Hey guys,
I just did a compression test but my numbers came out really low. Not sure If I did it right or if my engine is bad
I'm thinking the first one because the engine runs really good.
I got these numbers
sohc zc
1 155 2 150 3 158 4 160

Heres what I did
Warmed up engine
removed all spark plugs
removed ecu fuse
threaded compresion tester in two three threads only (was afraid it would get stuck
with gas pedal on the floor I cranked the engine for about 4-5 secs each

Theres a small adapter that comes with the tester but I didn't know If I needed it because the hose threaded into the holes without it



I did the test because I thought I had a bent valve.
after I set the timing on the car I hear a small valve tick type noise

One last question; If one of my valves was bent I would have no compression correct?

 

Did you try a wet test?

 

Looks like you did everything right and the numbers aren't to far apart, some compression testers read low, do you have a diff one you can try?your mainly looking for a big difference between cylinders

 

Adjust your valve lash!

 

I did a comprression test with a tester from a different store (renting the testers) when I first put the motor in. All the readings were basically the same.
I found this diy on google
http://www.superhonda.com/forum/f55/...n-test-124194/
I had none of those symptoms that made me put oil into the holes or proceed to a leak down.
Just curious of that noise it makes now that I set the ignition timing
Maybe I'm just paranoid
idles smooth

What is a wet test?

 

make sure to use the adapters to get the true readings, they are in the kit to give you the proper clearances to perforn the test

 

I did that and the noise went away considerably.
Might redo them later on
the nosie is only on acceleration.Sometimes it's not even there so It's probably just me
What are the specs for the sohc zc in regards to compression?

 

Compression numbers are tolerable. On the low side but usable (from what I can remember).

If you had a bent valve you would have really really low numbers on that cylinder.

A wet test will seal the piston rings, so if your numbers don't increase you have an issue somewhere else. Numbers should increase with a wet test.

Checking your valve lash doesn't take long, I would personally check over it.

All of your spark plugs look good?

 

156 psi, should not vary more than 28 psi

 

yep all my plugs are good.
I actually checked my lug nuts and they were a bit loose.
It is a similar sound to that so I hop thats what it is, the sound is only when moving from a stop. not when I rev it in neutral

 

Your numbers are fine. Different testers read differently, it's about the variance between the numbers you get, should be within 10% of each other

 

Just to confirm you need to remove all the spark plugs before doing one cylinder?

I seem to remember friends having done them one at a time but I could be wrong.

If someone could confirm either way That'd be great,Thanks,Matt.

 

Remove all plugs.

 

Thanks Appreciate it.

 

are you saying you didnt thread the hose in all the way? its hard to tighten it enough to get "stuck" without being able to put a wrench on it, my advise, TIGHTEN it, you are performing a COMPRESSION test, the piston is pushing air and space that allows will have air pressure escape.

if you did in fact get it tight and those were your readings in the cylinders at WOT, then i would say that it shows the wear on your motor for its age but its certainly not horrible.

redef90si:

all plugs out or one at a time, doesnt matter, the only affect is that the crankshaft will turn over somewhat easier because the other 3 cylinders are not compressing air in the combustion chamber since the absense of the plugs allows the air to escape.

try turning the motor over with at the crank pully with a wrench, now take the plugs out and turn it, you WILL see the difference. (or feel it rather)

Adjusting Valve clearance is a very good way to quiet down noisey valve ticking, the excessive clearance allows for more travel before the rocker strikes the valve, hence the noise.

Checking valve lash should be done at regular service intervals on ALL HONDA motors.

especially since there isnt a production motor (that i know of) that honda has made without the convenient lock nuts right on the top of the rocker arms.

The tech in me says regular service intervals here, the realist in me says whenever they get noisy.

 

I barely threaded it in, only until it catched because I threaded it finger tight on my first try and it just kept spinning since the hose has a swivel
I adjusted my valves, less tick but the real problem was timing.
My Sears Craftsman Timing light is about 6-10 degrees off.