I can confirm that there are no signs of external oil leakage. The skid plate came off a long time ago and I don’t recall ever seeing an oil slick.
I haven’t checked any vacuum tubes, but I can do this. Is there an easy way to check for leaks if there are no visible cracks?
How do I identify all the hoses in the vacuum system? Where is the PCV valve located so I can check it? Is it white or black?
How should I check if it is blocked? Blow on the side of the cylinder head with different pressures in the mouth and gently blow on the other side to make sure it is closed without pressure?
I will admit that although I am quite handy, almost all previous attempts to fix my vehicle’s problems have resulted in a worse situation.
I can easily install a wired backup cam, but ask me to change a spark plug and I’ll manage to pass it no matter how careful I am.
Granted, the example I drew from was a small light socket and the block was aluminum so mistakes were easier to make.
deviate.
A compression test seems like a good idea. Is this something most mechanics can perform?
Will this just give general compression ratings, or does it give a separate reading for each cylinder?
The idle is very quiet and stable, and only drops when there is a load change on the alternator.
It’s useful to know that the engine revs at 4k RPM. I live in the mountains, but quite small ones (mostly 1k-3k ft high).
I’m always trying to run it somewhat hard at higher RPM ranges in hopes of “burning out” the source of the problem (doesn’t work).
However, this is my wife’s daily driver and she always tries to maximize fuel economy, keeping RPMs and load as low as possible.
Being able to maintain 75km/h on gently sloping mountain highways without downshifting in 5th, however, hampers its fuel economy goals.
I want to be clear about this issue, in the hope that it will help with the diagnosis.
It’s remarkably consistent regardless of load, pedal pressure, speed, gear, etc, and doesn’t feel like it’s going into a powerband.
It’s a very defined line, and feels bright above the line and wet below it.
Reminds me of my 99 VW turbo diesel. I had a bunch of cheap injectors installed and they didn’t all open at the same pressure.
The result is a very clear difference between “firing on all cylinders” and “not”.
Only the problem was much less stable and predictable.
Thanks again for your willingness to help!