performed boost leak... don't know how to fix

[AlaskanDsm]

So I finally got all the thing i needed to build a BLT device. Thanks to ace hardware... I only made one stop. So after I got everything put together, I pulled off my intake accordion and there was oil residue in there...woooo.... But I pressurized the system and my boost gauge slowly went up to ~6PSI where it stayed based on a leak that is coming from the Intake manifold. I poured a cup of dish soap and water mix on different places of the manifold while under pressure and found where it was leaking based on a sound change. From what i can tell... the area that the throttle cable connects to through the manifold is the culprit of a LOT of leaking air. I don' know how to fix that portion. I was hoping a hose. haha. But I also checked my turbo's shaft play and there was no play. So anyways if anyone has come across this before or knows how to fix it I would really appreciate it. Thanks.

 

[My1GLaser]

Throttle body shaft seals. Right behind the throttle cable there is a shaft that goes thru the throttle body to the other side behind the TPS. The seals get brittle with age and leak like a SOB. Check vfaq.com> DSM modification site> intake> TB shaft seal replacement. I can verify that NAPA can get the seals for about $15 shipped. I have gotten them from KamanDirect also, but NAPA was easier.

 

[ROOKIE1]

Throttle Body O-Ring

 

[AlaskanDsm]

thank you!! I will check with napa tomorrow or even tonight if i can get there. The VFAQ says sears or some hardware stores have them. I will have to check into it also does anyone know how hard it is to do this? looks like it would take about an hour or two.

 

[kenamond]

Next time you test, pick up a spray bottle from the grocery store or hardware store. Mix in a nice soapy solution of water and dish soap. Then you can spritz different areas including under things. Pouring isn't a very good method.

Before you pull the TB to fix the shaft seals, keep testing. You might fix that leak, get new TB gaskets, then find that you have to pull the TB again for a different leak. Try to find as many leaks as you can before you tear anything apart. Then you can fix multiple things at once. I'd bet you have other leaks if your TB shaft seals are leaking. Injector insulators (where the injectors "plug" into the head) are probably leaking, too. Get a flashlight, stick your head up over the fuel rail and find where the injectors plug into the head, nail them with soapy water, pressurize, and see if bubbles start to form around the injectors. Also, check your BISS o-ring. If it's bad, get a #5 o-ring from a hardware store for a few nickles.

Check your PCV valve, too. If that's leaking badly, you won't be able to pressurize very much. It's not technically a boost leak if your VC breather is still routed to the intake pipe, but a bad PCV can overpressurize your crank case (you boost your crankcase) and makes boost leak tests a pain. Get an OEM PCV if you have to replace it; Autozone/Carquest *will not hold boost at all*.

Oh, and that oil in your intake pipe is normal. The VC breather carries a bit of oil back to the intake pipe. You can get an in-line catch can or a fuel filter to catch the oil. It coats the inside of the entire intake which decreases performance particularly in the intercooler. If you've never cleaned your intercooler, I'd recommend it if you also install some can to stop future oil.

 

[AlaskanDsm]

Next time you test, pick up a spray bottle from the grocery store or hardware store. Mix in a nice soapy solution of water and dish soap. Then you can spritz different areas including under things. Pouring isn't a very good method.

Before you pull the TB to fix the shaft seals, keep testing. You might fix that leak, get new TB gaskets, then find that you have to pull the TB again for a different leak. Try to find as many leaks as you can before you tear anything apart. Then you can fix multiple things at once. I'd bet you have other leaks if your TB shaft seals are leaking. Injector insulators (where the injectors "plug" into the head) are probably leaking, too. Get a flashlight, stick your head up over the fuel rail and find where the injectors plug into the head, nail them with soapy water, pressurize, and see if bubbles start to form around the injectors. Also, check your BISS o-ring. If it's bad, get a #5 o-ring from a hardware store for a few nickles.

Check your PCV valve, too. If that's leaking badly, you won't be able to pressurize very much. It's not technically a boost leak if your VC breather is still routed to the intake pipe, but a bad PCV can overpressurize your crank case (you boost your crankcase) and makes boost leak tests a pain. Get an OEM PCV if you have to replace it; Autozone/Carquest *will not hold boost at all*.

