[jayrosen]

Bypass Valve / BOV did not function; now functions too well

I looked around the forum for an answer to this but I wasn't quite sure what to search for so here's a brief history of the problem:

I bought a 2007 GXP last week that looks like it has a stock turbo with a Fujita aftermarket air intake. The bypass valve/BOV was not operational when I bought the car (I heard a fluttering when decelerating) and the check engine light was on. Used car dealer said that's just how it is. Took the car to GM dealership and they said they couldn't do anything since it was not 100% stock. Performance was good until yesterday when I noticed that car was a bit sluggish. It seemed to be worse this morning and I found a post on this forum that said an ECM reset could fix it. So I unplugged the ECM for about 30 min. Now the bypass valve/BOV seems to function (no more flutter and I heard the pressure release) but any slight reduction in throttle makes the valve open. At low speeds this makes driving a bit jerky (the only way I can describe it).

Any suggestions would be greatly appreciated since neither the used car dealer nor GM seem to know anything.

Jason

 

[glake89]

Find a different GM dealer.

 

[GMCustomerSvc]

I looked around the forum for an answer to this but I wasn't quite sure what to search for so here's a brief history of the problem:

I bought a 2007 GXP last week that looks like it has a stock turbo with a Fujita aftermarket air intake. The wastegate was not operational when I bought the car (I heard a fluttering when decelerating) and the check engine light was on. Used car dealer said that's just how it is. Took the car to GM dealership and they said they couldn't do anything since it was not 100% stock. Performance was good until yesterday when I noticed that car was a bit sluggish. It seemed to be worse this morning and I found a post on this forum that said an ECM reset could fix it. So I unplugged the ECM for about 30 min. Now the wastegate seems to function (no more flutter and I heard the pressure release) but any slight reduction in throttle makes the wastegate open. At low speeds this makes driving a bit jerky (the only way I can describe it).

Any suggestions would be greatly appreciated since neither the used car dealer nor GM seem to know anything.

Jason

Hello Jason,

I would like to look into this issue and get some clarification. Private message
me the details including the VIN and mention this thread.

Safe travels,

Jennifer T,
GM Customer Care

 

[rob the elder]

The sound you are hearing is likely the result of removal of the factory air box. The factory box muffles most of the intake sound. Any cold air intake will not mitigate the intake noise and you hear it loud and often.

There are many posts concerning issues with the Fujita CAI from the 2007 time frame. Most deal with oil from the filter contaminating the MAF sensor.

Can you tell us what codes are being shown? Then we might be able to offer some better advice.

 

[TX08manualGXP]

we are lucky to have you Rob. and you too Jennifer. I love this place!

 

[The_Ghost]

I have a fujita....your going to hear what sounds like fluttering between 1/4 and 1/3 throttle is actually the air being sucked into the CAI. I will post video later of what im talking about. Mine actualy sounds like rocks being tumbled in the CAI....

 

[TomatoSoup]

I didn't think the Fujita was an oiled filter. I think the K&N is the one Rob is referring to.

However, I have heard that the Fujita is one that can cause turbulent air flow over the MAF and result in driveability issues. This apparently happens on a case-by-case basis (does not apply to all).

My recommendation to the OP would be to replace the CAI with stock (or DDM CAI, or GMPP CAI).

 

[DaveOC]

My understanding was that the Fujita used a K&N (oiled) filter. The original Fujita CAIs for the GXP caused issues. I don't know about more recent versions. I agree with TS, dump the Fujita for a GMPP CAI.

 

[Robssol]

I've been running a DEJON cai with a K&N filter for almost three yr. with no problems. Knock on wood.

A used car lot that would sell a car with a problem, not really surprising. A dealership that won't take your money. That is surprising!

 

[shabby]

Used car dealer said that's just how it is.

Funny guy, new cars don't come with check engine lights flashing from the factory.
I would ditch the fujita intake too, its smaller than the stock pipe and messes up your maf readings.

 

[The_Ghost]

I've never had an issue with my Fujita (knock on wood)....but I said I never had the rear end leak and a week later there were drips on my driveway....said I never lost a drop of coolant and a week later had the waterpump go..... So I'm sure in the next week I'll have an issue.... :lol:

My Fujita DOES NOT have an oiled filter.....

 

[jayrosen]

update

Ok so here's an update. I am guessing my ECU took the first driving cycle to calibrate and now I am back to my original problem of the wastegate not opening on deceleration with the flutter back. I am pretty sure the flutter noise is the air flowing in the wrong direction and hitting the turbo fan since the noise was not present with the wastegate operating. I also attached a pic of the part # on the turbo housing which searching for results in an OEM turbo. The CAI is fujita all the way from this housing to the manifold. Also the check engine light is back on but performance is now back to what it was when I bought the car.

 

[rob the elder]

I have seen other posts that stated people were experiencing challenges with the Fujita CAI. Here are a few oldies for consumption.:thumbs:

It is because of these posts that I believed that the FJ CAI is oiled.

http://www.solsticeforum.com/forum/f64/another-fujita-cai-question-43483/

http://www.solsticeforum.com/forum/f64/fujita-gm-cai-46864/

http://www.solsticeforum.com/forum/f12/fujita-cai-filter-cleaning-62720/

basically its a million mile filter meaning u will only need this aslong as it dont get truely destroyed. they are all about the same as far as taking care. you should every 3 oil changes clean it. what u do is lossen the clamp holding the filter on(flat head screwdriver) and take it off.next using warm water outta your sink or tub wash with warm water and like carwash. then let air dry COMPLETELY. then you will need to reoil it to keep it nice n fresh. I suggest the Kn N recharge kit found at pepboys and most auto supply stores. you spray on the oil and let dry a bit and back in booom goood to go. all and all in AZ idsay ur down like a hour.

