6G Celicas Forums

my wastegate was bad because it was creeping like crazy

Internal wastegates show a few symptoms of going bad... It works with a diaphragm that pushes a spring which in turn moves the wastegate flapper.

If the diaphragm is ripped or leaking, then it will fail to properly push the spring to open the wastegate flapper. This would cause abnormal boost spikes and also boost creep. As RPM increases, the boost reference signal (vac line to wastegate) is leaked out and the diaphragm no longer does its job controlling the movement of the flapper properly.

If the wastegate spring has fatigued from aging or thousands of heatcycles, then it you would get wastegate creep. This is when the wastegate flapper prematurely opens as exhaust pressure overcomes the fatigued spring in the wastegate, forcing it to open before it builds full boost. You will get a really laggy turbo and boost takes forever to build.

i think that was what was happening to me, as i accelerate it would be real sluggish but my boost guage would be reading 15 psi (what i had it set to by the MBC) I thought it was real strange

99.999% of the time, the problem is something other then your wastegate. aftermarket downpipes or incorrectly set boost controllers are the cause of most of these problems. what gear did you set your boost in, and how much does it creep by?



you probably had a boost leak and didn't realize it or that flimsy relocation bracket that tweak made to clock your turbo wasn't sturdy enough. internal wastegates almost never fail.

This post has been edited by lagos: Dec 13, 2007 - 4:23 PM

i had the stock 2inch dp BUT i did have a XS power MBC (heard they were crappy). I dont understand about setting the boost though, what do you mean what gear did i set it in?
I think at the time, i had it all the way open, but the car was still sluggish. sheesh, i still have alot to learn.

when you set your boost you have to set it in 4th gear. some people will try to set 15psi in 2nd or 3rd and then wonder why they hit 18psi on the highway.

it did go over 15 a few times but usually when it was pretty cold when setting the mbc i didnt know i had to choose a gear

electronic boost controller FTW!!!11!1

i dont know about EBC's too tempting i like manual's (abeit inconvenient)

Yea.. I mean whats the point of an EBC really.. It keeps you from overboosting in different temperature conditions and it gives you the ease of setting and forgetting.. not to mention all the extra readings that some of them display and being able to have a low boost and high boost setting or even using an extremely low boost wastegate spring so you can pretty much disable boost when you want to with out having to get out of the car and take a guess when you turn the knob on that stone age device they call a manual boost controller.

Silly product if you ask me.

YEAH! EXACTLY WHAT I WAS SAYING!

sarcasim! just what i wanted for christmas!!!

This post has been edited by easternpiro1: Dec 21, 2007 - 1:38 PM