Uneven compression

[goodcar]

1 and 2 are 90 psi. 3 and 4 are 80. 5.5 head, counterweighted crank and lightened flywheel. Should I be concerned??

 

[Gary WA]

No!

 

[Mulletwagon]

Enjoy your ride !!

 

[CWPASADENA]

I agree,

I would not get more involved at this time, drive it!

Chris W.

 

[Big hammer]

4oz MMO in the gas tank, go for a drive, Enjoy!

 

[nkaminar]

It could be something as simple as variation in valve lash or variation in the camshaft lobes. Or a small leak in one of the valves. I would not worry about it until it gets down to about 60 psi in the lower cylinders. If you want you could check the valve lash as that is a regular maintenance procedure. Also, re-torque the head nuts to 55 foot-pounds, another regular maintenance procedure.

 

[Merc Cruzer]

1 and 2 are 90 psi. 3 and 4 are 80. 5.5 head, counterweighted crank and lightened flywheel. Should I be concerned??

Did you check them when the engine was cold or hot?

 

[goodcar]

Did you check them when the engine was cold or hot?

Hot, throttle wide open.

 

[Werner]

4oz MMO in the gas tank, go for a drive, Enjoy!

That's also my opinion. Do you drive short distances? Drive a long distance (>40 mls) with alternating power in the upper range.