Clicked over 130K today and I did a compression check cause I will be adding a s/c soon so i wanna be safe...

It depends on how I did the test.

#1-- I took everything out, including all 6 plugs and all 6 packs and the fuel pump fuse and each cylinder was exposed and did it that way and got about 175 accross each cylinder...

Well later I wondered and went and did it again...

#2--- I did it cylinder by cylinder, I unplugged all of the coil packs so that engine wouldnt start and took out every plug one at a time (plug out, test it...plug back in, next one) and came up with 190 consistantly accross each and every cylinder...

My question is what is the right way to do this ?? I got good readings first and the second time I got even better readings

I wasnt getting good readings after the first crank of a few seconds..I had to do it a few times to get good readings..maybe 5 times

I am Super Charging in a few weeks, and I want to be %100 sure my engine it in perfect shape..it doesnt burn a drop of oil between changes and the engine has 130K...you think im safe ??

-matt

 

Did you have the fuel pump disconnected the second time? If the pump was injecting fuel during cranking, maybe the presence of the fuel will raise the compression since it is incompressible and takes up a little space that would normally be occupied by air. Just a thought.

Either way, the important thing is that both times you got compression readings that were within the normal range, and more importantly, there was not a large variation between highest and lowest numbers. For boosted operation, 175 is better than 190, though.

But, regardless, I'd say you're good to go with the SC.

 

you shouldnt be going on how long the engine cranks! You should be watching the needle to twitch three times, after that STOP cranking and thats you reading. You can sit there and crank all day, till you get a reading you like, but it wont be right.

 

yea well the normal reason I went 5 times was to squeeze that extra few PSI out and thats what people told me to do...Normally the first crank it went up alot, then the second went up a tiny bit and the third a little bit more...the 4th and 5th pretty much moved nill to none

The fuel pump was only disconnected when I took off all the coils and all the plugs at once...when I went plug to plug with the coils off I DIDNT unplug the Fuel Pump Fuse

I wanna know if im pretty safe to boost

-matt

 

Your engine is in good shape. The first method is what I use.

 

dont see why not, as long as you dont do to much.

 

When I cranked with the first method it sounded Weird..NOt like a normal crank I would hear with everythign hooked up ?? Probably normal ??

-matt

 

It's bound to sound different with all the plugs removed, don't you think? You worry too much, matty.

 

That's normal. It sounds like puff, puff, puff..