svt_lightning01

iTrader: (1)

Okay so I recently installed an autometer boost gauge and an aem eugo. The eugo gauge was defective and another is o the way. In the meantime my boost is showing about 20-21 lbs at 3500 ish rpms but it never tapers it continues to climb and wouldn't stop except for me letting out of the throttle obviously to save the motor haha. I checked all of my lines and even ran a loop line from turbo outlet to wastegate to see if it was my mbc. No change I thought wastegate pressure would take over but even with the loop vacuum line for wastegate pressure it still builds 25+ and never tapers of stops. I checked the wastegate and threads are showing on the rod telling me that it hasn't been tightened. Four threads worth of rod stick out of the nut. This all leads me to thing the wastegate is bad. What do you guys think?

awdordie

iTrader: (1)

For one what ur describing is not boost spike. Its boost creep. Boost spike is where the turbo builds boost really fast goes past the wastegate setting before it opens fully then drops back to the regular setting. With that being said and it being boost creep, have u recently changed the turbo, exhaust, or anything else other than a boost gauge and controller? Boost creep occurs when the wastegate cannot flow enough out around the turbo so it continues through the turbine building more boost than it should.

xmaciek82x

iTrader: (14)

Yes, it's boost creep not spike. A better flowing o2 housing will fix that.

svt_lightning01

iTrader: (1)

It has an aftermarket o2 housing not sure what type. It came on the car. And no other mods besides the gauges and the mbc. It is possible it's the wastegate? With an aftermarket o2 housing that would rule that out correct? I mean it set up to run wastegate pressure a's it sets so whatever the problem is doesn't involve the mbc because it's not even hooked up.

joseph143

iTrader: (8)

how fast does it climb to 25psi? you may have the fp wastegate... does it climb to 25 by like 4k or does it take it till later on like 5-6k.... if it doesnt stop at 21 and immediately climbs then i'd call it the wastegate pressure... if its a slow gradual climb then i'd say its a wastegate flow issue... i.e. o2 housing or stinking flapper...

svt_lightning01

iTrader: (1)

okay if im driving say 40 mph down the road in fourth at a relatively low rpm like 2500 ish. If i floor it it almost instantly boosts to 12-14 psi by around 3500 rpm. Then from the on its a steady climb to eternity. I have completely taken the mbc out of the equation. I have a vacuum line looped from the wastegate to the turbo outlet. Then the bov line that runs into the intake manifold hard line, That is where i am reading boost pressure. I have tried it with the stock boost selenoid capped off, with the nipple open to air, and with the solenoid completely removed (yes cel haha). All of these things produce the same result with or without the mbc. When it was hooked up it was one line from mbc to bov and one from turbo outlet to mbc. All produce the same result of a rapid spool to about 12-15psi then a creep from there to eternity. The o2 housing is aftermarket. i don't know anything about it. No changes have been made i bought the car and to my knowledge it has been doing this since i bought it. The only thing i'm left with is the wastegate. The wastegate appears to be the oem gate. I haven't removed it but does the 25psi wastegate look the exact same?

svt_lightning01

iTrader: (1)

also how would i tell if the turbo is stock or not along with the wastegate? It all looks stock and i know the turbo says 16g.

Kings Fan

iTrader: (2)

Sounds like your O2 is causing your boost creep, some no-name/ebay O2s were known to cause boost creep.

joseph143

iTrader: (8)

yes... i have a pic of them together.... the flash kinda kills it... but the stock is a goldish bronzeish color and the fp gate is pure silver...

stock is in front... 25psi gate is in back....

both are for sale btw lol....

ps.... i would go find a install manual for a hallman MBC to check if the routing of the lines is correct... to me it sounds all ****ed up...

should be turbo outlet to mbc/ mbc to wastegate... or with the stock ebc turbo to ebc/ to mbc/ mbc to wastegate.... unless you have an external wastegate... then it gets crazy... however i've only ran EBC solenoids so i'm not certain... so check

svt_lightning01

iTrader: (1)

mine is definitely stock. Its bronze for sure. So would you guys change the o2 housing or try the wastegate first? Oh i forgot, kind of a big deal sorry haha, the car was wrecked in the front when i got it. I replaced radiator support,radiator, ac condenser, condenser fan, etc. All of the impact was directed towards the heat shields that cover the wastegate and rod. The shields didn't break but they are heavily dented. This is what makes me think maybe the wastegate is damaged.

joseph143

iTrader: (8)

hahah... huge deal!!!

if the wastegate rod is bent it increases the crank pressure by an enormous amount... see the rod on the back wastegate... thats a perfect example of what it should look like...

also the flapper dohicky.. idk what to call it... where the wastegate connects to the flapper...
if that is bend... holey ****!!!!!! it wont open completely and create the boost creep effect exactly as how the one post above describes

svt_lightning01

iTrader: (1)

okay i may replace the waste gate. Used stock ones seem to be floating around quite frequently. I still have both covers on the car so it will be enough trouble to get it off i may as well change it while its out. i don't think that the one on it has been tightened. I see four threads worth of rod still exterior to the nut. i cant visibly see if the rod is bent i didnt pull the lower cover off because i didnt have an 02 sensor socket to remove it and remove the lower cover. Will the 02 housing have a brand on it?

svt_lightning01

iTrader: (1)

i think i may just order one and change them out. hopefully this will cure my problem. Is there any easier way to get the heat shields off? It looks like the radiator removed would make it 100x easier.

svt_lightning01

iTrader: (1)

oh btw that is how i have the lines ran. turbo outlet to mbc then mbc to wastergate.

svt_lightning01

iTrader: (1)

It's like it wants to stay at wastegate but something gives up at 4k and boost takes off. You guys think my flap on the gate is messed up? Or could the o2 housing be restricted with carbon?