boost/vaccum leak HELP

[cumpersgsx]

I just installed my xs power fmic and when i gave it some boost i get a whining sound at higher rpms (3500ish)...when i rev it at idle it gives a little whine at about 6-7000 rpms. I also noticed that the oil line fitting to the turbo is leaking a little bit of oil. Would that make my turbo whine like that? I tried to do a boost leak test and it never even pressurized...so im lost. I've checked over everything and still nothing I swapped bovs (recirc) and still got nothing. On top of that i got a cel and dont have an obd ii diagnostic. So isn't the only cel they can really give in this situation the emissions code (for when people remove that stuff) and a vaccum leak? please help me with this guy i've been working on this for a while. Any help would be greatly appreciated

 

[91 Turbo Mitsu]

If you never pressurized the system I would think it would be a big boost leak.What did you use to pressurize the system.

 

[cumpersgsx]

If you never pressurized the system I would think it would be a big boost leak.What did you use to pressurize the system.

well the thing is that i tried to pressurize it. I hooked it up to the turbo inlet and using a bike air compressor. Nothing registered on my gauge at all.

 

[kenamond]

well the thing is that i tried to pressurize it. I hooked it up to the turbo inlet and using a bike air compressor. Nothing registered on my gauge at all.

Although I've heard of folks actually doing boost leak tests successfully with a bike pump, I don't think that they are much use unless you don't have any significant leaks. I recommend an air compressor or a portable air tank (fairly cheap at any hardware store). I have an 11 gallon tank that I charge to ~120psi at the local gas station and use for boost leak tests and tire pressure adjustments. I think it cost me about $60, but they rip you off in my town, so you could probably find a comparable one for cheaper.

Also, with your mods, I urge you to get a logger. For now, take it to Autozone to get the CEL read (for free). Knowing that might shed light on the problem.

So once you get around to a real boost leak test (not with a bike pump), you'll probably find out where the major leaks are. Remember to do the leak test on a warm motor. Also remember that a major boost leak will lead to you overworking your turbo which is not good. You need to look into this right away.

Did your turbo oil supply line leak before you installed the FMIC? I don't see why an FMIC upgrade would affect that. Depending on the turbo, these oil lines can be a royal pain to reach to tighten a bit. I was able to tighten my FPB28 with a crow's foot wrench and ratchet extensions.

The whine you hear might just be related to metal IC piping (if you upgraded from stock, rubber LICP). The turbo has a natural, very high frequency note, but I'd have to hear it to know if it was the normal turbo sound or something else.

Check for shaft play, as the ringing could also be the compressor vanes rubbing on the housing (hope not!).

Lot of stuff to look at. No definite solutions from me. Sorry.

 

[cumpersgsx]

i checked it for shaft play and everything seems fine. I only have about 2-3k miles on my 16g so its damn near brand new. I really dont think that the sound im hearing is normal. i have driven it like this for almost 200 miles. Ill definitly take it up to autozone though. Any other suggetions?

 

[boosted_91_tsi]

I just tested my Talon for boost leaks, Using a small compressor, I could not even build 2 PSI on the gauge. I had 2 injector seals leaking like crazy. I pulled it all and replaced the seals and did the test again. I got slightly higher pressure this time (3-4 psi) but i found my fuel pressure regulator is leaking like crazy. The compressor makes it easy because you can just plug it in and let it run while you hunt down the leaks. Just thought I would share where my problems are so you have something to check. Another way to do it is to hook up the tester directly to your throttle body elbow. If you get no leaks here then you can narrow it down to your piping.

 

[cumpersgsx]

well when i was using my compressor it was so loud i couldnt even check for the leaks. Looks like i have a lot of hunting to do. Any other experiences/advice anyone would like to share?

 

[cumpersgsx]

could i go to a do it yourself car wash and use the air compressor there?

 

[Gromit]

could i go to a do it yourself car wash and use the air compressor there?

I'm assuming you're talking about the air compressors for filling tires? If so, those have no way to regulate the pressure & you don't want to over-pressurize your system. You want to be able to control the pressure & pressurize your system to roughly the psi you plan to run, or slightly above.

If your compressor is too loud, try positioning it further away from the vehicle. Also, spray soapy water over everything & then you can see the leaks via the bubbles rather then having to rely on hearing them - even if you can hear a leak you can always pinpoint exactly where it's coming from.

