Boost leak test, bad turbo seals? air coming out of dipstick?

[dragrush]

I did a boost leak test on my turbo inlet and I hear bubbling when I take the oil cap off. I then tested it at the licp, the bubbling stops but there still is air coming out of the oil cap and dipstick. I blocked off the pvc valve, and got same results. Compression test shows 170 171 172 171. I dont build boost while driving. No bubbles in the coolant. Im guessing the turbo seals are bad. Will the air coming out of the dipstick and oil cap be due to bad valve seals? What does this sound like it can be? Help appreciated

 

[SoonToBeDSM06]

Yes if it still comes out of the oil cap when you put the tester after the turbo it probably is your valve seals. Because the PCV valve is a big boost leak sometimes and I finally got fed up with the PCV valve all together when I bought 5 of them from the dealer and they were all bad. So it very well could be your valve seals. Check the shaft play on your turbo it see if there is any in and out play.

 

[oldman]

What SoonToBeDSM06 is trying to say is : Move the leak tester to the TB elbow and see if hissing/bubbling stops.

 

[dragrush]

Yes the turbo does have shaft play side to side, but not in and out. And the bubbling stops when I hook up the boost leak tester to the TB elbow, so Im guessing the turbo needs some work done to it. But is weird that my valve seals are bad already, I only have 100 miles on my engine

 

[dragrush]

Also there is no kind of smoke coming out of my exhaust or turbo, and no oil in my IC pipes.

 

[oldman]

so Im guessing the turbo needs some work done to it.

It's normal for air to pass through the seal during a static pressure test due to the lack of oil pressure as long as it's not leaking during operation, smoking out of exhaust.

the bubbling stops when I hook up the boost leak tester to the TB elbow

How about air out of oil cap?

Telling us what led you to the boost leak test might be helpful.

 

[dragrush]

When I hook up the boost leak tester to the throttle body I hear air coming out of the dipstick and the oil cap (when i take it off). Here is a link to the reason why I am doing this, supposly AMS said they did a boost leak test and it was fine. Having the same problem after I took it to them, I decided to do a boost leak test myself. Obviously they didn;t do it. http://dsmtuners.com/forums/showthread.php?t=193224
I currently have the t04b 60 trim.

 

[dragrush]

Also fyi for the link above, I have this 60 trim on now and it only builds 5psi and then flutters to 0.

 

[oldman]

So the car isn't smoking, to4b 60 trim surging and only boosting 5psi? Any other problems you want to add?

1. What BOV? Did you try adjusting it?

2. Was the turbo boosting 5psi from day one?

When I hook up the boost leak tester to the throttle body I hear air coming out of the dipstick and the oil cap (when i take it off).

Turbo inlet test => hissing and bubbling TB test => Hissing only
Is this right?

 

[dragrush]

So the car isn't smoking, to4b 60 trim surging and only boosting 5psi? Any other problems you want to add?

1. What BOV? Did you try adjusting it?

2. Was the turbo boosting 5psi from day one?


Turbo inlet test => hissing and bubbling TB test => Hissing only
Is this right?

I have the blitz BOV, tried adjusting it every possible setting tightest to losest

Yes the to4b 60 trim was boosting only to 5psi from when i put it on, but the to4b h-3 which i had on prior to the 60 trim got to 19psi but then fluttered down to 0 with compression surge

And yes turbo inlet test= hissing and bubbling
TB test= hissing from oil cap and dipstick w/out bubbling

 

[oldman]

Yes the to4b 60 trim was boosting only to 5psi from when i put it on, but the to4b h-3 which i had on prior to the 60 trim got to 19psi but then fluttered down to 0 with compression surge

Did the car ever blow smoke out of exhaust? Losing oil?

And yes turbo inlet test= hissing and bubbling

Disconnect the pcv hose from the intake and cap off the nipple, repeat pressure test at the TB.

 

[dragrush]

Did the car ever blow smoke out of exhaust? Losing oil?



Disconnect the pcv hose from the intake and cap off the nipple, repeat pressure test at the TB.

It is not and never had blown smoke out of exhaust, not even between shifts or start up. I cant tell if i am burning oil from oil levels due to a bad oil leak.

Already tried blocking pcv hose, and attach tester to TB, still had same results

 

[oldman]

How much pressure was it holding at the TB before and after the pcv block off? Are you sure hissing was coming from the oil cap only?

 

[dragrush]

How much pressure was it holding at the TB before and after the pcv block off? Are you sure hissing was coming from the oil cap only?

I brought it up to 20psi and the pressure drops to almost 1-2psi in about 5-10 sec. My tb has a slight leak at the biss screw, but I dont not have a new o ring for it yet, so that will let it drop faster. The pressure seems to hold about the same with the pcv blocked and connected. If i take the oil cap off i hear air hissing and feel a breeze coming out of it, along with the dipstick.

 

[oldman]

If you have not repeat the pressure test at the turbo inlet, do so tomorrow and record the pressure level, this is also to make sure the TB elbow coupler isn't leaking after the TB test so we can rule out boost leak with 100% certainty. There are a lot to obsorb here, I'll think about it and respone tomorrow. It's almost past my badtime.

 

[dragrush]

Well i talked to AMS today and they said it was normal for air to come out of those places due to al the intake valves not being colsed and it was not normal for the the oil bubbling when the leak tester in connected to the turbo inlet. Does this sound correct?

 

[oldman]

Well i talked to AMS today and they said it was normal for air to come out of those places due to al the intake valves not being colsed

You don't leak air into the crankcase via intake valves, rather through valve seals and piston rings. Intake valves being open means air gets into the combustion chamber, not into the crankcase.

and it was not normal for the the oil bubbling when the leak tester in connected to the turbo inlet. Does this sound correct?

