vwynn

iTrader: (4)

ok so i finally got my BOV Flange welded and installed the Vortech Max flow BOV on before the MAF so i can just vent it.. everything went well and sounds great until my CEL pops up and my car doesnt feel 100% anymore.

My brother ran a scan and found that the Knock Sensor 1 code was showing.

could getting a BOV destroy my knock?

CODE: P0325

99 GS3

iTrader: (14)

How far away from the maf did you mount the valve? My bov is on the hot side of the intercooler just after the turbo and the maf is on the cold side just before the tb so there is plenty of distance between them to minimize turbulance/air flow changes on the maf. I've had no issues with knock at all.

Did you clear it and run the car somemore and see if the knock code came right back again?

vwynn

iTrader: (4)

i got the flange welded after the intercooler.. which is the cold side i guess .. DAMMIT i knew i shoulda had it welded before the intercooler..



Its on the shortest pipe out of all my piping.. near where my foglight would be. the small 45 degree style pipe.





I cleared it about 3 times. and the CEL keeps popping up. I even tried removing the SAFC tune and running with the stock ECU with no piggy and the code still pops up.

I guess my knock sensor took a poop?

vwynn

iTrader: (4)

question: is it bad to drive the car with that sensor out?? if i do if i dont push it hard i should be ok right?

GS4_Fiend

iTrader: (22)

The purpose of a Knock Sensor is when it sense the engine knocking, it will retard the timing until it stops knocking. Also, if the Knock Sensor gets a vibration, that too would cause the knock sensor to go out of whack and retard timing. Isolate the vibration, returning back everything to previous was, if could still pops up, then KS is bad.

vwynn

iTrader: (4)

good info.

Ok so i reset the car again and this time ram the car with the BOV vacuum line off (pretty much doesnt let it open)

the CEL didnt pop up yet

then i put back the hose and after drove it less than 100 meters n bam CEL is on.

im going to drive it without the hose for a little longer to conclude if the BOV is causing this. There is a way to tune it with the BOV right via the SAFCII??

vwynn

iTrader: (4)

ok drove the car some more with the BOV disconnected and the CEL finally popped up again :|.. i think my knock sensor died or something.. car runs sluggish and i can feel it shuddering as the RPM increases. FML

guess its now time to remove the whole intake mani and replace knock sensors??

question now is... OEM or parts from Amazon? lol

GS4_Fiend

iTrader: (22)

I would say get OEM and save the hassle..

vwynn

iTrader: (4)

Code: P0325

GS4_Fiend

iTrader: (22)

P0325 - Knock Sensor Malfunction

No knock sensor 1 signal to ECM with engine speed between 1,700 rpm and 5,400 rpm

Could be open/short circuit in Knock Sensor. Or Knock Sensor could be loose because of vibrations. Last would be bad ECM, which I Doubt it.

BLK13X

Hang on, you have your BOV mounted before the MAF? Wouldn't that cause the MAF to send the wrong voltage signal to the ECU, hence the car throwing a fit?

Have you tried plumbing the BOV back into the piping so it recirculates the air as opposed to venting?

sinistervr

iTrader: (1)

only thing a bov in front of the maf will do is cause the car to wanna stall when letting off, the car is seeing a certain amount of air, and its providing enough fuel. so when you blow off you are releasing some of that air. and the fueling isnt correct

speedaddic

iTrader: (10)

should've put the BOV on the other pipe closest to the Supercharger...the BOV helps prevent boost surge to your compressor wheel.

I don't think your BOV is the cause of your problems with the knock sensor. Just a coincedence, imo...

vwynn

iTrader: (4)

Im pretty sure the sensor just took a poop. could be age or the stress the supercharger is causing on my engine... also dont forget i have not gotten this car properly tuned.

The BOV is placed before the MAF so its safe to vent to atmosphere. I dont get any hesitation when i let off the throttle even at higher rpm when boost has been building. If it was palced after the maf (closer to engine) then ide have to recirc it which sucks cuz i lose that sound

yup

ive read mixed things about BOV placement... i.e. best to put it on the cold side.. or best to put it on the hot side. i just copied LALEX's placement LOL also iono if its better to have the air move a smaller distance towards atmosphere (cold placement) vs going all the way back through the intercooler and more pipes before vent (hot placement)

i haz no idea.

i have a feeling it might be coincidental since... my car started to fall apart after boost LOL

FML

99 GS3

iTrader: (14)

That's what I'm thinking also. I'm not sure on the 400 but the 300 knock sensors have a thin/tiny little wire hooking up to it and is super easy to break, so I would just check the connection as well. When removing knock sensor connectors previously I've had the wire just fall right off the connector when touching it.


The knock issue wouldn't have anything to do with hot or cold side placement. You can read for hours all day the arguments promoting either location, but as speedaddic mentioned it is there to protect the compressor, so basically as long as you don't have compressor surge the placement is fine, and it's doesn't really matter. It comes into play when running blow-thru maf and mounting too close to, or after the maf.

You shouldn't really have stall issues in blow-thru, most people with stalling issues are typically running pull-thru pre turbo mafs and blowing off.

If moving placement of the BOV has a substantial effect on a setup there are usually other issues like a poor source for vacuum or to small of a vacuum line used, too small of a bov for the turbo, or if a spring based unit like a tial maybe the wrong spring selected for the -hg the car pulls.