RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   Poor man's compression test question (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/poor-mans-compression-test-question-1006728/)

PistonSmash 07-30-12 07:21 PM

Poor man's compression test question
 
I'm having issues with my car that led me to do a compression test on my car. I bought a regular tester which does not fit in my engine, so I decided to do the poor man's compression test detailed by aaroncake. I have the lower spark plug removed from the rotor chamber closest to the fire wall. I turn the engine and I don't hear ANY "psst" sounds at ALL. I'm not sure if it's because my battery is slightly low (although I plugged in an electric battery jumper pack) or because ALL my rear rotor seals are blown.

We first tested the rotor closest to the front of the car, although we stupidly removed the top spark plug instead of the first, we did the test and we had steady "psst..psst..psst" sounds of good compression.

I need help, fast!

AGreen 07-30-12 07:50 PM

I doubt ALL apex seals are blown.

Why won't the compression tester work?

AGreen 07-30-12 07:51 PM

Usually you get better whistling if you pull the top plugs, since they're smaller holes for the compression to escape out of.

Have you tried holding your finger over the spark plug hole while a friend cranks it?

PistonSmash 07-30-12 08:22 PM


Originally Posted by AGreen (Post 11174333)
Usually you get better whistling if you pull the top plugs, since they're smaller holes for the compression to escape out of.

Have you tried holding your finger over the spark plug hole while a friend cranks it?

It's blown. Sounds like a lawn mower and won't stay on. The rear rotor is gone. I don't know why or how...but.

Compression tester for some reason wouldn't fit in the hole. I don't really know lol. Thanks for responding though. I know you're super knowledgeable. Thanks for trying to help :/ I appreciate it a lot.

RotaryEvolution 07-31-12 11:07 AM

no sound is a pretty definite conclusion of no compression. no compression is due to carbon stuck seals or broken seals ejected from the engine.

you can try some lubricant in there to unstick the seals or use a mirror and look through the lower plug hole and see if the apex seals look chunked.

rxat2012 07-31-12 03:36 PM

If its a turbo check your hotside wheel..... Good luck bro

devilxavierz 08-01-12 07:31 PM

Do you have trouble starting it?


All times are GMT -5. The time now is 09:51 PM.


© 2024 MH Sub I, LLC dba Internet Brands