[Torgus]

My buddies 09 335xi when at part throttle you hear this psh psh psh sound. Originally I thought it was the BOV opening under part throttle which made no sense as the manifold did not have vacuum to pull the BOV open.

You can hear it good at around 23 seconds in.

At WOT the BOV acts normally. At Part to Mid this psh psh psh happens and it feels like lost boost pressure.

Anyone have any ideas?

I can get a log posted if needed. Thanks in advance.

[ClaudeColp]

This is my car. Burgers for anyone that can figure this shit out!

[stafebak]

Running JB4?

[Torgus]

Nope MHD OTS map. He has no IC or DP installed so just the low 93 map.

He says he is losing boost when that happens. I'll have him post a log WOT and part throttle for when this happens.

[b1mmr]

I would start here Upgrade your Tial BOV vacuum line! http://www.e90post.com/forums/showthread.php?t=1161102

[b1mmr]

Originally Posted by Torgus

Nope MHD OTS map. He has no IC or DP installed so just the low 93 map.

He says he is losing boost when that happens. I'll have him post a log WOT and part throttle for when this happens.

Is it a legitimate tial bov, if so, what spring is your friend running in it? Boost is what closes your bov (with the help of a spring). So firstly you need a hose of proper size from the manifold to the bov, and secondly you need a spring that is able to overcome the vacuum of your manifold while at idle on a warm engine (to seat the valve in the shut position). In other words an 11 pound tial spring.

[Torgus]

Originally Posted by b1mmr

Is it a legitimate tial bov, if so, what spring is your friend running in it? Boost is what closes your bov (with the help of a spring). So firstly you need a hose of proper size from the manifold to the bov, and secondly you need a spring that is able to overcome the vacuum of your manifold while at idle on a warm engine (to seat the valve in the shut position). In other words an 11 pound tial spring.

We upgraded his line to the 1/4 size the other day when we walnut blasted. no change.

He has my tial BOV on there with my 11lb spring. It works flawlessly on my car. he also has a knock off BOV and it does the same thing. We only swapped in my genuine tial BOV to be sure that was not the issue.

He had some vanos issues and replaced them with non oem. No codes...I wonder if that could be an issue.

He has 2 rear o2 sensor heater failure codes(new o2s are in the mail) but I can't imagine they would give him these issue...he had the issue before iirc.

Thanks for the suggestions guys!

[b1mmr]

Originally Posted by Torgus

We upgraded his line to the 1/4 size the other day when we walnut blasted. no change.

He has my tial BOV on there with my 11lb spring. It works flawlessly on my car. he also has a knock off BOV and it does the same thing. We only swapped in my genuine tial BOV to be sure that was not the issue.

He had some vanos issues and replaced them with non oem. No codes...I wonder if that could be an issue.

He has 2 o2 sensor codes(new o2s are in the mail) but I can't imagine they would give him these issues...

Thanks for the suggestions guys!

Good to see you're on top of it.. I suppose vanos could be the culprit but beyond what I have already suggested I have no clue. I wish you the best of luck and will stay tuned.

[Torgus]

Just wanted to post an update. He also was unable to build boost, then started to get all these weird misfire codes etc. We gave up and brought it to a shop.

Shop confirmed one downpipe basically fully clogged. Never heard of that happening on this platform but I guess anything is possible. We had catless XI downpipes from VRSF sitting in the garage we were going to install so we gave it to the mechanic to install. Problem went away. He has boost again!!!

Only issue is I don't think you can really check your cats until you remove the downpipes which means you might as well have aftermarkets on hand.

Just wanted to update the thread. if you have any of these issues it might be a clogged cat.

TLR go catless downpipes.

[Socket]

Glad your mate found the problem

Meanwhile for peeps running Tials, I say ditch em and get a GFB SV50 (Go Fast Bits BOV)
Its adjustable via a locking nut on top of the BOV so you can set it just right for your car. I ended up buying three different Tial springs (not cheap) before switching... solved my weird warbling engine sounds that started up after installing silicon VTT inlets

[Torgus]

Originally Posted by Socket

Glad your mate found the problem

Meanwhile for peeps running Tials, I say ditch em and get a GFB SV50 (Go Fast Bits BOV)
Its adjustable via a locking nut on top of the BOV so you can set it just right for your car. I ended up buying three different Tial springs (not cheap) before switching... solved my weird warbling engine sounds that started up after installing silicon VTT inlets

Thanks for the info man! My Tial is working fine right now but I have heard many with issues after inlet installs. This is good info to have.

[Socket]

Originally Posted by Torgus

Thanks for the info man! My Tial is working fine right now but I have heard many with issues after inlet installs. This is good info to have.

No worries mate, this question comes up from time to time on the forum. For what I can figure out the silicon inlets expand and contract under boost and if the BOV is not venting correctly, it causes turbo flutter and other weird noises.... not that I'm an expert. The solution for me was an adjustable BOV that could be tweaked to suit my set up. Hope this helps someone else out who is having the same problem