1G BOV leaking with new UICP?

[jim97gst]

I just installed a FMIC on my car. Right before the install, I was able to hold 20 psi to redline. I did a boost leak test after the install, and found that my 1G BOV was leaking out of the discharge tube. I thought it was odd because at wasn't leaking before, and all I did was swap it over to the new UICP that came with my FMIC. I took it for a test drive, and it won't hold more than 10 psi, so I guess the BOV leak is pretty bad. I looked at my old UICP (Brode), and it seems to have a smaller hole through the flange than my new one, although I'm not positive, and I can't see the hole through the new flange with the BOV installed. I'm thinking that the little hole on the underside of the BOV was covered up before, and isn't now. Is this my problem? Ideas? Like I said, I did a boost leak test to about 15 psi, and the ONLY leak was out of the BOV. Thanks in advance.

 

[oldman]

Are you tapping the BOV line for your mbc? If so, did you remove the mbc during the leak test?

 

[jim97gst]

Nope. I've got a nipple on the J-pipe. On my old setup, I was tapping a little further downstream on the L-pipe on the way to the SMIC. This seems really strange that the BOV seemed to be working fine before. I didn't drop it or anything during the install.

 

[oldman]

Then I would double check the vacuum line to the intake manifold for leaks. You can also either crush it or mod it to hold higher pressure.

 

[jim97gst]

I did another boost leak test and got the same results. I think I'm going to take the easy/expensive way out and treat my car to a new Forge BOV. It's just really bugging me that my BOV started leaking really bad all at once, at the same time I did a mod that doesn't seem like it should have caused this problem. When I get my new BOV, I'm going to mount the old one back on the Brode UICP and see if I can do a boost leak test on it to see what happens. Thanks for your help.

 

[andymoraitis]

I had a similar issue on a crushed BOV. Replacing it solved the problem. I think the Forge is a great choice and with the right spring, it'll hold 24 psi plus without a problem.

Good luck!

Andy

 

[jim97gst]

OK, so I got the Forge BOV. I have 2 boost leaks that I know of right now. There is a very small one where the BOV body meets the flange. I read a post by CanadianTSI and he had the same problem which he solved by just getting the flange welded.

I have another leak, still out of the BOV discharge tube. I've tried both the yellow and blue spring (blue is supposed to hold 23-30psi). I talked to Forge, and they said that it was probably because with the throttle closed, the vacuum line wasn't getting pressure to help keep the valve closed. Does this sound right? I'm going to need to find someone to help me to do a boost leak test like this if I have to keep the throttle open.

As far as driving the car, it is definitely holding boost better than my 1G BOV. However, 1st and 2nd gear hit 20, but then the boost drops down 2-3 psi. 3rd gear and higher seem to hold 20 psi pretty steady. If my boost leaks are causing this, then why only in the lower gears?