[header] How to do a compression test [title] Bring the engine to its normal running temperature. [step] This can be done in the following ways. [substeps] If you haven't driven your car recently then the engine is most likely cold. 
Start your vehicle as usual and keep the engine running for a few minutes. This should warm up the engine to its normal operating temperature; however you should be careful not to overheat the engine by keeping it started for too long.