Even though i am too lazy to look up the proper spelling, my boost control solenoid is going out, I believe. I don't think I have a vacum leak, but I know that my wastegate is not staying shut during full boost. I read a post in this forum by a guy with a similar problem, his dealer told him it was the solenoid going bad. Makes sense to me...either way, my turbo is not as loud under full boost, I'm down on power, which leads me to believe w/g problem....anyone else have this problem with their EVO? I find it hard to believe that my solenoid only lasted 1600 miles, but it is a

 

hmmm, just read an identical post to the one I just put up.....

 

It actually may not be the solenoid.. It could be the weather, or even if you have the stock diverter valve, for some reason the spring in that thing fatigues and begins to leak.. When I took mine out of the car after feeling like something was wrong, I Noticed the body had a crack in it.

I have the stock solenoid, plus I'm controlling it with the UTEC..

There's a few things that I noticed when I made modifications to the car.. its calibrated to the pressure that is produced at the scroll housing.. so If you've made modifications to your intake/exhaust, you effect the calibration on the solenoid and you end up needing to somehow adjust for it too..

You really need to tell us exactly what you've changed in order to be completely certain, and the things you've changed prior to noticing the car felt different..

What I did with the UTEC was to remove the restrictor at the solenoid (replace the line from th T-fitting to the solenoid) with a 4mm silicone line, I also installed their ABC (Auxiliary boost controller) to adjust the bleed so it doesnt spike..

You need to be certain that your producing enough pressure from the vacuum/boost source, to the boost control lines, otherwise you'll be bleeding the same air, but the signal may be weaker and therefore isn't keeping the wastegate actuator closed at as high a pressure..

If you've taken the boost lines off, you might have hooked up the lines that goes to the actuator, and the line that goes to the charge pipe backwards since one has a restrictor and the other doesnt.. make sure the one with the primary restrictor goes to the vacuum source.

 

problem with that, my car is BONE stock. I haven't even changed the oil myself, as it only has 1600 miles. I've had the oil changed, just so there was a record, at 600 miles, but that's all I've done to the car. I did notice, though, that this problem only reared it's head after the car had been running for a while, like 3 hours+..... is there some sort of intake air temp. gague on these cars? I don't remember correctly, but didn't the DSM have one that was at the MAF location? Car senses too hot air, restricts boost? I'm gonna take her to the dealer tomorrow, odds are, he'll find no problem.....

 

Yes, I think it has two temp sensors that can cause the car to run at low boost.. the Air intake temp sensor which is part of the MAF, and the coolant temp sensor.. If the car is running very hot, it will switch to a secondary map which will cause it to be down on power, I don't know if the boost solenoid will open at a lower RPM or not though.. You might want to tighten all of your clamps on the DV and other intercooler hoses, I hear they commonly work themselves loose on the cars when their new (I hadn't experienced it, but my dealership was very meticulous in prepping the car and during its first service)

My car DID have a defective boost solenoid, it was stuck closed so it always produced 19.5psi of boost until one day when I brought it in for service (third service I think) and it felt weaker, then I noticed the solenoid began working again or they replaced it however their documentation stated nothing about it being serviced.

 

I thought so. I think what's happening here is that the engine bay temp is so hot, it's affecting the intake air temp. after a period of time. Kind of stupid, putting the air temp sensor before the intercooler. i would almost have to replace my ECU with a standalone unit to override this, no? If this sensor is integrated in the MAS itself, there's no way to relocate or over ride it....