gropingpriest

So the other day I started noticing a more pronounced whistling sound on top of the normal turbo spool sounds. Lately I've just been commuting in my Cobalt, e.g. I haven't been getting on it and building up much boost. Anyway, the sound was starting to bug me so I decided to floor it and make sure I still had proper boost.

Well, my boost gauge only went up to 10 psi instead of the normal 14 or 16 (I'm stock). I tried again later in the day and it still happened.

Also, I know sometimes the radiator fan will still run after you turn the car off on a turbo car, but to my memory that's never happened for me before... until today. So I can't help but think it's related.

Assuming it is a boost leak somewhere, what's the best course of diagnosing/fixing? Also, does anyone know if this is an easy fix or about how many labor hours to fix it? My job doesn't leave me much time to fix it myself especially with end of 2nd quarter approaching, so I'd probably pay someone to do the job assuming it's reasonable!

Again, my car is bone stock and is at 80,000 miles.

Tdubbs

If it's a boost leak, best bet would be build/buy a leak tester and pressurize the intake pre-turbo to check the entire system. Upper charge pipes are known for cracking, as are the intercooler end tanks. Usually they blow from higher boost, but with the mileage it's possible to break them just from so many heat cycles.

First things first though, I'd look over everything and see if there are any obvious things, like broken ducts/intercooler/hoses popped off/etc.

gropingpriest

Thanks, I'll take a look. I drove for like a week in the winter where the "coolant low" light would pop on -- I swear I'm not stupid but I assumed it was because it was freezing cold and the engine coolant wasn't warmed up enough yet. I would monitor coolant temps and it never went above 190, but maybe that's what caused a crack somewhere. Once I filled up the coolant it went away, and I've still never had issues with coolant temps being too high.