Hey Guys,

So my check valve #16 is leaking. I got a replacement valve and trying to swap it out. Access on the top of the engine towards the back is well almost non existent. This is horrible.

I pulled the air box, the plenum piece going to the throttle body, the throttle body itself and a few hoses around there I could get my hands on. The valve is still way back there and one of the clamps is turned around facing the front of the car. I've tried pulling it around with a lot of force and can't budge it and even if I can get it around there's no way to get a pair of pliers in there to undo it.
The clamp closest to the throttle body has moved back a little but it's still pinching and its out of room.

How are you guys getting these things out?

I took a couple pics but they're not the greatest. Cramped space and you really can't see depth in the pic. I may need to get the real camera out instead of the cell phone. I marked a red arrow to the valve in question to be sure I'm going for the right one

 

I replace my valve by lower the engine.

 

^^ yes, loosen the motor mounts to give you that necessary clearance. also needed if you may have to remove the plenum, and getting that back in is such a tight fit we practically had to hammer it into place when i put in the ipd. tight fit is an understatement.

 

Ah so just spin the nut loose from the underside of the car right? I seem to recall they were 18 mm. It's hard see exactly how they attach but I assume the motor is on the lower side of the frame and will move down as I loosen those nuts. I should have thought of that. Will give that whirl tomorrow. Thanks guys.

 

just watch how low you drop it. to far and you will pop the coolant hoses off and coolant goes everywhere. also if you drop the trans mount you can lower it slightly more. be sure to support both engine and trans when lowering them

 

^ yes to support, and to the underside of the mm. i didn't have to mess with the trans mount. once the mm's are even a bit loose, you should have the clearance you'll need. its not *much*, but as noted there aint much to be had lol

 

Well after much struggling and fighting I got that sucker out. Notice the blank spot lol




The infamous check valve #16.



After many hours of getting the new valve in and everything back I discovered this short stub of hose between the plenum and some sort of solenoid was split too.




Found some suitable replacement hose in the stock pile and got that sorted out.




Next I found one of the blow off valves was leaking. This one was tricky because I kept inspecting and re-installing the hose unable to get rid of the leak. I eventually figured out the nipple sticking out of the BOV for the those to slide on is actually a separate piece that threads into it. So removed the whole thing and spun off the piece.




Some teflon tape and re-installed and leak fixed.





Went for a test drive and the good news is mid range is now predictable and drives nice. More responsive I think. However the car still only peaks at 1.0 bar of boost. Everyone says my K24/18g turbos should be 1.25 ~ 1.3 bar. Is it maybe controlled in the tune? Do these cars have programmable waste gates or solenoids controlling the wastegates from the factory? or is it 100% mechanical off the spring?

 

Good work on the #16. That hose is to the N75, another chronic failing point. Now do a proper leak test from the Turbos!

 

^+1 on the pressure testing @ turbo's now and all those parts need to be working in concert ( n75/#16 and one more valve often mistakenly called ANOTHER check valve in the same area of the intake.. like a piece of fishing tackle i cant recall name sorry ) and then yes, the wg's. seems that most all of this "is it right, it it not"? since you are so adept at fixing stuff and even improvising is because you're still struggling with mystery stuff ( tune? is it a 1 bar k16?? or a 1..2 k 24 flash? ) and also wg's on the car. i would see if possibly you have aftermrket "1.0" wg's and really figure out if you have an OLDER 1.0 bar tune which probably ( as you rightly say! ) is not optimal for the hybrid 24's you're currently running, as yeah.. you should see 1.2 at will as i do with 16/24's and a 1.2 OLD cargraphic tune.

pressure test at the turbos once buttoned up and check the wg adjustments by beginning from scratch and they ( iirc?! but dont quote me? ) two full turns of adjuster nuts on the wg's l/r. gotta make sure they opening when/as they should.

1.0 seems inhibited, i think you're right. GL.

 

Pressure testing from the turbos is how I found all those leaks. I put a plug in the driver's side turbo outlet hose




and a plug with a shrader valve in the passenger's side and aired it up with the air compressor




For the wastegates I rigged up a vacuum/pressure gauge with a bicycle pump and aired them up. Unfortunately the gauge only goes to 10 PSI before it swings into a different scale so it's difficult to say exactly but look around 18 PSI or so before they start to swing. Here's a video showing when the wastegates start to swing. This is driver's side but passenger's started swinging at the exact same time on the gauge.

 

that 90* bent tube that was split goes to the n75 valve that controls the wastegates. if you replaced the hose with a straight piece then remounted the n75 you may be pinching the hose down to were its not working properly. check it to see

 

i think your wg's are cracking a bit late? but "we" dont know (a) what they are? and (b) i'm barely able to hang in this and should quite possibly stfu.. BUT i am fairly certain my 1.0 wg actuators are set to open @ 14/maybe 15 psi??

someone pls correct me if i'm wrong. but yours might be cracking open too late. either late or early is obviously going to affect boost particularly sustained.. no??

"The OEM wastegate actuators are set at .7 bar (10.29 PSI) of pressure, which is too low for modified cars". this might be whats goin on.

 

you took my advice and found all sort of issues... My boost leak tester sure does come handy... the trick is knowing what to do next...
markski

 

It looked fine initially but I'll double check it now that it's been through a heat cycle.

Yes I think I have all the boost leaks fixed. I'll get you a datalog as soon as the weather permits.

 

Bumping this thread as I'm in the middle of pressure testing...

Immediately found a leaking check valve, really can't go further until I get that one buttoned up or capped off. With the hard line and quick-disconnect fitting where the hose connects to the turbo inlet, doesn't seem like there is an easy way to seal this off so I guess I'm waiting until I can get and install the check valve.