Whats the ideal or stock compression on the 240s?

GT500916 · #1 05-17-2005, 03:28 PM

Im going to do a compression test on my 240 tomorrow and what is the stock compression? and what is a good compression on a 129k car?

thanks

monooxide · #2 05-17-2005, 04:00 PM

179 PSI is the norm... and 151 is the minimum. And no more then a 14 PSI diff between cyl.

GT500916 · #3 05-17-2005, 06:13 PM

alright tomorrow we will find out... ill change spark plugs and do the compression and we will see where i stand..

GSR2NR94 · #4 05-17-2005, 10:06 PM

My compression wasn't that bad then because it was
1: 170
2:165
3160
4:165
I guess thats not too bad.

nissanfanatic · #5 05-17-2005, 10:42 PM

FActory spec is 179psi
Minimum spec is 151psi
max difference between cylinders should be no more than 14psi.

Since gauge difference is possible, look for difference in the cylinder readings. IF they are teh same or close to, then you're golden. Low cylinders, try adding a tablespoon of oil to. If readings come up, then you have bad rings.

Remember to press the throttle to the floor when cranking. Remember to run the car out of fuel. I like to pull the injector clips and coil wire too.

GSR2NR94 · #6 05-18-2005, 03:02 AM

Why do you put it to the floor? Is it just to initiate clear flood mode so that you can crank it and it will not start? Thats what I figured, but I just pulled all of my wires.

nissanfanatic · #7 05-18-2005, 11:07 AM

To allow the cylinders to completely fill with air.

GT500916 · #8 05-18-2005, 03:41 PM

cant do compression today as planned, my dad took my car to work cuz the blazer he driver got a little leak going in the tranny ... so tomorrow!!

GSR2NR94 · #9 05-18-2005, 05:16 PM

which is called clear flood mode.

nissanfanatic · #10 05-18-2005, 08:52 PM

Okay. Far more advanced than my talk.

GT500916 · #11 05-19-2005, 06:03 PM

ok just did compression as promised , results are

1- 197psi
2- 189psi
3- 189psi
4- 190psi

the engine was really hot because i just came home from a little drive. Also the oil has been changed on it every 3-5k miles by the first owner and by me, passes smog great, has lots of torque and power... so id say its a brand spanking new car and im happy

i dont even know the stock compression.

monooxide · #12 05-20-2005, 12:53 AM

The stock numbers are 179 norm and 151 Minimum? What...? 197?

GT500916 · #13 05-20-2005, 02:26 AM

Quote:

Originally Posted by monooxide

The stock numbers are 179 norm and 151 Minimum? What...? 197?

dude im freaken serious!! i did the compression a few times just to make sure, kept getting the same results... like i said i drove the car for like half and hour before the compression... but still...

and i did the soupra compression test just the other day so i know what im doing... for a 130k miles on the 240 hecka good results... unless i have a new engine and the owner didnt say nothing about that?!!

orestes · #14 05-20-2005, 02:44 AM

wtf? did you get a lower profile head gasket maybe?

GT500916 · #15 05-20-2005, 05:06 AM

Quote:

Originally Posted by orestes

wtf? did you get a lower profile head gasket maybe?

nope! thats why i dont know whats going on. maybe i got some dome pistons in there hahah

my best guess is the engine is new or has been rebuild by the first owner, because he did take care of the car and kept it all stock and changed oils and this and that...

maybe my block shrunk sleaing the rings better after 130k wear...

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