Got my car washed on sunday, in chicago, it wasn't too cold at the time, but it did dip to like 2 degrees in the evening. I hadn't boosted in a while, and i gun it in second and i hit instant fuel cut, cel flashed a number of times for an overboost code which is to be expected. Its like my car's wastegate is welded (frozen) shut. obviously this is impossible because ice would not make it under the hood. I have checked the WGA, WGA rod, MBC, lines, etc...everything appears to be ok. Is it possible my MBC is frozen on the inside which makes the ball and spring unable to move and isn't opening the wasegate? It sure feels like it, this is no spike. this is overboost. anyone have any ideas? thanks!

 

i wouldn't rule out anything being frozen shut or open, but i doubt it. I live in North Dakota where we see temps below 0 EVERY night and i've yet to have a problem like that. 2 degrees isn't enough to cause problems like that i would guess? If you'd like to test your theory however, take your car to a garage or something enclosed and warm and let it sit for a while. See if it reacts in the same way? Just yesturday, i was out doing pulls to set my MBC correctly while it was -3. No problems here.

 

it really shoudlnt freeze warm up the car for a few minutes the temperature under the hood should be enough to melt anything if its frozen, or try to put the car in a garage for a night and see if the problem still persist, i really doubt it would be from something freezing, check over your hoses again

 

When was the last time that you boosted? The temperature definately affects the amount of boost you will make. I too live in Chicago and can see differences between 3-4psi depending on how cold it gets. I am guessing that if you turn down you MBC when it gets really cold you will be back to normal

 

I think I am going to take out my MBC at lunchtime and bring it in, see what happens. I dont really have a garage to put it in until work on saturday. This is troubling because it only happened after that wash, it been cold for a while here and ive had no prob's...

 

I boost about once a day usually full boost. And ive had to turn down the mbc a tad before because of overboost. This isn't like that though. Before it wouldn't overboost before MAYBE 5500 RPM or so. now its instant and doesn't creep, it JUMPS to 2 bar and beyond, I've never seen over 1.6 before this.

 

overboosting a couple PSI is one thing but over 2 bar is a different story, thats around 27-30 psi...not good. Your WGA could not be frozen b/c of the extreme heat around your turbo, there has to be something wrong with your MBC...

 

to get 2 bar, it has to be shut closed. conect the wg line directly to turbo compressor, then if everything is fine it will only have 12-14 psi, this way u know your wg is fine.

good luck