Ok guys. For a while now under full throttle the car feels AWESOME up until 5.5 to 6k rpms. Around that rpm (it varies) the stock diverter valve opens up and the car just falls on its face. Its very clear whats going on as there's a whooshing sound, the turbo goes up in pitch and the car looses all its momentum and keels over. I shift to the next gear as soon as this happens and it holds boost and runs like a raped ape until ~6k rpms where it repeats the same process.

Alright, so the stock BOV is bad. I take it to the dealership and tell them it has a boost leak and that its most likely the BOV. They drive the car, note the symptoms I described and then replaced the BOV and checked all the associated induction piping.
THE CAR STILL VENTS BY ITSELF PREMATURELY Do you think its possible that the new valve they installed is also a dud? They said that the valve that came out of the car was definitely shot. BTW, I'm bone stock.

Finally, what is the consensus on aftermarket recirculation valves? What do you guys reccomend? I think I"m getting tired of this factory plastic BS

 

I had the same problem. You have a leak somewhere around your vacume hose. Make sure the clamps are on properly.

 

Same thing here, but mine would hold stock now it makes the EXACT same thing as you and guess what? I tried *3* different stock BOV and the last one I got on now only holds 17PSI the others held 21-22 till 5500ish RPM then it would drop to 15 then to 12. I checked all the hoses on a lift, also changed the boost control solenoid. Tomorrow I am installing a Forge BOV and I will let you know if it fixes it or not. Also a lot of people said it was the hoses but that was not the case with me and I check EVERYONE by removing them and putting them back on. Also thanks to Boost Solutions for having all the parts in stock to trouble shoot this issue as well as the lift to put my car on!

 

Are you over looking that the evo drops boost to around 16psi at 5-6krpm?

just a tought?

This will cause u to have a fall on ur face effect.

 

I know perfectly well that the boost drops a bit as the car revs. What I'm describing has nothing to do with this. The car straight falls on its face and you hear a "Ppfffffffffff" whooshing sound as the POS stock BOV recirculates most of my boost

One thing I have noticed. The valve will hold when the car is started up cold. As soon as the valve itself gets hot from either a few minutes driving or the car idling in the driveway after a quick jaunt, it starts leaking.

I've checked the vac line that leads from the manifold to the BOV. It looks to be in perfect shape and all clamps, etc are there and properly fitted over the vac nipples.

I guess its back to the dealership for BOV # 3

 

If you get it fixed please let me know. Here is a post I did about what we spent 10 hours today working on....

I just wanted to take some time tonight to post this because George took 10 hours of HIS day to help me with my car. If you did not know I had a boost leak with my car, I went to Boost Solutions yesterday at about 11:00am for them to look at my car, 1st George took a look at the hoses then we put the car on the lift and removed all of the plastic’s on the under tray and check all of the hoses and clamps there to make sure it was not leaking from there. Next we put a different stock BOV on the car to see if that would fix it and no dice it had the same problem, we also changed the boost control solenoid and he said he would get a different BOV to test it with tomorrow. Well today I stopped by again @ 11:00 and we tried, 3 stock BOVs, 2 forge valves, and a MONSTER something BOV same deal but the problem did change with each piece, some held better then others but the all leaked. Well around 5 George said let me look at the computer Balanced Performance hooked up, I said sure. We traced all the wires and sure as **** the retards hooked up not 1 but 2 wires wrong, they put a wire that did nothing into the xede for boost control and my idle wire was wrong as well. I paid these people to look at my car and told them I did not care what it cost to get it fixed just fix it. When I left my evo would not idle cold and also the boost was not hooked up, I paid $350 for this sweet *** work they performed and George changed the wires correctly back now it idles and the damn boost control works. I just wanted to post this before any other sucker goes to Balanced to get work done THEY SUCK and there price is higher then anyone else. George fixed 2 things wrong with my car and I am sure we will get this boost leak fixed soon. I would go to Boost Solutions to get ANYTHING done with my car, they are doing the cam gear install as well as fuel pump and anything else that I need done. George took care of me better then ANY shop has done and I had to tell him I had to go because he wanted to work on it more and get the problem fixed not just half *** it and get paid like Balanced did.

 

O.K here is the deal .. the blow off valve is fine ! ! what you have is a leak in the hose that leads to the "blow off" valve ! look at the hose where it goes to the metal "mini" pipe it's not that long ! also check the hose where that pipe also gets vacum/boost signal ! ! what happens is that under boost the valve is blowing open due to the fact that there is not "equal" pressure in both sides of the valve ! ! so there is more pressure on the side of the valve that is on the pressure pipe that leads to the throttle body ! causing it to overcome the spring tension & therfore forcing the valve open ! ! fix the leak in that line leading to the "blow off " valve and that will pressurize the other side of the valve helping it hold tight !! and you will be set ! !

 

What year is your evo and what mods do you have done to it?

 

I have a 03 evo 8 highly moded ..

 

 

Nozzle, I have checked this line, it looks perfect. Also, I understand perfectly how the diverter valve works as I'm very familiar with highly boosted turbo motors. Anyway, one thing that doesn't make sense about the blowing open theory is that while it does seem the valve is "blowing open," the car makes maximum boost pressure earlier in the rev range and by the time the valve (so I hope) starts leaking, the boost has already started to fall from peak. Another curious aspect as I mentioned earlier is that the valve holds boost pretty well until it physcially heats up. Once the valve itself becomes hot from either extended idling or driving, it begins to leak.

 

is the bov on backwards...(NOT FUNNY) ive read it alot!!! RRR

 

For one, if your evo is stock, you should never hear the stock BOV blowing off. You might have a loose IC pipe somewhere that's popping off. Either the valve is bad, or the vac line for the valve is being run from the wrong location. Make sure the BOV line comes from a hard line attached to the front right corner of the engine head.

 

are you seriously asking this

 

I checked all the intercooler pipes myself as well as having the dealership check them. They are fine. I have the correct line running to the valve as its very clear which one its supposed to be (the hard line that runs across the valve cover on the right hand side). Also, I do not have the valve in backwards. The bottom side of the piston faces boost. If you reverse it, the valve really doesn't work at all and you get MAD compressor surge.