 

[boosted_91_tsi]

Also, spray soapy water over everything & then you can see the leaks via the bubbles rather then having to rely on hearing them - even if you can hear a leak you can always pinpoint exactly where it's coming from.

That is how I found mine. It is a good idea to have someone in the car watching the boost gauge too. I plug my compressor into my cig lighter so I can watch the gauge while it pressurizes.

 

[cumpersgsx]

well my boost leak tester has a gauge right on it so it should be easy as just looking at it and pulling it off right? Does it lose pressure in the system fast or could i pull off the compressor hose at any time and still have pressure? My compressor at my house only has a 5 foot hose so theres not much i can really do to get it away from the car thats why i was thinking i could use one from a diy car wash type deal.

 

[cumpersgsx]

well in michigan the diy car wash places dont have air compressors...did anyone know that? I just went to like 4 places . So i ended up fixing my car at a gas station...wierd i know. I ended up having a leak from the elbow to the tb. With the xs power fmic its so hard to adjust the bottom nut on the tb without grinding that post. I have another leak right at the TPS sensor...is that normal? Its not from the biss screw. IT FINALLY PRESSURIZED. It pressurized to 5 lbs. Should i just jb weld the hell out of the tps sensor?

 

[kenamond]

I think you can let your compressor charge to say 100psi and then turn it down so that it won't kick back on while you do a few tests. Make sure you don't overpressurize your intake. It's good that your tester has the gauge right on it.

If you test on a warm motor and have decent compression, no intake valve seal leaks, and no boost leaks, you should be able to pressurize to 20psi, stop adding air, and leak down 1psi every second or two. If you're running higher boost, add 5psi to your target boost level for your leak tests.

There are finer details to doing the test right when you've gotten down to the tiny leaks, and I recommend you search for more information about that. For now, you don't have to be so picky, as you may still have some fairly major leaks. When you get to the point that you can actually pressurize to 20psi and have it not leak down in 2-3 seconds, you should start blocking off other known leaks like your MBC or BCS.

I'm not positive about the TPS leak, but the throttle shaft seals are known to be a common location for boost leaks. Mine doesn't leak, so I don't have first-hand experience. Again, search around a bit, and you'll surely find out if that's the shaft seals leaking - but that's my guess.

If you have major leaks, bubbles may not form, so the soapy water spray bottle may not find them. If you can shut your compressor up during the test, you can hear the leaks.

Good luck!

 

[cumpersgsx]

i think im going to get my tb rebuilt so i think ill be going with these guys http://www.throttlebodys.com/ after that maybe ill be able to pressurize to at least 10 lbs ...Good idea guys?

 

[boosted_91_tsi]

I may be wrong but isn't the 1G TB an upgrade for the 2G, or am I thinking of something else? If you are pulling it off to have it rebuilt, why not upgrade?

 

[cumpersgsx]

i dont know exactly how to swap them and dont want to deal with modifying anything . If anything can go wrong it will with me. It does.

 

[boosted_91_tsi]

http://www.roadraceengineering.com/2gtbswap.htm

That is what I was looking for. It is a little bit of work and I do understand your point of not wanting to do it, . I have those moments too where I am just like "Throw another stock piece on there and be done with it!" Good luck to you whatever you decide.

 

[cumpersgsx]

http://www.roadraceengineering.com/2gtbswap.htm

That is what I was looking for. It is a little bit of work and I do understand your point of not wanting to do it, . I have those moments too where I am just like "Throw another stock piece on there and be done with it!" Good luck to you whatever you decide.

I dont feel like such a lazy ass now. Good to know there are some people like me out there.

 

[cumpersgsx]

just a little update...

-i fixed the tb elbow to the tb (or at least i thought i did) tested it and it pressurized to about 5psi, then i
-found another leak at the tps sensor...so i jb welded the #### out out of it, tested again, got about 7-8 psi.
-Then found another leak at the j pipe...fixed that one. Tested again got up to about 10-11 psi.
-Found that the tb elbow to the tb was still leaking so i took off the eblow and killed it with gasket sealer/maker. tested again and got it to 14-15 psi and my tester blew apart


Is this an ongoing thing to constanly mess with boost leaks?