DIY: Compression Test! Lots of pics

[20civic07]

first of all, i would say, GIVE ME MUCH IMAGINARY REP! :P lol no more rep

OH NO OVERREVVED? Do this compression test. Cost was $30 + a bit of time.
I am not responsible for anything you do to your car or any problems that occur because of reading my post. I am merely posting up information regarding my experience to the subject.

TOOLS REQUIRED: 12 mm socket, two 10 mm socket, an extension rod, and a socket wrench, and a panel popper! (not too many people have)

but i would like to say that this site is very awesome, from most of the mods to some of the members. some members are just completely idiots, but learning from this website they go from nubs to nubs who learned stuff to tuners :P

here is your DIY compression test! it will take longer the first time around, as taking the cowl is a pain in the as*.

FIRST! turn the windshield wiper on until it is at its highest position, then turn off the car and take out the key!



Pop this cover off next it is right by the base of the wiper arm.



then once both covers are popped off, pop this off it is right near where you popped the previous cover



after that, you can start to remove the plastic cover.



this is what it looks like popped off.. the tabs look like this and there are 6 clips total.




once it pops off disconnect the windshield fluid hose



grab your 10mm socket, 12mm socket, your extension rod (haha very funny) and your socket wrench



start taking out these screws on both sides of the car ( i already took out the 10mm one.. ) there are TWO 12 mm bolts, and TWO 10mm bolts. the 12mm bolts are next to each other, the 10mm bolts are apart, one is further inside (seen in next pic) and the other one is the one that i took off)





dont forget the one in the middle of the metal plate it is a 10mm. ( it is the one on the left )



once that is done, you should now be able to take out the metal plate preventing you from working on the spark plug cover.



now, you can get access to the spark plug cover, take the ones in the YELLOW out first, then take the ones in the RED out at the SAME TIME. loosen first, get two 10mm sockets and twist with hand.




then disconnect the coil pack connectors and move it out of the way




remove these two bolt bolting 2/4 of the coil packs to the valve cover



now get your spark plug removal socket handy with an extension and take out the spark plugs



once taken out, pop this fuse box cover open and remove NUMBER 11 and 19 both are 15 AMPs as shown in picture 3 below (circled in red). i am not 100% of this as i do not have the manual. I have read by taking out the FI fuses i am fine. I have done this 3 times now and no problems yet. use the white fuse removal tool on the other side of your fuse box cover as pictured in picture number 2 below

1
2

3


once that is done, connect your compression tester to ONE of the cylinders, and hand tighten.


DONT FORGET YOUR TOOLS IF YOU LEFT THEM !!! lol


once tightened, and all the spark plugs removed along with fuse 11 and 19, put your key in the ignition and crank the car 10 times. have someone hold the compression tester upright to get a better reading. it will be a slow cranking of the engine when you turn the key. read the gauge, and repeat with remaining 3 cylinders.

[chugiboi]

Thank for the DIY, REP+

[eugenekim.net]

great job

[Whocares05050]

So what were your numbers in all 4 ?

[20civic07]

183,185,185,181

although not sure if this is healthy, manual says 135 +- 28 psi. so i am taking it to the dealership tomorrow. one of the techs said that it should be around 175ish but it's odd that this car is 135. so i am talking to their head tech tomorrow morning.

[Whocares05050]

Originally Posted by 20civic07

183,185,185,181

not bad at all. very consitant. whats the numbers suppose to be by the book?

[Whocares05050]

Ah, ok. maybe 135 for an r18, bu no way that low on 11:0 compression motor. lol

[20civic07]

Originally Posted by 20civic07

...manual says 135 +- 28 psi. ...

r18 supposed to be 125 +-28...

[Zeuceone]

.....

[20civic07]

i dont understand it either.. either honda screwed up or my engine is jacked up because i doubt many of them have done compression tests yet...

[blownnbp]

Originally Posted by 20civic07

183,185,185,181

although not sure if this is healthy, manual says 135 +- 28 psi. so i am taking it to the dealership tomorrow. one of the techs said that it should be around 175ish but it's odd that this car is 135. so i am talking to their head tech tomorrow morning.

your car is fine why are you taking it in? your numbers show a healthy engine.

[GeezerSi]

Excellent DIY!

[hondaonchrome]

This must be stickied............
thumb:

[rotor_powerd]

Originally Posted by Whocares05050

Ah, ok. maybe 135 for an r18, bu no way that low on 11:0 compression motor. lol

Compression ratio doesn't really affect compression test readings.


Your numbers are good. The biggest thing with a compression check is consistency, not necessarily how high the numbers are. As close as all of yours are together, you are fine.

[peenoySI]

yea dont waste your time bringing it in...and you know why not many ppl have compression tested there car? because the cars only been out since 06

[20civic07]

biggest pain is taking out the cowl... t'is all and most people are afraid of cranking the car with no spark plugs i would assume... the same as changing suspension or brake stuff... if something wrong happens... it's costly...

[ryker]

Originally Posted by rotor_powerd

Compression ratio doesn't really affect compression test readings.


:

My race/street bike with 13:1 compression puts out 220psi on cranking pressure.

[ryker]

FYI: some people advise placing the battery on a high quality charger so each test will have the same voltages.

Also there are two different test you can do. Cranking pressure test (what was done) and a leakdown pressure test (requires an aircompressor).

[SeverianB]

Looks good to me, I wouldn't worry about it. When you are burning a quart of oil every 300 miles, then become concerned.

BTW nice Visual FAQ. Sucks so much junk needs to come off to get to the spark plugs...at least it's not a Subaru. Flat-4 FTL when it comes to accessing plugs.

[rotor_powerd]

Originally Posted by ryker

My race/street bike with 13:1 compression puts out 220psi on cranking pressure.

I've seen a 8.5:1 VR6 put out 210 PSI in more than 1 cylinder.