Thread: Vac loss, Power loss, strange bov whistle..WTF!

I checked it by blowing through the ends. You can only blow through the one side so im assuming its kosher.

I had a similar problem but like some of the other motor blew before i could find the source. Mine was shooting oil out the valve cover. Believe compression was my problem. Started off not that bad and got worse every day. From the 1st day of being boosted hitting my brakes would drop idle 2 or 300 rpm.

My car did the very same thing, but I noticed that it was because I had a line running from my intercooler piping to my valvecover. OOPS!!!!

I think that may have screwed up my PCV valve, so I plan on checking into that when I get home. Either way, new motor build, so I don't really care anymore.

Pinch the PCV hose and see if your idle goes up, if it does you have a vac leak. You could also try plugging both ends of the PCV valve and see if your idle/vac gets better. Dont run it for too long with it plugged though because you could have leakage in your piston rings causing massive vac loss.

while we are on the subject i have a strange almost high pitched police siren type noise coming from around my turbo area could it be the internal wastegate?? the valve inside or just leaky intercooler piping what do you guys think???
O yeah when i disconnect my MBC my boost gauge reads 5 psi instead of 7 psi so its most likely the internal wastegate???

Checked the compression today and it read 150 across the board. Checked if the timing chain skipped a tooth and it was good to go. Removed and MBC checked, no change, re-installed. Took it for a drive and the vac is back at 18-19 No idea why or how but it seems to be back on target. I noticed the constant whistle from the bov is gone now aswell. I wish I could tell you what it was but it seems my prayers were answered and the dumb thing fixed itself

Hey......maybe a spark plug was loose? Just a thought...or there could have been a leak in the valve cover gasket....