Fluctuating vacuum - is this bad?

bumping into this section. i'd appreciate any help i can get!

My question: Is this normal for the 2.7? I have the idle shake. This vacuum test seems abnormal, but I don't really know. The actual flicker of the needle is a little faster than it shows in the video. See the video:

https://youtu.be/751gE6O2KTY

my full post:
https://www.tacomaworld.com/threads/help-me-understand-vacuum-test.792882/

Thank you!

 

What year is the truck, and how many miles is on it? Where are you measuring the vacuum? Is this being measured with the engine warmed up or cold? ...

 

Thanks for the reply! 2016 tacoma access cab 2.7L 4wd
73,000 miles
Measuring when cold or warm (not much change) with a mighty-vac hooked into the line that connects the intake manifold to the brake booster (I unplugged the booster side and plugged the hose into the vacuum gauge).

Vibrates at idle, worse in gear. Better after driving on the highway for 10 min, worse in stop and go driving. I feel it in the back and head of the seats. No codes, zero misfires in OBD2, but it feels like it’s imbalanced or missing slightly even in park. I have replaced spark plugs, cleaned throttle body and MAF and idle long term fuel trim is -3.

just wondering if I need to pursue this fluctuating needle more or if it’s not related to my vibration problem. Thank you!!

 

Any valve tick? A sticky lifter can cause this.

 

Yes, a little bit especially when cold. I put marvel mystery oil in the fuel yesterday. The oil was supposedly changed by the Subaru dealer I bought it from last month and it looks fresh on the dipstick.
If it’s a sticky valve, what else can I do to diagnose it or fix it? Thank you again !!

 

There aren't too many options (for the shade tree mechanic) besides tearing into the engine, or trying to clean the possible varnish causing the sticking. You could try using some Toyota brand "Engine Oil System Cleaner". Or you could try something like MMO or another aftermarket oil additive specifically for quieting sticking valves. If that doesn't work an engine flush may help. Now, this may help your fluctuating vacuum issue "if" the problem is a sticking valve.

 

Thank you very much! I will try that engine cleaner from Toyota.

 

I hope this solves your issue. Let us know either way.