14b Will not spool.

[bartels903]

My 14b will not spool anymore, I was driving down the road holding 13psi for about 10 seconds and then it just suddenly dropped to -20. I can't figure if something is wrong, or I just blew it?

 

[MrBoxx]

Check to make sure the wastegate actuator arm hasn't fallen off the wastegate flapper arm post. Usually if this happens, you'll get a max boost of 0 psi, but no higher.

Do a boost leak test. Inspect all the intercooler pipes to see if any of them have popped off.

Check the turbo for shaft play. Take off the intake pipe and try to wiggle the compressor wheel up and down, in and out, side to side. Noticeable play in any direction may indicate that the turbo is shot. Try to spin the compressor wheel to make sure it spins freely and isn't jammed. A couple days ago, someone found a washer or nut or something jammed in the turbine wheel.

 

[bartels903]

Check to make sure the wastegate actuator arm hasn't fallen off the wastegate flapper arm post. Usually if this happens, you'll get a max boost of 0 psi, but no higher.

Do a boost leak test. Inspect all the intercooler pipes to see if any of them have popped off.

Check the turbo for shaft play. Take off the intake pipe and try to wiggle the compressor wheel up and down, in and out, side to side. Noticeable play in any direction may indicate that the turbo is shot. Try to spin the compressor wheel to make sure it spins freely and isn't jammed. A couple days ago, someone found a washer or nut or something jammed in the turbine wheel.

Could you explain further on how to check for the WG actuator arm, I have yet to learn my way around a turbocharged engine.

Boost leak test will be tommorow.
I will check for shaft play tommorow.

 

[MrBoxx]

Could you explain further on how to check for the WG actuator arm,

No problem. On the bottom of the 14b is a brass-colored (well, mine's rust colored) can bolted to the compressor housing. That's the wastegate actuator. From this little can there should be a long rod coming out of it. The end of the rod has a hole in it. This hole is supposed to over a post on a little flat arm that's attached to the turbine housing. That's called the wastegate flapper arm. So the rod goes over the post, and there should be a little cotter pin to lock it on. Sometimes that cotter pin deteriorates and falls off or it breaks and fall out. If that happens, the arm falls off the post, and the wastegate flapper arm is free to move. The wastegate flapper arm is connected to the actual wastegate flapper, which is what lets excess exhaust out before the turbine wheel, which limits the amount of boost you can make. If the wastegate flapper arm is free to flap around, then the turbine wheel won't receive enough exaust to make boost. In most cases, people say the turbo will make 0 psi, but no higher. That was the case when my cotter pin fell out. I replaced it with a paper clip.

Here's a pic I found to help explain what the flapper arm and wastegate actuator arm look like.

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[bartels903]

Thanks man, I bet I knocked it out today, I was messing with my MBC to get it to 13 psi instead of 16 psi. I will check tommorow. Thanks again for the help.

 

[oldman]

Check to make sure the wastegate actuator arm hasn't fallen off the wastegate flapper arm post. Usually if this happens, you'll get a max boost of 0 psi, but no higher.

Depending on which turbo and the wastegate flow capacity, some boost should still be reached at higher RPM's. My old 16g was able to build 7-8psi by 5-6k prior to porting and 2psi after.

 

[scottsee]

I replaced it with a paper clip.

haha, yeah, me too

 

[MrBoxx]

Right. I forgot to mention that was on my T25, so low boost is a given.