What should I do when my '98 VW jetta's RPM spikes to 40,000 while in park?
You should have the throttle position sensor checked and tested in addition to the throttle body. Take the car to a VW dealer or service center and have it checked out for professional advice.
Get it checked out....
It doing that many RPM's in park then
40 grand, you just can't fault German engineering. lmfao. But really, it could be just a loose connection for the tachometer.
Take cover, pistons, push-rods, rocker arms, and valves are about to be propelled towards the stratosphere. BTW, how come your tachometer goes that high?