holds more boost, does that mean that simply by replacing the BOV my car will have more horsepower than stock? I thought the car's computer was set to let off pressure at a certain point meaning that unless I change that a better BOV won't do anything different. I am sorry if these are silly questions but I don't know much about the turbo system. If there are some resources I'm missing I'd love to check them out.

Here is how to do a boost leak test: http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/169435-boost-leak-test-how-boostpro-net-tester.html

Here is how to make a boost leak tester: http://www.dsmtuners.com/forums/articles-parts-fabrication/386650-how-build-boost-leak-tester.html

If your stock BOV is leaking (which is common), then yes, you will be making less horsepower then stock and a new/different style BOV will give you more horsepower then you currently have.

I agree with agarc023, do a boost leak test and check the turbo for shaft paly (by removing the intake pipe and moving the shaft inside the turbo. Check for side to side play and in and out play).

Hope this helps!

 

[miguelmcv]

(9!'clipseDOHC ) Insert a good rite up.

Fallow that rite up.

Take off the Blow Off Valve when doing the leak test, Check if that is leaking, If it leaks, then replace it.

Before you install the leak test coupler, Grab the Nut (inside the turbo) and try to move it up and down and Inside out, If it has to much play, then it might be bad (It doesn't have to have to much play.

 

['95EclipseGSX]

Thanks 9!'clipseDOHC that was extremely helpful. What kind of blow off valve would you recommend I replace it with? I have found stock ones for around $100. It did work for 15 years so maybe I should just get another one. My plan is to order a BOV, when it comes pull the old one off, check the turbo for shaft play and if there is little/none, install the new BOV. Then start car and step on accelerator with fingers crossed, hoping problem is resolved.

 

[miguelmcv]

Fingers X for you bro.

 

[9!'clipseDOHC]

Thanks 9!'clipseDOHC that was extremely helpful. What kind of blow off valve would you recommend I replace it with? I have found stock ones for around $100. It did work for 15 years so maybe I should just get another one. My plan is to order a BOV, when it comes pull the old one off, check the turbo for shaft play and if there is little/none, install the new BOV. Then start car and step on accelerator with fingers crossed, hoping problem is resolved.

First, I would verify that your BOV is the problem (although it is a good chance). I wouldn't replace it with another 2g BOV though as they were poorly designed from the factory. I would go with, in this order:

• EVO 9 MR (metal, bolt on)
• EVO 8 (plastic, bolt on)
• 1G DSM (Metal, requires adapter)

You can get any of those used for pretty cheap, or you can get the EVO 9 MR brand new for $160 from STM.

Check out this thread for more info: http://www.dsmtuners.com/forums/newbie-forum/242821-stock-bov.html

On 2G stock BOV you will hit about 14psi, then leak to 11-12psi, and hold steady. The easiest, and cheapest BOV upgrades would be a metal 1G BOV (22-23psi), stock plastic EVO 8 BOV (21-22psi), stock metal EVO 9 BOV (22-23psi). All can be got pretty cheap, look on out classifieds for 1G part outs, or look on EVO forums for parts being replaced on EVOs.

Dustin

My original statement in this thread is correct, the EVO 8s are plastic but the can hold more boost then the 2Gs, but they can crack, the evo 9s, and 1Gs are metal, the 1G BOV will be the easiest to come by since kids are parting out 1Gs like crazy If your not planning on boosting past 22psi or so the stock 1G will work great, if you plan on boosting past that then you could crush it 1/8", or do the dodge garage mod to it, so it can hold a bit more, people have used these BOVs on cars boosting up to 30psi, if you ever boost past that you might as well just get a Tial 50mm.

Dustin

 

['95EclipseGSX]

Cool! OK. I'm going to get the Evo 9 I think. Just a few last questions: Will it damage my turbo or any engine components by getting a BOV that boosts an extra 8 PSI? Or do I need to adjust it to blow off at 14 PSI? Do I need any other gaskets or anything besides what the BOV you linked me comes with? Thanks so much 9!'clipseDOHC for the help.

 

[9!'clipseDOHC]

Cool! OK. I'm going to get the Evo 9 I think. Just a few last questions: Will it damage my turbo or any engine components by getting a BOV that boosts an extra 8 PSI? Or do I need to adjust it to blow off at 14 PSI? Do I need any other gaskets or anything besides what the BOV you linked me comes with? Thanks so much 9!'clipseDOHC for the help.

The BOV won't raise you boost level above stock (it may raise it back up to stock if yours is indeed leaking though). The Boost Control Solenoid and the Wastegate are what regulate the boost levels. The BOV's job is to when the throttle plate closes to release the boost (pressurized air) from the intake track.

You shouldn't need anything to install it in the stock UICP (upper intercooler pipe). Just a screwdriver to work the hose clamps.

You are very welcome!

 

['95EclipseGSX]

Ah man, if the BOV is all it is this is gunna be a walk in the park!! Can't wait 'till the BOV comes. I hope it sounds sexy.

 

[9!'clipseDOHC]

Ah man, if the BOV is all it is this is gunna be a walk in the park!! Can't wait 'till the BOV comes. I hope it sounds sexy.

That's why you should do the boost leak test... to see if it is the BOV that is leaking.

 

[Boostinsideways]

Ah man, if the BOV is all it is this is gunna be a walk in the park!! Can't wait 'till the BOV comes. I hope it sounds sexy.

Pretty much exactly the same as yours, a bit stiffer though. Not as prone to leaking.

 

['95EclipseGSX]

Damn it wasn't the BOV. Oh well, glad I tried. Now I have nothing to do but a boost leak test. If I ever get around to it; it seems very intimidating. 9!'clipseDOHC, the instructions you linked don't really explain what seals/hoses I should be looking at for lapses in integrity. It's also unclear how to repair the leaks or how many PSI to pump the system up to.

I suppose it's also possible that I am not even hearing a leak and that it's just a worn turbo. How much play is normal in a turbo shaft? I have seen a bunch of contradicting videos/statements about this.

Any help would be great; I don't want to screw something up!

 

[9!'clipseDOHC]

Damn it wasn't the BOV. Oh well, glad I tried. Now I have nothing to do but a boost leak test. If I ever get around to it; it seems very intimidating. 9!'clipseDOHC, the instructions you linked don't really explain what seals/hoses I should be looking at for lapses in integrity. It's also unclear how to repair the leaks or how many PSI to pump the system up to.

I suppose it's also possible that I am not even hearing a leak and that it's just a worn turbo. How much play is normal in a turbo shaft? I have seen a bunch of contradicting videos/statements about this.

Any help would be great; I don't want to screw something up!

Check your entire intake track: intercooler, pipes, couplings, all vacuum lines (TB, BOV, FPR, break booster, etc), fuel injector seals, TB gaskets, IM gasket, BOV, Turbo (compressor cover), PCV valve (pop the oil cap and see if you hear air rushing into the head), BISS screw, etc. If it is leaking, replace, tighten, or repair, depending on what it is.

I would say to pressure test at least up to the level of boost that your run or about 5 psi above what you run. For stock boost check it from 15-18 psi.

Minimal side to side and zero in and out is good. If you can wiggle it all around, you've got problems.