Want to do a compression & leakdown test on MCS. I know how to perform the comp. test and have a leakdown tester. Do I have to remove the valve cover to determine TDC on comp. stroke or is there an easier way like dowel rod down the plug hole? BTW, will running the comp. test throw a code? If so, will I be able to clear it with my Peake tool after re-installing all the plugs? (If this were a 289 HiPo, I wouldn't need any help!)
TIA!

 

Remove all the plugs to lessen the pressure when you crank the motor (8-10 rounds). Start plug 1 to 4. To the lowest reading, I squirted a light motor oil, crank 4 rounds to distribute oil, then put in the compression gauge to get another reading. I'd just hold the pressure and see how fast and how much it drops or holds. It did not throw codes.

 

Thanks! Good to know about the codes. Bentley manual warned that it might throw one. Now, need to find EZ way to get TDC for leakdown test.