I mean that the water temp gauge needle goes way past the point to where it bottoms out and so does the battery volt gauge needle and the oil pressure gauge needle and the tach needle works when it wants to.
A tool that measures air pressure in a tire or going through a pipe is called an air pressure gauge.
The oil pressure gauge is going to fluctuate on a Toyota Tacoma or any automobile. The oil pressure is less when the auto is idling and more when the auto is going down the road.
Check your oil pressure gauge, if your just going by what it says the gauge might be wrong Iv had this happen bout 4ish times and its always the tube running to the oil pressure gauge is pinched so its not getting a good reading.
It might be the alarm system; or your car is going haywire.
No, There would not be a 4500 version of Silverado.
sounds like the cam bearings may be going bad
Take the wire loose from the oil sending unit and then turn the key on and ground the wire to the engine somewhere and the gauge in the truck should go all the way past the highest point. If it don't then the gauge in the dash is bad are the wire going to it ( The 1 you grounded ) is broken. If the gauge is reading low oil pressure, Then unscreew the oil sending unit on the engine just behind the distributor, were you took the wire loose from. Then install a OIL PRESSURE GAUGE into it's place. Then start the engine and read the pressure, Now compare the reading on the dash gauge to what you are reading on the oil gauge.
You may need a new pressure gauge. They are inexpensive and can be found at any place that sells pool products. OR That may be all that you are going to get out of the system you have.
That, or the gauge is going. Or a loose wiring connection. I'd bet on the last.
Your gauge could very well be bad, many pools that we took care of the gauge on the filter was bad, after backwashing the filter just check any of you lines going back to the pool and your should notice the pressure is a lot higher. A lot of people just check the flow by placing there hand at an outlet to check pressure than by walking over too the filter and reading the pressure, instead of buying a new pressure gauge.
This depends how you are perceiving this "pressure going up and down" . I've repaired and replaced toilets for years and couldn't imagine how I'd gauge pressure doing this. Maybe you are mistaking pressure for flow rate and something is plugged up somewhere in your toilet.
I'm going to add an oil pressure gauge to my 05 GTO. Where's the sending unit located on the 6.0 L engine