Can't seem to pin point the problem

[DSM BoosT]

So I swapped out my evo3 manifold for a FP manifold and that's when everything started to go bad.... The first start up was a little rough but it eventually idled out and was fine. A week went by and I started noticing the idle getting rougher only when it was in neutral. When I first started the car in the morning it would idle around 200-400 and stall out if I didn't give it gas but driving it was fine, held boost, ran smooth, no noises and my log seemed fine. The idle became really bad and I decided to figure out what the problem was. I did a lot of research and decided to replace my Idle air control sensor. Before that I check all piping for boost leaks and found none. Well today I installed the new sensor and started her up. it still was a low idle but didn't stall out this time, so I adjusted the BISS screw so that the idle sat around 900. I went to go see if driving it had changed, when I did I notice when I got into boost I heard a loud scream (kinda like a supercharger) (wasn't the normal turbo or bov sound) so I stop and pulled over, It sat and idled fine however I notice that it sounded like a tire letting air out by the intake manifold, like really loud hissing. I check my turbo for shaft play and there was none and the blades are fine. Also when Im driving my rpm needle is wack and bounces around even when i'm not giving it gas....???WTF IS WRONG I have a video if someone could help me out..... also checked the timing marks and they are lined up

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[LOLVTEC]

Do another boost leak test. Your video does not play.

 

[getlikeme]

if your hearing air like a tire lossing air could be your intake gasket sucking air which would make it idle wrong

 

[LiquidX]

Your post is very hard to read.

I saw you changed out your exhaust manifold. Verify that you have no exhaust leaks. That means, physically get in there and look around for soot or exhaust fumes blowing a piece of paper as it idles.

Air rushing sound? Do a boost leak test with soapy water and look for bubbles. You should fill to 10 psi higher than what you are currently running. It should hold for a couple minutes pending your valves are closed, this test is should be started at the throttle body elbow.

 

[95'RS-T]

At one point in your video it looks like your stock boost gauge goes up when you slow down. How does your other boost gauge look? Does it reach your set boost limit? I can hear an exhaust leak when your under the hood. That air rushing, sounds like you have a bad/disconnected vac line, which would explain the idle if one was off.

 

[DSM BoosT]

At one point in your video it looks like your stock boost gauge goes up when you slow down. How does your other boost gauge look? Does it reach your set boost limit? I can hear an exhaust leak when your under the hood. That air rushing, sounds like you have a bad/disconnected vac line, which would explain the idle if one was off.

Stock boost gauge is set for coolant temp, and I checked all vacuum lines, there isn't any disconnected.

 

[LiquidX]

There are more than vacuum lines and did you do the proper boost leak test I posted?

 

[95'RS-T]

I agree with Liquidx perform the boost leak test on the throttlebody.

 

[NHerron]

Nice gauges

At the end of video, it really does sound like a good sized leak which a BLT should find with soapy water. If you can get a jack and some jack stands, you can get under the car and spray the bottom of the intake manifold if you can't find any other leaks.

It also sounds like you have a pre-turbo exhaust leak. Buy a can of Seafoam, draw in a 1/3 of the can via a vacuum line and shut the car off quickly after that. Let it sit for 15+ minutes and start it back up. It will be a crazy smoke show for a bit but you're sure to find any exhaust leaks that way.

 

[DSM BoosT]

Nice gauges

At the end of video, it really does sound like a good sized leak which a BLT should find with soapy water. If you can get a jack and some jack stands, you can get under the car and spray the bottom of the intake manifold if you can't find any other leaks.

It also sounds like you have a pre-turbo exhaust leak. Buy a can of Seafoam, draw in a 1/3 of the can via a vacuum line and shut the car off quickly after that. Let it sit for 15+ minutes and start it back up. It will be a crazy smoke show for a bit but you're sure to find any exhaust leaks that way.

I will try this tomorrow, thanks

 

[LOLVTEC]

Just do a boost leak test w/ soapy spray bottle.

 

[DSM BoosT]

I did a boost leak test and found my intake manifold gasket was blown by cylinder one port

 

[LOLVTEC]

Well there you go fix it. That should fix your problems.