potent951turbo

Ok so after my post about having zero power and zero boost everyone seemed to think it was a clogged catalytic convertor so I pulled out the cat. and gutted out everything. I put the cat. back in and went for a drive and with the wastegate line totally pinched off I am getting 8-9 psi (4psi with the line open), but its still not very healthy because you really have to floor the car hard and get up to about 4-5k rpm to get that much boost. I have run through my vacuum lines several times and they are all connected properly. And the car still seems to be a bit weak on just normal power. Before I had any problems I could easily get 15+ psi barely trying. What should I check now?

hosrom_951

Take off the intake cowl (j-boot, MAP/MAF filter, what ever you have) and take a look at the turbocharger, look for bad fan blades.

I suspect a major leak in the exhaust system since you have zero power before messing with the exhaust, and now you are getting more.

Chas

Major leak in the crossover?

Ian Carr

Sounds like your turbo is going. That or a major leak in the exhaust before the turbo. Can't think of much else

-Ian

Dal Heger

Did you double check the exhaust pipe that goes from the turbo to the cat? That is a typical failure point. It collapses between the turbo and the cat, pinches off the exhaust and increases backpressure to a HUGE amount.

Just a thought.

Other than that, it could be a bad wastegate (cracked seat) or bad turbo.

Good luck!

Dal.

potent951turbo

I have checked the blades on the turbo and they look perfect and the inside is very clean. I am not getting any smoking or excessive oil consumption. I know I do have a few exhaust leaks, which is the next project to check out. Is there anything else I should check?

Ian Carr

The headers are known to crack. If you have the heat shield on then its hard to find out

aixgelo78

why dont you pressure test the whole piping system from the turbo to the throtle body sound like you have a boost leak. I might be wrong but if it was a major exhaust leak, wouldnt you hear it, wouldnt your eyes tear everytime you look in your engine bay when the car is on. I always found that a broken hose was a problem when I did not get the right boost level in my old car.

good luck chris

Eyal 951

sounds like wg to me, dunno why people don't think it is, maybe I missed something in a previous thread.
~Eyal

PorscheDoc

Clamping the line off to the wastegate would give more than 8-9psi boost if it was a wastegate problem.

Jason_86_951

Not if the spring inside was toast, or if the valve is not seating properly.

Get a quiet air source and apply 5-7psi slowly to hear the WG open, then let the air go quickly to hear if the WG slams shut.
The WG could be (pun intended) wasted.
Cheers,
J

Dr. Dynamics

Any sounds different than normal?
Can you hear the turbo spooling up like usual?
If it does, you could have a leak on a vaccum line and the turbo is trying to give you the boost but just throws it away. Try spraying some water with a clean degreaser bottle around all possible leakage areas during idle to see if the car will try to stall.

If you can't hear the turbo spooling up like usual, J's probably right since all the gases would be bypassing the turbo...

potent951turbo

Before I gutted the cat it seemed my turbo spooling sound and basically died and totally gone away. And now that I have gutted the cat it is back like it was before but I am just not getting the boost I use to get. I am definately going to be replacing all the exhaust sealing areas and checking for cracks etc.. I had the wastegate off a few weeks ago and it seemed ok and visual inspection but I will need to check that again more properly.

Jason_86_951

Just a thought, are you sure that you got everything out of the cat?
Maybe some of it got shoved up into the bend where it's difficult to see.

potent951turbo

Yeah I made sure I got it all out, I even used my high powered blower after pushing some flexible rods through it.