Moderators BarManBean Posted March 30, 2015 Moderators Share Posted March 30, 2015 Looking for a bit of help here. There seems to be a sensor of some sort that sits on the passenger head, just in from the valve cover gasket and towards the rear of the car. The plug that connects to the sensor connects from the passenger side of the car. What the heck sensor is this? "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
MrTris Posted March 30, 2015 Share Posted March 30, 2015 Looking for a bit of help here. There seems to be a sensor of some sort that sits on the passenger head, just in from the valve cover gasket and towards the rear of the car. The plug that connects to the sensor connects from the passenger side of the car. What the heck sensor is this? Top or bottom of engine? Have you deleted your TGVs? Link to comment Share on other sites More sharing options...
heiche Posted March 30, 2015 Share Posted March 30, 2015 Looking for a bit of help here. There seems to be a sensor of some sort that sits on the passenger head, just in from the valve cover gasket and towards the rear of the car. The plug that connects to the sensor connects from the passenger side of the car. What the heck sensor is this? cam position sensor? BtSsm - Android app/Bluetooth adapter. LV, logging, gauges and more. For 05-14 Legacy (GT, 2.5, 3.0, 3.6), 02-14 WRX, 04-14 STi, 04-14 FXT, 05-09 OBXT Link to comment Share on other sites More sharing options...
SBT Posted March 30, 2015 Share Posted March 30, 2015 Camshaft sensor. #6 here http://static.opposedforces.com/epc_img/366495109003.png - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
MrTris Posted March 30, 2015 Share Posted March 30, 2015 cam position sensor? Camshaft sensor. #6 here http://static.opposedforces.com/epc_img/366495109003.png This is the most likely piece, and, what I was going to guess, but, needed to know top or bottom first, as, on the B-series heads, there's an identical casting mark for an exhaust cam sensor on the bottom, but no electrical for it. Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted March 30, 2015 Author Moderators Share Posted March 30, 2015 Top or bottom of engine? Have you deleted your TGVs? Top of engine. Basically below the wastegate actuator and upper coolant reservoir. I can see it when I look down in between those two. cam position sensor? Dunno, I'll look into that. I'm asking because I'm smoke / boost leak testing the car and I'm getting NOTHING from the smoke test, but when I pressurize the system I'm getting some bubbling at that sensor, almost like it has a bad gasket there or something similar I'm doing this in response to some elevated learned trim A numbers since flashing my last tune and also removing / reinstalling my intercooler. "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted March 30, 2015 Author Moderators Share Posted March 30, 2015 Yup, must be the camshaft sensor based on those diagrams. Now WhyTF is that seeming to leak?!? "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
MrTris Posted March 30, 2015 Share Posted March 30, 2015 Yup, must be the camshaft sensor based on those diagrams. Now WhyTF is that seeming to leak?!? Increased crankcase pressure is really the only way that would have pressure against it, since it basically sits right over the cams, which are bathed in oil in the VCs. Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted March 30, 2015 Author Moderators Share Posted March 30, 2015 Increased crankcase pressure is really the only way that would have pressure against it, since it basically sits right over the cams, which are bathed in oil in the VCs. That much makes sense since I'm not plugging any hoses at the moment, so I'm certainly pressurizing the case a bit. Only bringing it to 4 or 5psi though. Unsure if this would act as a small vacuum / boost leak under normal conditions...? "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
MrTris Posted March 30, 2015 Share Posted March 30, 2015 That much makes sense since I'm not plugging any hoses at the moment, so I'm certainly pressurizing the case a bit. Only bringing it to 4 or 5psi though. Unsure if this would act as a small vacuum / boost leak under normal conditions...? It shouldn't, since it's crankcase-connected. Unless you had blowby, but, at that point, it's not really a "boost leak". Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted March 30, 2015 Author Moderators Share Posted March 30, 2015 It shouldn't, since it's crankcase-connected. Unless you had blowby, but, at that point, it's not really a "boost leak". So the crankcase isn't pressurized under normal operated conditions, but it IS pressurized under a boost leak test where I don't plug/pinch any inlet hoses? I should maybe start my own thread on this... "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
MTBwrench Posted March 30, 2015 Share Posted March 30, 2015 Yup, must be the camshaft sensor based on those diagrams. Now WhyTF is that seeming to leak?!? I've got the same leak! Except mine is coming from everywhere on top of the block. Clogged PCV? mine likes to leak down the back of the heads, and onto the crossmember/UP. Smells delicious. I don't think it would cause a vacuum/boost leak though. If my[often flawed] logic is correct, when the motor is actually running, pressure isn't sent from the inlet to the breathers, since it's all made after the turbo. It's just getting into the case now because you're applying positive pressure to the pre-turbo piping. (assuming you're testing from there.) MTBwrench's Stage 3 5EAT #racewagon 266awhp/255awtq @17.5psi, Tuned By Graham of Boosted Performance Everyone knows what I taste like. Link to comment Share on other sites More sharing options...
