Intermittent loss of power

HEAVYD223

MEMBER
2005 CHEVROLET TRAILBLAZER
4.2L
6 CYL
2WD
AUTOMATIC
60,000 MILES

My vehicle has a slight loss of power at times and if I turn the A/C off you can feel it gain power instantly, but when im stopped in gear it will idle erratically then even out. But soon as I attempt to accelerate it will almost stall, some days I get in tho and it's ready to go like it's running perfect. I have pulled the plugs they look great, I tested the coils with multimeter and all 6 are almost exact same readings. The truck was owned by a elderly couple who took care of it and all the service has been on schedule. Now the stepper motor for the oil "pressure" gauge went bad so I removed the pressure sensor and bought a mechanical gauge, but when I was changing it I figured I'd pull the VT solenoid and clean it and test it. So I immediately noticed the plastic and all that is encased in the metal housing will spin freely inside the metal which I've never seen any do that the 2 on my beamer don't, so i'm suspect that its bad or going bad. However I have used a foxwell nt 510 Elite obd2 scanner and there is no pending or stored codes and no check engine light. I did plug it in last night and collected some live data I can provide you with.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Couple of things to clarify first as that can help figure this out. If you have the A/C off, does this happen at all?

You said that the power will pick up when the A/C is off but if you leave it off, does the vehicle drive normally?

Also, has this done this the entire time you have owned it?

Next when this VVT solenoid spins, can you get a video of this so that I am sure I understand what you are seeing?

I am including a bunch of info that you may not need by the sound of what you have done so far. However, it is all great info and it may trigger something with you that will fix it.

https://youtu.be/U1RoG3I-Oww

https://www.2carpros.com/articles/how-camshaft-variable-valve-timing-works

As for what I understand you are removing the solenoid but I just want to understand the plastic part you are seeing spin.

Take a look below and let me know if this is what you are seeing. This is the replacement process for this just to be sure we are seeing the same thing.

Let us know this info and we can go from there. Thanks

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