Loose belst
Opp's that's belts
Many things can cause lag while driving at a low RPM but not at a high RPM even if it is not the vacuum hose disconnected from the EGR valve as it could be the fuel filter. It can also be the park plugs.
Gears slipping, such as sudden high RPM's and loss of power while driving. Failing to change gears at a certain RPM in an automatic.
If the Yukon engine has high rpm while driving, check the transmission for slippage, that will cause the engine to over rev. The overheating could be caused by the high rpms.
What can cause the RPM on a car to jump while driving is a problem with the transmission. It could be a problem with the gears in the transmission itself.
does it do only when driving? if so, could be many many things.if it does it while you are at a stop and at a high rpm, its probably a bad bearing in one of your pulleys.
while driving the rpm gauge work perfect, when start accelerating the rpm can not exceed 3 with interruption in the engine
Just fixed this, was a loose vacuum line next to intake
NO
Not at all. Overdrive is for high rpm acceleration like quick on ramps and passing, or even going up a hill. In snow u want a lower rpm so u don't lose traction.
depends on what car and what engine, typically if your cruising on a freeway, you will be running at half RPM or at the most 3/4, but the lower RPM the better with that you get better gas mileage.
while you are in park? That should be normal. While in gear or driving, no that isn't.
transmission is slipping