TRD Supercharger related question, boost leak?

If the bypass valve is stuck open as you get into boost, will the gauge still read boost?

My boost gauge is reading close to 9-10lbs when it should only show 7lbs max, but there is no power. The truck feels like it's running only on motor. I can also hear a big air leak as I get into the throttle that was never there before. I can blip the throttle and my guage will read 5-6lbs right away, but there's no power behind it. All hose connections seems to be good.

Anyone have any idea where I should start looking?

 

What kind of gauge is it? Old school vacuum or electronic? secondly, where is the probe placed to see its reading? W/the valve open you shouldn't build boost. Can you manually by hand move the valve? If its driveable that's good. Have you checked the belt?

 

Another thing besides the bypass valve is get some brake cleaner and spray around and see if the motor races to check for a leak.

 

The gauge will not read boost as you are supposed to get into it as the system is not sealing up in order to pressurize the manifold. However, since the valve is erratic, it is possible it is sealing up temporarily which is causing the sudden boost reading you see, before fully letting go and allowing all vacuum to exist all the time. This is actually a pretty common way that BBV's fail.

Your boost bypass valve is probably stuck open and is allowing the vacuum to escape past it, creating an "internal" air leak hence the sound you can hear.

We have a thread specifically for anything blower related these days. There is a ridiculous amount of info on there.

Replace it and move on with your life Vince.

 

Thank you for the assistance.

It's an autometer mechanical gauge. It's a TRD SC so there's a boost port at the top back of the SC. Yes, I can manually move the valve back and forth. Belt looks good. I replaced it about 3k miles ago. There doesn't seems to be signs of it slipping. I've been running the SC for about 45-50k miles total now.

I will need to do this.

It's exactly what I'm thinking as well.

 

Quick test. Remove the vacuum source from the valve, and plug the hose. Valve should be fully closed at this point . Test drive and see if boosted power returns.

 

Great idea! I will try to do this today.

 

I found the issue. After I did the bypass test, some of the power came back, but I knew it wasn't 100%. During the test drive, I went about 1/4 throttle and heard a loud POP and saw a puff of black smoke in the rearview lol. I eased off and went back to the warehouse and plugged everything back on. The next morning on cold startup, I can hear a noticeable rattle coming from the exhaust. I drove it like this for a few days until I had time today to crawl under there again. I knocked it around with a rubber mallet and sure enough the Magnaflow hiflow cat made a clank clank sound. I took the catback off and saw this,



I added this to lessen the exhaust fumes, but after 2yrs, it wasn't having it anymore. I decided to just gutted it out for the time being.



I put the catback back on and took it for a spin and life is all good again.

 

Part bypass and majority catalytic converter. Glad you were able to get it sorted.

Was any of that converter material balled up and deformed?

 

I have a dent on the outside housing of the cat from an offroading trip last year. Whatever Magnaflow uses to hold the "honeycone" part of the cat must have been compromised by this dent. I think it eventually broke causing the honeycone to shift and move freely. It must have rotated somehow and ended up plugging and restricting the exhaust flow. It was still one chunk. I either had gut out the cat by breaking up the material or weld in a new cat. For the time being, I decided to just gutted it out.

 

Had a similar issue on my '01 Subi. Cat has broken, then bounced around and melted into a strange deformed ball.

 

Was it an OEM or aftermarket cat? These hi-flow Magnaflow cats never seem to last more than 2-3yrs from my experience. I guess that's why they're $100 .

 

True. Kind of like the packing in their mufflers. Lol.

It was an OEM cat.

 

With 300,xxx miles.

 

Exaggerator. It was barely over 200,xxx.

 

time to get over to the 4.0 tips and tricks and bring that SC to the next stage of its life... =)

 

This is my daily so I need it to be as reliable as possible when it comes to the motor. My hands are already tied with my other projects that needs to get finish.