Squealing Noise from EFI mustang HELP

stangnerd

stangnerd

Forum Member
I need help. I tried to put a PCV system on my 92 Mustang. The car was running a little bit rich, but it wasn't running too bad, but I thought I could get it to run a lil better........WRONG. I completed the PCV valve install and installed my system max II intake better then I did originally. Because I bought the system max II intake came from a blower car so the PCV area is welded closed. So I tried to run the PCV valve through the driver side valve cover and a breather on the passenger valve cover. Started the car up and Loud squealing noise! The noise itself sounds like it is coming from the passenger side of the engine. I have Tried everything I could have think of. Currently I have removed the PCV. The car is running two breathers through both valve covers. I have checked for any vacuum leaks, this is a T5 car and I serious doubt it is the through out bearing. The motor is a 347 with trick flow heads 30lbs inj 75mm mass air. Could I have cracked the intake when putting the upper back on or I don't I am stomped. I would be so grateful for any help Thanks
 
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If you think you might have a vacuum leak spray the area with carb cleaner. If the engine surges, you found your leak.
 
I have been researching the crap out of this on Yellowbullet, corral, and here. I have tried carb cleaner, I have ran the car with out the belt on, never touch the distributor, T5 always ran good and shifts great. After a few hours of thinking and researching I believe it is a vacuum leak from the throttle body. I did remove the throttle body and upper intake to get to driverside valve cover. I prob miss it with the carb cleaner LOL.Will have to try it tomorrow if this is it I will be so very happy. And hopefully this thread will help someone else out in the future ;)
 
Im confused . Is the noise still present with the Pcv taken back off? I have seen people use nonvacuum hose for Pcv and brake booster. With normal hose the vacuum will suck the hose closed and cause a loud whistle
 
Yes the noise is still there even with the PCV valve completely removed. I sprayed carb cleaner around the vacuum tee and no surging or change in rpm. I read some dude had a similar problem on corral and it was from a torn throttle body gasket.
 
Can i ask the ultimate ?? Why add PCV valve, it's a large unmetered vacuum leak? I've eliminated them on every performance motor i've ever had.

As far as the noise, check for the torn gasket, and also clean the IAC valve, make sure something isn't lodged in there.
 
what kind of breathers on the valve covers? possibly pressurizing problem if it is a whistle or moan
 
I would 2nd throttle body issue as well or IAC. Does it change with rpm, is it a sqeal or more of a loud whistle?
 
don't know if this helps but on my 02 gt it whistled so i cleaned the iac and it still continued to whistle so i replaced it with a new one and its gone !!
 
I may be wrong but ive seen 5.0's that have tall valve covers and an aftermarket intake, where if you dont use a tall enough intake spacer, the intake will hit the valve cover and not allow it to fully seat properly when tightened down, causing a vacuum leak...?? Check that.
 
I thought it wouldn't hurt to add a PCV valve system Boy was I wrong. The noise sounds like it could be coming from the Distributor which puzzles me because I did even touch it. The car is now running richer than ever. I did change throttle body gaskets and no change. I hoping that this is something small and nothing too major. I truly appreciate replies and input...many thanks.
 
The valve cover that are on the engine are trick flows but are not tall just enough to clear the roller rockers.
 
One is a motorsport enclose breather and the other is a small pepboys open breather. I am going to try to post pics. I am sure that would help
 
and you are sure its not a oil starvation issue. like a clogged journal at a cam or main bearing?

just throwing that out there.

he is a trick though, get a stethascope, remove the end so its just a hose with nothing on the end (oposite of your ears) and run the hose along the leak areas listen for a whistle noise. itll help narrow it down even further.
 
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