 

[jayrosen]

I have seen other posts that stated people were experiencing challenges with the Fujita CAI. Here are a few oldies for consumption.:thumbs:

It is because of these posts that I believed that the FJ CAI is oiled.

http://www.solsticeforum.com/forum/f64/another-fujita-cai-question-43483/

http://www.solsticeforum.com/forum/f64/fujita-gm-cai-46864/

http://www.solsticeforum.com/forum/f12/fujita-cai-filter-cleaning-62720/

basically its a million mile filter meaning u will only need this aslong as it dont get truely destroyed. they are all about the same as far as taking care. you should every 3 oil changes clean it. what u do is lossen the clamp holding the filter on(flat head screwdriver) and take it off.next using warm water outta your sink or tub wash with warm water and like carwash. then let air dry COMPLETELY. then you will need to reoil it to keep it nice n fresh. I suggest the Kn N recharge kit found at pepboys and most auto supply stores. you spray on the oil and let dry a bit and back in booom goood to go. all and all in AZ idsay ur down like a hour.

Thanks for the suggestion. I'm gonna try cleaning the filter and sensor tonight and see how it goes.

-J

 

[GMCustomerSvc]

we are lucky to have you Rob. and you too Jennifer. I love this place!

TX06manual,

Thank you! I am happy to assist.

Safe travels my friend.

Jennifer T,
GM Customer Care

 

[shabby]

Ok so here's an update. I am guessing my ECU took the first driving cycle to calibrate and now I am back to my original problem of the wastegate not opening on deceleration with the flutter back.

That's the blow off valve, the wastegate is on the exhaust side.
What cel is popping up?

 

[The_Ghost]

Can you post of a pic of the intercooler tube going to the intercooler from the turbo and intake by the turbo? I'm wondering if he doesn't have a BOV, rather then the integral one. Just my $.02 Definetly his BOV though....good catch shabby! If you do have an integral BOV, maybe the previous owner put too stiff a spring in it...

I don't know how much you know about the Solstice/Sky, but the BOV is right in the turbo itself.....it's the little orange/yellow cap on the turbo facing the front of the car. That would still be there with an aftermarket BOV, but you would have a tube going from the intake to the intercooler piping....

 

[Racer_X]

Okay lets be clear here...

First, the beige cap is your internal BOV

Second, there should be a vacuum tube that connect from that BOV to a three way vacuum junction- which is on your intake manifold- closest to the radiator.

Third, the fact that the unit is not functioning makes me think that the original owner attempted to put in a heavier spring (i.e. Dejon) and installed it incorrectly. Using a 10mm wrench or socket, take the cap off and make sure that the diaphragm isn't ripped, or that the spring is BEHIND the diaphragm or even there. Basically the unit should be whole- if not... block it off and install a vent to atmosphere unit (i.e. HKS SSQV, or Synapse) (which is the cheapest way to fix it), or run the Hahn recirc kit.

Fourth, drop by an autozone and have the codes read, because it is likely that you have either a vacuum leak or a killed MAF sensor (I have an extra one if need it 25.00).

Also take LOTSA (a whole lotta) pictures of the motor, it sounds like stuff might be missing.

Cheers,

Racer_X

 

[jayrosen]

Okay lets be clear here...

First, the beige cap is your internal BOV

Second, there should be a vacuum tube that connect from that BOV to a three way vacuum junction- which is on your intake manifold- closest to the radiator.

Third, the fact that the unit is not functioning makes me think that the original owner attempted to put in a heavier spring (i.e. Dejon) and installed it incorrectly. Using a 10mm wrench or socket, take the cap off and make sure that the diaphragm isn't ripped, or that the spring is BEHIND the diaphragm or even there. Basically the unit should be whole- if not... block it off and install a vent to atmosphere unit (i.e. HKS SSQV, or Synapse) (which is the cheapest way to fix it), or run the Hahn recirc kit.

Fourth, drop by an autozone and have the codes read, because it is likely that you have either a vacuum leak or a killed MAF sensor (I have an extra one if need it 25.00).

Also take LOTSA (a whole lotta) pictures of the motor, it sounds like stuff might be missing.

Cheers,

Racer_X

Ok I apparently had no idea what a wastegate is (thought it was another name for a by pass valve) :willy: but now I do. So yes, it was the BPV I was referring to not opening. I do have a vacuum line going to it and it seems intact. When I reset the ECM the other day, the BPV seemed to function properly but after stopping and restarting the car it went back to non-functioning mode.

Since the valve is internal to the turbo, is it purely the vacuum line that regulates the open/closed state? Is there a quality BOV that can replace this with no mods to the turbo itself?

I will take a ton of photos tonight and post them. Thanks for all of your help guys & gals...

 

[TomatoSoup]

How are you sure it's the BOV that's not working? You seem to be basing this on symptoms that could easily be caused by something else, specifically the Fujita.