This DIY steps are based on thread that no longer exists on TN forums (was started by pgmomni who is no longer a member of TN). Thanks to TrailDust who restored it from archives I compiled this information on compression testing the 5s-fe engine.
Original posters who contributed (chronological order of original thread) were: pgmomni, Nervous, Chris Crash, 93celicaconv, fenixus, hill8570, 73sport, JohnGD, Stillrunning.
For now there is no pictures in it, but instructions are pretty straight forward including all the member comments on crucial issues.
1. Tools required:
tools for removing the spark plugs which may include 3/8'' ratchet, a spark plug socket and extension.
Torque spec for spark plugs re-installation is 13ft-lbs
Compression tester/gauge with M14 fitting
Get a quality compression tester. Autozone loaner gauge i tried (Actron or OEM p/n 27138) may give you a false reading, because of the loose rubber hose at spark plug fitting, so you won't be able to secure it in a plug hole (learned that the hard way).
Good idea is to get a nice compression test set (not the cheapest one) from Harbor Freight Tools, like this:
2. Warm up the car to normal operating temperature
You should test compression on WARM engine, cold reading may be misleading. You are supposed to test all cylinders as quickly as you can (without destroying things LOL
), so you get a comparable results.
NOTE: if you have a front strut bar, unbolt it now for quick & easy access to spark plugs.
You will need 14mm socket or deep socket and a long ratchet (or a breaker bar). Torque for strut bar nuts re-installation is around ~50ft-lbs.
3. Shut down the engine, pop the hood
4. Remove 15A EFI fuse
(based on gen4) from main engine relay/fuse box on passenger side of engine bay
Removing this fuse disables the whole EFI circuit meaning when you turn ignition it will crank, but will NOT activate the igniters (no power) nor the fuel injectors (fuel pump has no power).
Sample picture 1 (gen4):
: The EFI fuse/relay diagram in above pic is based on 2000 Camry Solara SE 2.2L 5S-FE California specs (similar to gen4.5 Camry 2.2L) - mentioned EFI 15A fuse (it was a small ATM size blue color 15A mark) spot was circled in RED.
Sample pictures 2 & 3 (gen3):
The box circled in BLACK is what contains the EFI 15A fuse.
: The EFI fuse/relay diagram in above screen shot is based on 1995 Camry 2.2L 5S-FE California spec (Gen 3.5 Camry). Its the box circled in BLUE and marked in BLUE cross to highlight the fuse that you need to pull out.
5. Jam the throttle wide open
with a large screw driver (just like when cleaning TB & IAC)
This is necessary to make sure there is enough air flow on cars with Cruise Control when depressing the gas pedal to floor may not always fully open the throttle plate.
Sample picture can be found here in this DIY thread:
How to: Cleaning Throttle Body -4 Cylinder Engines- With Pictures
6. Remove quickly ALL spark plug wires and spark plugs
7. Install compression gauge
fitting into cylinder #1 - it doesn't have to be super tight finger tight is fine. Place the gauge on windshield so you can see the compression reading while cranking.
8. Go to cabin and crank the engine for 3-4 seconds
(no longer than 5 seconds) - needle on gauge should jump up at least 4 times. other way of counting is listening to engine revolutions, it should be no more than 5-6 revs.
Another comment on this one was that you keep cranking until the needle max's out. Closed throttle will just take longer to max needle, but open throttle saves battery/starter.
write down the result.
9. Repeat #7 & #8 for the rest of cylinders.
Before you start removing the tester's fitting from spark plug hole, remember to release the pressure by holding the button on a side of a gauge!
Also the gauge I linked has good and solid (extra long so you can easily put gauge on windshield) rubber hose for easy (de)installation and quick disconnect fitting between gauge and rubber hose.
Now about the numbers
Per Toyota specs normal reading on all cylinders should stay withing 175psi or more (pounds/lbs per square inch)
The lowest number you can get (while car is still drivable) should be no less than 142psi.
There is no maximum.
There should also be no more than a 14psi difference between each cylinder.
If you notice one of cylinders with HIGHER compression than others that usually points to a carbon deposits build up in it (try sea foam treatment or switch to synthetic oil) and/or a worn cylinder or piston ring.
If you notice one of cylinders with LOWER compression than others that may point to a leaky/burnt valve above it (do a valve clearance check) or again worn piston ring.
if you notice one or two cylinders LOWER than the others, squirt some engine oil down the spark plug tube (with plug removed of course). Re-test. If the number comes up, you need new rings. If not, it's probably a stuck valve.
If you ran the test right and still notice unusually LOWER than normal compression on some or all cylinders it may point to a bad head gasket.
Basically, based on your results you need to figure out the baseline from which you judge whatever is higher than the "normal" rest or lower then the "normal" rest.
More info on compression results interpretation can be found here:
Hope it helps all people who has never done this test before and would like to perform it right and get a set of comparable results.
Any comments appreciated.
If you screw up something or hurt yourself…that’s your fault. Neither myself nor TN are responsible for any injury, damage, or even death caused by this DIY.