Waste gate removel

[Scout54]

Hope I don't embarrass myself cause I'm new to all this diesel stuff but I'm sure someone has been here too. So here goes 2003 dura max LB7 was not building pressure or boost it was like the governer was kickin in at 40mph. Neighbor looked at the waste gate and we could not make it budge, so I popped the clip off the arm and the plate would swing freely so is the WG the upper piece with the hose at the top gone bad on me. Oh I did drive it after I unhooked it and there was a difference. Is that a part you can just replace? Thanks for the help.

[DmaxMaverick]

Welcome aboard! The wastegate actuator/pod is spring-loaded closed, and is forced open with intake charge air pressure. It should be firm closed at zero to before max boost, then forced open when max boost is neared. You can test it with shop air. Gradually apply up to 30 PSI to the air inlet. It should begin to "soften" around 19 PSI, and be fully engaged around 27 PSI. If the wastegate (disconnected from pod) moves freely, and the pod works, that's not your problem (almost never is). Your lack of boost is probably fuel supply related, or you have DTC's (trouble codes) limiting power (Limp Mode). If the SES lamp is on, that's a likely case. If no SES, then you may have a fuel restriction (filter, most likely), or a significant air leak. Change the fuel and air filters, make sure you have fuel in the tank (don't laugh, stranger things have happened), no leaks, and check for any DTC's.

[Scout54]

I clamped some vise grips to the rod and was able to get the rod to move (toward the firewall) but it was very stiff and took alot of force. I have had no lights come on, havenot went to a shop to have codes read yet, is black smoke telling me I am burning enough fuel or is that not a measure to go by, cause it does blow some when I get on it. Forgot to include the edge juice built in 2003 is also installed and has been since 2003. We did take it out to see if the same thing is happening without it and it was so I figure that rules that out.

[DmaxMaverick]

Black smoke only means more fuel than air to burn all of it. Check your air cleaner element and the entire intake plumbing. A blockage, somewhere before the boost sensor, or a leak after the compressor. If the SES lamp isn't on, you don't have a current DTC to worry about. Any sensor condition significant enough to cause black smoke will certainly trip a DTC or two.

[Scout54]

The compresser is down side of turbo? Is there specific hoses to look at for leaks and a way for me to check for them if they are not visibly bad. Boost sensor is I would assume before the turbo.

[DmaxMaverick]

The compressor is the aluminum half (intake), and the turbine is the iron half (exhaust) of the turbo. The WG is located after the turbine wheel, on the exhaust side. The boost sensor (or just a fitting connected to tubing) will be located after the compressor (the air cleaner is located before), at or before the intake plenum (last stop before entering head). The hose that is attached to the compressor outlet goes to the WG actuator pod (the pressure source that opens the WG).

A most common "leak" in the CAC/intake plumbing would be one of the silicone rubber hose connections (loose clamp, or just slipped off), damaged hose (cut/abraded/burned/ruptured/punctured/chemical), or any chafe point on the aluminum pipes. Most often, if you have a CAC leak, it will be noisy (loud hiss/buzz/whistle).

Could also be a failed turbo. (Engine OFF) Remove the pipe fitting immediately before the compressor inlet (center of the housing, not the extended end of the "snail"). Check the compressor wheel for free movement by hand (NO tools). It should spin freely and not wobble more than just the tiniest bit, and in no case, should it contact the housing. If it doesn't spin, drags, grinds or contacts the housing, it's bad. If everything checks out, you'll have to get a look at the other side. The WG may be damaged or blocked from full travel to closed, although this is a much less common issue.

[Kennedy]

I think you are misunderstanding how the wastegate works. It is essentially closed all of the time. If boost and drive psi get high enough it starts to bleed off. In other words it SHOULD act like you describe.

If the wastegate flapper seats (rotate counter clockwise as you face it) and clunks shut then the plate is still on it. From there your pressure can is NOT the problem.

Put the linkage back on and look elsewhere. Plugged fuel filter etc. Yes it could be a plugged filter like Mav said.

A boost gauge would be quite handy in diagnosing as would a filter restriction gauge.

Also, any other odd operating characteristics that you haven't mentioned like hard starts, long cranking time etc? There's often information withheld that comes out in the end and would have beenn a smoking gun had it been mentioned.

[Scout54]

With yalls info I have been able to rule out the waste gate thing I do (now) understand how it works, haven't had time to visually check the turbo but am now finding it to be more intermittent driving it to Idaho this weekend it was not feeling the restriction around 40 like it was. I have plans to trade in my juice for the new one with the CTS so I hope that might help on the diagnosis. Before then I plan on doing a good visual like on hoses, clamps, etc that was suggested earlier so I will do that. I will also change fuel filter while doing my next oil change. Thanks for all the help, I will keep in touch.