Understanding my boost leak problem.

[gfalbert]

My 1991 TSI lost all boost from the last time I ran the car (it ran fine until I turned it off) and then a few days later I started the car took off and the boost gauge didn't move. The car runs fine just no boost at all. I did take my compressor air gun and spray some tree leaves from the back of the intake manifold area since the time I shut it down and lost boost.

I hooked up the tester to the turbo inlet and barley got the boost gauge to move and it leaked out just about as fast as it went in.

I moved the tester up to the tb elbow and had the same results.

I have my compressor set to close to 30 psi to get my boost gauge to about 10 psi and would leak out in just two seconds as soon as I stop pumping air.

I sprayed down the engine area with soapy water and found the biss screw leaking and the two middle fuel injectors at the chamber side and a small one around my tee leading to the boost gauge. I changed the biss screw o-ring and put some silicone at the tee to stop those but haven't changed the fuel injector o-rings. (Due to a mix up with NAPA and a thread on here where the guy said he bought four sets of o-rings for $11.99 and that turned out to be for just one set so that's all I have right now)

I have my oil cap off and can hear the air coming out. I learned a lot about this from reading replys from Oldman but can't figure out my next steps. I did plug off the pcv but that didn't seem to make a differance. I saw no leaks around the intake gasket or hoses that run to the top of the tb. I didn't see any leaks around the egr but it is difficult to tell due to the location.

When I ran the car it still did not boost at all. Can you loose boost that fast from just the injectors leaking?

Compression check showed close to 150 on all cylinders.

My turbo has only a few miles on it and has no shaft play but how freely should the turbine spin? It doesn't take a lot of effort but you can't flick it and make it spin freely either.

 

[xveganxcowboyx]

Check to make sure your wastegate is working properly. If you can pump to 10 psi you shoud register at least SOME boost while driving.

 

[BOBS90TURBO]

Two leaking injectors will not cause a leak that bad, and yes your compressor wheel should turn with just a flick, like he said, You should check your waste gate, it may be sticking open.

 

[gfalbert]

I took my air gun and blew a little air into the actuator and the arm moves out and sucks itself back smothly but I guess I need to take off the o2 elbow to see if it is closing all the way.

I am also going to double check the compression test but you would think if I had that bad of leak by the pistons I would have some type of smoke but I don't. None on start and none when I run the car for extended periods.

 

[majik2k5]

I'd double check the BISS if I were you. I had one blow out of the throttle body on me, and when I put it back it in it didn't leak, but it still wouldn't push any boost. So I had a friend take a look at it and it turns out there's a certain way to adjust it to where it was. I'm not sure at all what he did, but he readjusted the BISS and it ran fine.

 

[oldman]

If the boost gauge reads vacuum during idle and reads boost during a pressure test, with good compression numbers, actuator arm properly attached and no obvious huge exhaust leaks, I can only think of two possibilities in which you get ZERO boost.

1. A huge boost leak between the turbo inlet and the TB elbow.

I hooked up the tester to the turbo inlet and barley got the boost gauge to move and it leaked out just about as fast as it went in.

I don't believe you ever went back to the turbo inlet after your 10psi TB test, perhaps you have a huge leak some where at the IC.

2. Dead turbo, you mentioned it does not spin freely but it turns. I suggest taking off the turbine side and make sure the turbine wheels are still intact.

 

[gfalbert]

Just letting everyone know what I ended up finding out and to say thanks for the help.

The turbo was bad, it didn't last more than a few hours. I sent it back to the place I bought it (g-pop shop - they were on e-bay and had 100%) and they rebuilt it and sent it back in a timely manner.

Guess what, the rebuilt one didn't last more than a few minutes and it totally seized up.

I put the stock one back on and the car runs like great. Not sure what to do about the other turbo and G-poop shop. Anyone else deal with them?

 

[olmytsi]

Buy turbos which alot of people run from reputable shops...gambling with unknown shops gets you this type of stuff.

Good luck

 

[RiceKiller_TSi]

Guess what, the rebuilt one didn't last more than a few minutes and it totally seized up.

They probably just reboxed the one you sent them. Tell me this wasn't one of those knock off EvoIII GT's.

Use it as a paper weight and buy a turbo from a reputable shop like said above.

 

[fourreGsixty3]

Wow, that sucks man, cant say Ive delt with them, seems that their products are like their shop name.Like said^^^get a turbo from a reputable company such as www.dsmparts.com, or www.hahnracecraft.com, or www.slowboyracing.com. All of those are very reliable and very helpful with customers.

 

[kwkdsm]

Have you contacted the store you got two turbos from, Im kinda interested in what they have to say about this. If iwas you I would get to the bottom of it and let them know you are not very happy. I can only imagine getting two new turbos and both of them being bad!!!

 

[erebusknight]

were they getting a good feed of oil I presume? No oil = Turbo Death...bleh
Im sure its ok

 

[gfalbert]

were they getting a good feed of oil I presume? No oil = Turbo Death...bleh
Im sure its ok

That's what I was thinking but what I can tell you is that I squirted oil in the feed line before I started it. Also after it stopped working, when I took the intake off there was oil inside the inlet. I don't know my oil pressue because I still have the stock gauge but after it warms up it appears somewhat low which seems to be the norm from what I have read on here.

I do believe I did a competent job putting them on but it does make you second guess yourself. Like I said so far the factory turbo is working fine and it has 100k on it.

I am running 5/30 weight oil maybe I need to run 10/40 with my miles? I'm not sure since it's been a constant 20 - 30 degrees aroud NW PA here lately.

 

[toffa]

What brand turbo was it? Mitsubishi (16G?)

 

[gfalbert]

What brand turbo was it? Mitsubishi (16G?)

No, it was a rebuilt 14b with a bullseye housing. I have a 1g auto so I was going to do a small upgrade since I don't have all the stage 1 mods yet.