MrTris Posted March 30, 2015 Share Posted March 30, 2015 I've got the same leak! Except mine is coming from everywhere on top of the block. Clogged PCV? mine likes to leak down the back of the heads, and onto the crossmember/UP. Smells delicious. I don't think it would cause a vacuum/boost leak though. If my[often flawed] logic is correct, when the motor is actually running, pressure isn't sent from the inlet to the breathers, since it's all made after the turbo. It's just getting into the case now because you're applying positive pressure to the pre-turbo piping. (assuming you're testing from there.) Yours is probably PCV-related. I would at least change it, since it's cheap to do so, (~$30) and see if the problem persists. BMB, pressure is supposed to be equalized between the two sides, via the crossover hoses that run along the back of the PCV system that's mounted to the back of the intake manifold. Since it's already torn down, maybe go ahead and run those bad boys through the wash to ensure that there's no blockage? Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted March 30, 2015 Author Moderators Share Posted March 30, 2015 Yours is probably PCV-related. I would at least change it, since it's cheap to do so, (~$30) and see if the problem persists. BMB, pressure is supposed to be equalized between the two sides, via the crossover hoses that run along the back of the PCV system that's mounted to the back of the intake manifold. Since it's already torn down, maybe go ahead and run those bad boys through the wash to ensure that there's no blockage? I changed out the whole PCV assembly quite recently, last May I believe. "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted March 30, 2015 Author Moderators Share Posted March 30, 2015 I've got the same leak! Except mine is coming from everywhere on top of the block. Clogged PCV? mine likes to leak down the back of the heads, and onto the crossmember/UP. Smells delicious. I don't think it would cause a vacuum/boost leak though. If my[often flawed] logic is correct, when the motor is actually running, pressure isn't sent from the inlet to the breathers, since it's all made after the turbo. It's just getting into the case now because you're applying positive pressure to the pre-turbo piping. (assuming you're testing from there.) Yours sounds like a bad VCG leak? "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
MrTris Posted March 30, 2015 Share Posted March 30, 2015 I changed out the whole PCV assembly quite recently, last May I believe. Huh. Well, then I guess #ynansb. Link to comment Share on other sites More sharing options...
MTBwrench Posted March 30, 2015 Share Posted March 30, 2015 Yours sounds like a bad VCG leak? I thought so too, but I had the UP off not two months ago and all was dry. No leaks whatsoever. I also noticed the other day both the the PCV and the breather near the center of the block have big oily stains around them, which lead to the back of the block, and down the case. I'm pretty sure it's my PCV malfunctioning, as these leaks are recent and I know it's never been changed. Huh. Well, then I guess #ynansb. No bueno. Time to make a race wagon? Sent from my iPhone using Tapatalk MTBwrench's Stage 3 5EAT #racewagon 266awhp/255awtq @17.5psi, Tuned By Graham of Boosted Performance Everyone knows what I taste like. Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted March 30, 2015 Author Moderators Share Posted March 30, 2015 I pretty much HAVE a race wagon I have plans to pull the motor in the near future for other work anyway. Leak down test then will sort things out . Although I'm not planning to replace the block at this time! "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
SBT Posted March 30, 2015 Share Posted March 30, 2015 So the crankcase isn't pressurized under normal operated conditions, but it IS pressurized under a boost leak test where I don't plug/pinch any inlet hoses? I should maybe start my own thread on this... Under normal operations, the crankcase is constantly pressurized and the outlet is the PCV valve. Sounds like that might be blocked or it (the smoke) would be exiting the CC via the PCV during your smoke testing - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
MrTris Posted March 30, 2015 Share Posted March 30, 2015 Under normal operations, the crankcase is constantly pressurized and the outlet is the PCV valve. Sounds like that might be blocked or it (the smoke) would be exiting the CC via the PCV during your smoke testing . . . and if the PCV is blocked, then it will exit from the oil fill tube or dipstick tube, since both are the biggest paths of least resistence. Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted March 30, 2015 Author Moderators Share Posted March 30, 2015 So possible that PCV is bad after less than a year? Seems odd. "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted March 30, 2015 Author Moderators Share Posted March 30, 2015 FWIW, I *have* had boost leaks go wonky on me recently, meaning they resulted in the dipstick popping out and oil going everywhere... "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted March 30, 2015 Author Moderators Share Posted March 30, 2015 Also. Smoke testing happens under 1psi for reference. I set it up so I can add pressure at the inlet to test for actual "boost only" leaks. "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
SBT Posted March 30, 2015 Share Posted March 30, 2015 You don't want to boost leak test with very much pressure at all - cam and main seals are at risk. I hold the dipstick in and make sure the O-ring on the filler is well-greased, supple, and tight. If you're getting enough pressure in the system to push-out the dipstick, then you're using too much pressure. PCV valves can go bad, and I'm replacing mine this week, as a preventative measure. - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted March 30, 2015 Author Moderators Share Posted March 30, 2015 Yup. I know that now and only go to 4-5psi now Also know that PCVs can go bad which is why I preventatively replaced mine less than 10k miles ago Either way, I guess I'll take a look at potentially replacing it again, but that seems a bit silly. "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
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