Oh, and that oil in your intake pipe is normal. The VC breather carries a bit of oil back to the intake pipe. You can get an in-line catch can or a fuel filter to catch the oil. It coats the inside of the entire intake which decreases performance particularly in the intercooler. If you've never cleaned your intercooler, I'd recommend it if you also install some can to stop future oil.

Kenmond.... You are my hero haha. I finally got around the the BLT though!!! Anyways, I really need to get a spray bottle. I want to keep checking places before I even attempt to do the throttle body. I am sure I am leaking in a few places but that seems to be the loudest at 6PSI. I know that pouring isn't a great idea but its what i had to work with at the time. Anyways how can I check if i have a bad PVC valve? i'll do a search too. I should really get a catch can... when you punch the gas, the exhaust looks like it burns oil.... *sigh*. Oh and Kenamond, if you have pulled apart the TB, 1) is it hard and 2) VFAQ says #7 o-rings. Could you let me know if thats correct? Thanks for the info!!

 

[kenamond]

Kenmond.... You are my hero haha. I finally got around the the BLT though!!! Anyways, I really need to get a spray bottle. I want to keep checking places before I even attempt to do the throttle body. I am sure I am leaking in a few places but that seems to be the loudest at 6PSI. I know that pouring isn't a great idea but its what i had to work with at the time. Anyways how can I check if i have a bad PVC valve? i'll do a search too. I should really get a catch can... when you punch the gas, the exhaust looks like it burns oil.... *sigh*. Oh and Kenamond, if you have pulled apart the TB, 1) is it hard and 2) VFAQ says #7 o-rings. Could you let me know if thats correct? Thanks for the info!!

The PCV valve unscrews from the VC (it's on the back-passenger-side of the VC). I think it's a 14mm, but not positive. Unscrew it and do a BLT. If air leaks out of the bronze tube/tip of the PCV valve (the part that was inside the VC), you need a new one. If it's leaking badly, leave it out of the VC and hold your thumb over it and repeat the BLT. That will temporarily hide the PCV leak so that you can more easily search for others. When you put the PCV back in, don't overtorque it. That VC's aluminum, and you don't want to strip those threads. It just has to be able to seal and not vibrate loose, so it doesn't need too much torque.

My car must be new enough that I don't have TB shaft seal leaks yet, so I've never torn the TB apart. I've read the vfaq article a few times, but that's it. I'd pick up whatever o-ring they recommend; they're *really* cheap. I'd imagine someone would've had them fix the site if they mentioned the wrong o-ring size.

As for the burning oil, check your turbo for shaft play and do a compression test. The oil can be coming from the turbo, rings, or valve stem seals. If it's happening under boost, I'd suspect the turbo. Compression test will tell you if it's rings. Boost leak test can tell you about intake valve stem seals, but since you see smoke under load, I doubt that's the culprit.

 

[AlaskanDsm]

Well I sure hope its not the rings. My engine only has 4000 miles on it and I have been taking car of it pretty good!! Also I had my head rebuilt so I REALLY hope its not any of the seals. But I checked the turbo for shaft play today and I have none. But its a 14b that has unknown mileage, so it could be the turbo. But I get enough oil through the breather And probably enough in the intercooler that I might just need a good cleaning. I would also have to buy th tools for the compression test. Also I think I need a new VC and new seals...mine leaks and has broken bolt holes on it. *sigh*. But really thanks for the info.

 

[kenamond]

Well I sure hope its not the rings. My engine only has 4000 miles on it and I have been taking car of it pretty good!! Also I had my head rebuilt so I REALLY hope its not any of the seals. But I checked the turbo for shaft play today and I have none. But its a 14b that has unknown mileage, so it could be the turbo. But I get enough oil through the breather And probably enough in the intercooler that I might just need a good cleaning. I would also have to buy th tools for the compression test. Also I think I need a new VC and new seals...mine leaks and has broken bolt holes on it. *sigh*. But really thanks for the info.

The turbo can leak oil out of either the turbine or compressor side. If it's leaking out the compressor seal, you can test it.

