Boost Leak....at turbo?

[thomastollar]

boost has been very sluggish lately. I do not have a gauge so am not sure what the boost is precisely, but decided to do test for a leak. After pressurizing the system (pcv line plugged and oil cap off) the leak is coming from under the turbo...could it be blown or something loose...? The turbo is a frankenturbo with less than 5000 on it. I have not taken the turbo off yet to check anything, and after some googling I did not find much. Thought I would give this a try as I do not have any experience with checking the boost.

[old guy]

If it's coming from underneath the turbo it's probably the boost hose from the turbo to the front clip. Either loose or cracked. I doubt it is the turbo.

[thomastollar]

OG, thanks....appreciate the advice as always. I know its not much to go off of right now, but I wanted to throw this up here partly to ease my mind and partly to see if it rang any bells. I am going to pull the turbo tomorrow and have a look, but I do not think its the boost hose, but hopefully you are right. Im pretty sure the leak is coming from where the turbine housing marries the compressor housing. I will update asap.

[thomastollar]

OG you were right. I must have been feeling residual air coming up from the boost hose. For the rest of the morning I played chase the boost leak moving from place to place tightening and adjusting. Will definitely be ordering a boost gauge this afternoon.

[old guy]

I am going to assume that you used the T-clamp that came with the F21L kit. I replaced it with an OEM clamp. I found that the t-clamp was just slightly too wide for the turbo lip and consequently it kept popping off. The narrower OEM clamp seemed to hold better.

[MetalMan]

I am going to assume that you used the T-clamp that came with the F21L kit. I replaced it with an OEM clamp. I found that the t-clamp was just slightly too wide for the turbo lip and consequently it kept popping off. The narrower OEM clamp seemed to hold better.

I use narrower clamps for pretty much ALL boost lines. T-bolt clamps are simply too wide to effectively pinch hoses / silicone couplers in many cases.
There are clamps called ABA clamps, they're made in Sweden and are awesome... they have a totally smooth inside and rolled edges, so they won't cut into hoses. They're worm drive but the mechanism is very stout.