Howling Noise...No, not a warewolf.

[Mist3r Spool]

I jump on the freeway after about a half day of driving and noticed a howling noise coming from my intake side of the engine. It didn't ever happen before so I was kinda worried I had a new leak or something. The thing is, my car is running fine. I was thinking my air filter is loose or I have a TB leak, but I dont. I can only hear it under boost. Any ideas?

 

[justin0469]

if you had some type of air leak, it would probably be noticeable. do you have an aftermarket boost gauge? if so, is vaccum and boost levels the same as before?

 

[Mist3r Spool]

if you had some type of air leak, it would probably be noticeable. do you have an aftermarket boost gauge? if so, is vaccum and boost levels the same as before?

Have an aftermarket boost gauge. It reads 20" of vacuum and when I boost, it steadily holds 20PSI. One odd thing, however, when I first turn on my car and I'm idling, the vacuum is only 10"-12" then after driving, it'll return to 20" of vacuum. It appears to be the FPR solenoid is bleeding itself from the cap. The hole on the FPR solenoid is so small that I doubt it could product that type of noise. Should I just cap off the FPR solenoid? Is it supposed to hiss like that?

 

[justin0469]

if you mean the FPR at the end of the fuel rail, no you cannot cap off that vacuum line. since you hear this mostly under boost, make yourself a boost leak tester and go at it

 

[Mist3r Spool]

I've searched around the web and found some info from a place called Taboo Racing (or something) and they have some info on removing the FPR solenoid. I think that'll remedy my vacuum issue. It's pretty interesting info, check it out:

http://dsmtuners.com/forums/showthread.php?t=198327&highlight=solenoid+removal

 

[justin0469]

thats EGR not FPR. like i said, you cant remove your FPR vacuum line

 

[Mist3r Spool]

thats EGR not FPR. like i said, you cant remove your FPR vacuum line

I'm talking about the FPR solenoid. The link does refer to it:

..."The fuel pressure solenoid can be safely removed. Its function is to increase the fuel pressure on start-up by closing the vacuum path to the fuel pressure regulator which is suppose to prevent the fuel from evaporating when the engne is hot. This is not a problem when high volume fuel pump is being used or might take just a bit more cranking in case of completely stock fuel system."

Anyway, I removed the solenoid and just "T" tapped in the boost gauge and the vacuum reading at idle has been cured. It's 20" every time now. Also, the rough idle I was facing has been remedied as well. Apparently, the FPR solenoid isn't necessary after all, if anything, just another pain and possible place where a vacuum leak could occur.

 

[Mist3r Spool]

Ok, to get back on track to the subject, the noise is gone. I doubt that removing the FPR solenoid vacuum line did the trick but who knows. Thank you all for your feedback.