Well I was getting bored wating for my ecu and decided I would go ahead and do a compression test while I wait.

The results were 145-150 on all 4.

Is that OK? I am used to seeing upwards of 200-210 with my old JDM engine. What is the H22a4 supposed to read at?

It is very low mileage (65k) and came off an auto so I would assume it should be in damn good shape, but 150 seems pretty low.

 

Yea... that's low.

Did you have your throttle fully open while doing so (gas pedal all the way floored)?

 

Yes I did have WOT. And pulled all the plugs.

Now the thing I wonder is since it hasn't been ran in a couple years would that cause it to read low? I know for sure it sat at least 2 years possibly longer. I was just running some searches and someone had said you should have your car running for a few minutes before you even do a compression test so the oil get distributed throughout the engine or something.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LudeFanatic &raquo;</TD></TR><TR><TD CLASS="quote">Yes I did have WOT. And pulled all the plugs.

Now the thing I wonder is since it hasn't been ran in a couple years would that cause it to read low? I know for sure it sat at least 2 years possibly longer. I was just running some searches and someone had said you should have your car running for a few minutes before you even do a compression test so the oil get distributed throughout the engine or something.</TD></TR></TABLE>

yes, the car should be at operating temp. reason 1, it need oil pressure. reason 2, if your cylinders are cool from sitting all night and you test it. you will get a higher compression number becasue the air is more dense at cooler temps. it might only be a couple PSI higher but its still a flase reading. ill go take a drive and then test my compression for ya, i was looking for something to do today and i need to go get a valve guide driver. give me a couple of hours

 

thanks - do you think this would be the cause of my low numbers?

 

first off, my car is an 01 with an H22a4 as well. well, after driving around for about 30 mins i came back home and checked it. cylinder1-3 all came in at 190 and cyl no 4 read 208 abouts. so i think i need to do a valve adjustment, either that or i bent a valve when i hydrauliced it a few months ago. i also noticed my spark plugs were too hot so i bought a set a step colder. so, your compression does seem to be a bit low.

 

So I shouldn't worry about it till I get it running anyway?

 

it would make sense to me to find out whats wrong while its not running, but that just me.

 

Yea but there may not be anything wrong. This engine hasn't run in over 2 years. That may be the reason for the low numbers. They are even so I am going to assume once it gets running it will register higher.

 

noob question here (puts flame suit on) if you have to get the engine running to operating temperature, how do u test an engine that has been removed? or is that impossible and you have to just inspect the parts and hope its good?

 

Leakdown test

 

I got a question for ya since you sound like you know what your talking about.My h22a4 is in a hatchback and im running a chipped ecu.We did a compression test on my engine and all we did is unplug the cords to the plugs and took on spark plug out at a time and checked it.This was checked after it had been driven for a while so i know it was hot but i didnt have the pedel to the floor when i was cranking it.my compression read a 120 120 120 and 60,the 60 was in cylinder number one.Come to find out i broke the piston ring land on the piston and im replacing that piston.But my question is about my compression being that low.I didnt know till now that i was suppose to do the wot thing.Will that make the number be that low?My email is slofton@srob.com if you can will you please email me there so ill know when i get it.Thanks
seth

 

Those numbers are quite low, probably due to the test not being done at WOT. Do you have any other modifications done such as pistons or cams?

 

i have cold air intake headers exaust i have a 75 shot of nos but i only spayed it 3 times and this happened so im gonna have to tune it

 

you will need to run the motor for a while before checking compression otherwise you WILL get a low reading.

and when checking compression it is not necessary to keep turning the motor over until the gauge stops. you want to turn the motor over the same amount for each cylinder.

for example: turn the motor over 5 times on each cylinder. if all of them are close to eachother (within 15 psi) i wouldnt worry if they read low. if you keep cranking the motor until the guage stops, thats not really helping you because if it takes cylinder #2 three more rotations to make the same reading as cylinder #1 then those cylinders are different even though you got the guage to read the same.

 

i only turned the motor over three times on each cylinder.i just didnt put the pedel to the floor but they would have all been 120 so long as they all the same its ok.its probly not the motor its probly the operator.