Glossary / General

compression test

13 Episode Mentions

Too Afraid to Ask

It checks how well the engine’s cylinders are sealing. A low reading can mean worn rings or valves, while a high reading shows good engine condition.

Technical Definition

A compression test measures the pressure each cylinder can generate when a spark plug fires, indicating engine health and potential wear.

Hear It Discussed

"They have to do a compression test because that's going to tell you all. And if, in fact, the compression is low... you will need to have the engine rebuilt."
#2633: Hacker Heaven The Best of Car Talk 31:22

"have you done a leak down test? Not a compression test, but a leak down test to see if all the cylinders are sealing?"
Guys Giving Free Car Advice Over The Air You Can Call Too Under The Hood show 07:01

"You could do a compression test. But if the rings are faulty, you know, or could you know, are they just going to they could let go? Who knows? Right?"
Ron Ananian, The Car Doctor - April 4, 2026 - Hour 2 - The Right To Repair Ron Ananian The Car Doctor 03:10