Clean out the LICP and as much of the j-pipe as you can and disconnect the VC breather from the intake pipe. The car might idle badly with the VC breather off. Do a test run at full boost. Pull the LICP off the j-pipe and check for fresh oil. I've heard this and recommended it many times, but I've never done it (my T25 grenaded, so it was obviously a turbo issue for me). The one thing that might happen is that the oil that's still in the intake pipe may get slurped through the turbo and show up in the LICP even though it didn't come from the turbo, but I have no idea how unlikely that is. You could clean your intake pipe when you clean the LICP to keep this from happening, but I don't know if it's necessary to diagnose a bad compressor seal. When you're all done with the testing, put the VC breather back on the intake pipe nipple.

You can also test the turbine seal leak, but it's harder. You have to check that there's oil in the DP inlet (3 bolts to disconnect the DP from the O2 housing) but not in the exhaust manifold (which would mean the oil is coming from the turbine). That means either disconnecting the exhaust manifold from the head or the turbine housing.

Shaft play has nothing to do with the compressor seal as I understand it (it's wear in the thrust bearing which is different than a seal), so I'm under the impression that a seal could blow with no in-out shaft play. I'm not as sure about the turbine side. I believe the compressor seal is a big rubber o-ring (between the CHRA and the compressor housing) and a metal seal (around the shaft), but the turbine side is just a metal seal (way too hot for a rubber o-ring).

The other possibility (I'm guessing) might be a shot PCV which is leading to excess oil passing through the VC breather hose.

Heh...so the moral of the story is to check all sorts of crap until you figure it out.

 

[AlaskanDsm]

wow... I really have my day worked out for me tomorrow! Well If I want to do any of that should I buy new gaskets to put on? And it would really help to have access to someone like you for knowledge. I plan on starting with the BLT. I already went to the store and bought a spray bottle. And then I can mess with cleaning things out... especially the intercooler. And I can try that test. I will post back resutls tomorrow for sure. Thanks for all the information!!!! I'm hoping you might be on tomorrow so I can ask some questions then too. haha.

 

[ROOKIE1]

If you are mechanically inclined at all it isn't that hard . The hardest or most difficult part is removing the screws that hold the throttle plate in . Do not drop the plate once you get it out , it will bend if it lands wrong , don't ask me how I know .

Also make sure that you mark the spring on the side before you remove it . I used a large sharpy marker . Make the line straight and wide . This way when you put it back together you can be sure it is lined up correctly .

Most important is to take your time . Clean it up , watch/becareful with the sensors .

 

[AlaskanDsm]

I am pretty mechanically inclined...not say to be a mechanic but enough to keep up with my car. I did rebuild my engine with the help of my dad twice in a year.... thats another story.

Anyways I did the BLT again today trying to find other ares of leaking. I test my PVC and it is still good. But where as that still good 3 out of 4 of my injector seals are deffinetly leaking and I believe thats why I can't build past 6PSI. Kenamond you were right haha. Now does anyone have a part numbernfor these little things? I am going to see if schucks has them. Bu napa probably does as well. Just need to get this thing in much better operating shape.

 

[tbonitz301]

Here this should help. Slowboy Racing :: DSM :: Do It Yourself Parts :: Gaskets :: Lower Injector Seals

 

[AlaskanDsm]

I went to order from slowboy but when i went to checkout I would get raped for shipped.... So i'll just check with napa first and see how mucht hey can get me their 4 part piece shipped here. Thanks anyways tbonitz.

 

[AlaskanDsm]

Ok well after ome searching in town and no one having them I finally checked with the dealer and they actually had it cheaper than anyone in town, including slowboy. 25 bucks for 4 lower seals and 4 o-rings. Well after installing all that, I did another BLT and built up to 15PSI (could have gone further) and the only place left I was leaking was the TB shaft seals. But as its not worth my while to fix that because I am moving soon and storing the car. But I am still having issues with my idle being really bad when the car is warm and started back up. It dowsn't want to stay running and if you give it gas to keep it running it has to slowly search for its idle until it finds it. outside of that the car runs perfectly fine! I'm just lost.

 

[ROOKIE1]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge) , TPS Adjustment , http://vfaq.com/mods/BISS-1G.html , DmTaLoN's Idle Speed Control Test/Fix Page!