Compression test help.
#1
Ok so my 98 Max has 18k on it now, and I use the juice and I'm on vacation!! Sooo lets do a compression test to check that motor out.
Since I'm cheep and havent bought a shop manual yet, I need some one to please tell me what the procedure is to do this correctly, disconnect the fuel system (how?), etc etc etc? and what the factory tolerances are.
THANKS!!
Since I'm cheep and havent bought a shop manual yet, I need some one to please tell me what the procedure is to do this correctly, disconnect the fuel system (how?), etc etc etc? and what the factory tolerances are.
THANKS!!
#2
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I've transcripted the Service Manual page regarding this ->
Straight from Page EM-10 of the Factory Service Manual (for 1996 Maxima):
"
Measurement of Compression Pressure
1 Warm up engine
2 Turn ignition switch off
3 Release fuel pressure (remove fuel pump fuse and crank engine a few times)
4 Disconnect ignition coils
5 Remove all spark plugs
6 Disconnect all injector harness connectors
7 Attach a compression tester to Cyl 1
8 Depress accelerator pedal fully to keep throttle wide open (or rig at throttle body)
9 Crank engine and record highest gauge indication
10 Repeat for every other cylinder
11 If compression in one or more cylinders is low, pour a small amount of engine oil into the cylinders through the spark plug holes and re-test.
Notes:
- If adding oil increases compression, piston rings may be worn or damaged. If so, replace piston rings after checking piston.
- If pressure stays low, a valve may be sticking or seating improperly. Inspect and repair valve and valve seat. If valve or valve seat is damaged excessively, replace them.
- If compression stays low in two cylinders that are next to each other:
a) The cylinder head gasket may be leaking, or
b) Both cylinders may have valve component damage. Inspect and repair as necessary.
Standard 185 psi @ 300 rpm
Minimum 142 psi @ 300 rpm
Difference between cylinders 14 psi @ 300 rpm
Use a compression tester whose rubber end is less than 20mm in diameter. Otherwise, it may be caught by the cylinder head during removal.
"
"
Measurement of Compression Pressure
1 Warm up engine
2 Turn ignition switch off
3 Release fuel pressure (remove fuel pump fuse and crank engine a few times)
4 Disconnect ignition coils
5 Remove all spark plugs
6 Disconnect all injector harness connectors
7 Attach a compression tester to Cyl 1
8 Depress accelerator pedal fully to keep throttle wide open (or rig at throttle body)
9 Crank engine and record highest gauge indication
10 Repeat for every other cylinder
11 If compression in one or more cylinders is low, pour a small amount of engine oil into the cylinders through the spark plug holes and re-test.
Notes:
- If adding oil increases compression, piston rings may be worn or damaged. If so, replace piston rings after checking piston.
- If pressure stays low, a valve may be sticking or seating improperly. Inspect and repair valve and valve seat. If valve or valve seat is damaged excessively, replace them.
- If compression stays low in two cylinders that are next to each other:
a) The cylinder head gasket may be leaking, or
b) Both cylinders may have valve component damage. Inspect and repair as necessary.
Standard 185 psi @ 300 rpm
Minimum 142 psi @ 300 rpm
Difference between cylinders 14 psi @ 300 rpm
Use a compression tester whose rubber end is less than 20mm in diameter. Otherwise, it may be caught by the cylinder head during removal.
"
#5
Have you ran a compression test since going with boost?
Originally Posted by MardiGrasMax
5 cylinders at 210psi one at 207.
If 185 is standard the 210 is like new?
Wow, Mobile 1 really works! Even on the juice!!!
If 185 is standard the 210 is like new?
Wow, Mobile 1 really works! Even on the juice!!!
#8
Originally Posted by MardiGrasMax
5 cylinders at 210psi one at 207.
If 185 is standard the 210 is like new?
Wow, Mobile 1 really works! Even on the juice!!!
If 185 is standard the 210 is like new?
Wow, Mobile 1 really works! Even on the juice!!!
could your compression ratio be higher because of the setup??? thats what it looks like
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