OTC Tools 5610 Transmission Engine Oil Pressure Tester Kit - Professional Diagnostic Tool for Automotive Repair Shops & DIY Mechanics (Check Oil Pump, Gauge Pressure)

This worked great for testing oil pressure. The manual is a bit ... well, there isn't really a manual per se. You have to infer everything, watch YouTube videos, maybe even read some forums. Here's a couple of things I learned:1) This kit has brass fitting. These are used for 90 degree elbows, extensions, size changes. All of these are NPT threads.2) This kit also has aluminum fittings. These are used to connect between a brass fitting and the car's oil pressure sensor port. Aluminum is softer so I have to assume this will help prevent warping the car's port.3) You can use teflon tape around the NPT brass fittings, but do NOT use teflon tape around the aluminum fitting that you screw into your car. You absolutely do not want to get a piece of teflon into your oil system as it can cause problems.4) Make sure to hold the oil sensor screw threads against the aluminum fitting and make sure the threads match EXACTLY. For example, the Kia Rio I was testing had 1/8-28 BSP threads. You also get a few other common aluminum adapters for various auto manufacturers. Call the dealer service department if one doesn't match and find out what it is. Someone somewhere surely sells an aluminum adapter to match.5) Start screwing the aluminum fitting into your car by HAND. After a few rotations it starts to get too tight to hand turn, so use a wrench to continue until it just starts to get tight. Do not overtighten.6) Start the car and watch the oil pressure for at least 5-10 minutes. Oil pressure psi will be higher when the car first starts and will gradually decrease as the oil warms up. The car I tested started around 60psi and gradually decreased to 26psi. The main thing is you don't want it below 10psi at idle. If it goes below 10psi, you will probably want to turn the car off or else risk ruining the engine. Check the service manual to know your car's exact range.7) When you accelerate the car, the pressure should jump up. For example, the car I tested jumped from 26psi to 60psi.8) You don't want to see needle bouncing all around. That can be a sign of low oil or a pump going bad. It will slightly move with the RPM of the car, but it shouldn't be bouncing everywhere.9) Depending how high up the oil pressure sensor port is located, you may have to drain some oil out of the system before you can unscrew the oil sensor without oil running everywhere. Don't forget to top it back off before testing. After testing, you may then have to drain some oil again before unscrewing the test adapter and putting the oil sensor back in.This tester gave me the peace of mind that the oil pressure in the car I tested is fine, and the oil pressure dashboard light illuminating is most likely due to the wiring harness. It can be safely driven to a mechanic to have the wiring repaired.