It's normal for air to pass through turbo seal during a static pressure test due to lack of oil pressure. This is why I kept asking you if it's leaking oil and blowing smoke. Why didn't AMS discover this when they did the pressure test anyway?



This is what I think,

1. TB test up to 20psi : Because you're not smoking at all, I think the valve seals are good. Some air is probably getting through your rings (a wet compression test will confirm this) but not too serious due to the fact that you're not smoking and able to pressure test up to 20psi.

2. Compressor surge: This is probably related to either the BOV (I know you have adjusted it) or turbo itself. If you do a search you'll see that there are some threads concerning t04b surge, v-trim and 60 trim in particular. The only way to make sure is to try a different BOV.

3. Turbo boosting and spool problem: Given that the pressure test is satisfactory (I still would like to know the pressure level at the turbo inlet), no major exhaust leaks before turbo, actuator arm attached and flapper fully closed, good compression numbers and the turbo only boosted 5 psi from day one, it's pretty clear that the problem is related to turbo/actuator. Let's do some tests to find out.

3A. Apply compressed air to the actuator to make sure it doesn't open before the spring rating. If it checks out, go to 2.

3B. Wire the flapper shut. If problem solved, exhaust gas is blowing the flapper open, pre-loading the actuator might help. If problem persists, it's the turbo itself.

 

[dragrush]

AMS told me they did a boost leak test, so I thought I was free of boost leaks until I tested it myself. My throttle body was leaking real bad so I replaced it with the 2g temporarely.

I used one of my buddies working Blitz BOV from his 240 and had no change in results.
Not sure if this is normal, but I when I put the boost leak tester at the licp my BOV doesn't open, but when I take the vac line off it opens at 20 psi (spring rating). I got up to about 25 psi with the vac line on and it stayed closed.

I also found out that the gauge on my boost leak tester is not very accurate, so I am now reading it from my boost gauge. When I hook it up the the turbo inlet 20 psi last about 10 seconds. And licp it takes about 30 sec for 20psi to drop to 0. Still air coming out of dipstick though....

I haven't done the wet compression test yet, my friend is borrowing the tester and haven't been able to get a hold of him. But from the looks of it, it looks like its time for a new turbo....again. What you think oldman?

 

[oldman]

Not sure if this is normal, but I when I put the boost leak tester at the licp my BOV doesn't open, but when I take the vac line off it opens at 20 psi (spring rating). I got up to about 25 psi with the vac line on and it stayed closed.

That is normal. Most BOV are design to be pulled open by vacum. When the vacuum line is on, there are equal pressure on both side of the valve so it stays closed as it should be, regarless the spring rating of your bov.

But from the looks of it, it looks like its time for a new turbo....again. What you think oldman?

I have suspected the turbo right from the start, with all these test results, you can now talk to the vendor with 100% certainty. Let us know what happen with that, good luck.

 

[dragrush]

UPDATE
Well I put a new turbo on.(RS49T) and I still have the same problem In between the swaps I towed it to AMS to do a leak down test and they came back good...9-10% leak down, they also did boost leak test and fixed only leak at the biss screw. They then told me it had to be the turbo once again, so I got a different turbo for the third time and still have same problem. But at least I can get it up to 10psi now instead of 5. Now I am really confused though what it can be. AMS does not even know whats wrong here I really don't know what to do. I need some suggestions please. What else can it possibly be?

No boost leak
Leak down test= 9-10%
3 different turbos...wont hold boost
Tuned by AMS
Timing is dead on
Tried different BOV. Vac line T into AFPR
All supporting mods

 

[oldman]

I'm sorry a replacement turbo didn't work out for you, seems like everything else has been covered. What does the car feel like when you go WOT? What's your logger telling you?

 

[dragrush]

I haven't gone WOT yet, the engine only has 200 mi on it so I'm still breaking it in. I went go about 3/4 throttle and bring it to about 5500 rpms. As i accelerate it drives smooth until the turbo starts to spool the car shakes a little and has a hard time accelerateting any more. On this 50 trim it gets to 10 psi and and then flutters down to 0. When i tap the gas at cruise I get 1-2 psi and then compression surge. Ill try to figure out how to post the logs from dsmlink on here to show you whats going on. I also have another appointment to AMS next wed for the 5th time now, their just going to start going over everything cause they have no idea what it can possibly be a either.

 

[psychlow]

Yes the to4b 60 trim was boosting only to 5psi from when i put it on, but the to4b h-3 which i had on prior to the 60 trim got to 19psi but then fluttered down to 0 with compression surge

This makes me wonder about your valvetrain.

If you haven't already, I'd pop off your valve cover and see if you have any misplaced (popped out) cam followers and inspect for collapsed lifters.

You shouldn't see surge at WOT. If you are, something is usually wrong - and it's not going to be caused by boost leaks.

 

[ddavisaf]

Don't forget about...

3A. Apply compressed air to the actuator to make sure it doesn't open before the spring rating. If it checks out, go to 2.

3B. Wire the flapper shut. If problem solved, exhaust gas is blowing the flapper open, pre-loading the actuator might help. If problem persists, it's the turbo itself.

And just to verify.... what are the results of your boost leak test again from both LICP and Throttle Body Elbow?

 

[dragrush]

The valve train is one of the only things I haven't looked at yet, and is the only thing really I can think of that may have something to do with this, Ill have AMS take a look at it this upcoming wed when i take it in and see if everything is the way it is supposed to be in there, cause I don't notice anything.

I also did boost leak test after the turbo install and it holds 25 psi for over a minute

I appreciate all the help and Ill stay updated