OKay here are the results. As far as I know its a healthy motor with 61K miles on it. All Mobil 1 oil changes, I've been boosted for about 3 months, no problems.

175 165 175 165

Now I'm happy that I didn't see something like 110/105 but aren't these a little low across the board? I'm not to skilled in this area so if anyone has anything to add -I'm listening. b16a2 with Greddy 18G Turbo kit, stock internals.

Thanks guys!

 

was your trotle wide open when you did the test
look not that bad(steady number) but could be better (stock si should be in the 190-210 range whit stock piston)
do a leakdown test

 

Did you hold the throttle wide open while you were cranking it? Did you have all the plugs pulled? Good to see consistency across the cylinders but the numbers do see a little low. I get ~190 on my B18C1 with 100k miles.

 

Yeah those numbers do seem a little low, but consitent nonetheless
1. was the engine warmed up?
2. did you do it at WOT?

ot: But what boost controller are you using to up to 7psi?

 

Well I got my oil changed at the place I always go to and they guy who I know really well told me he would do it for free .. I don't know cause I had to drop off a BMW and I left just as he did it, butthe car was sitting there for alteast 15 minutes cold and I did see him take out all of the spark plugs and then I had to go.

Maybe I should Just do it myself, I thought this would save me time and yeahit was free

The boost controller, probably the Prof B, but I need funds

 

do it yourself
NOW

 

Iknowwwwww

 

Woah! You do not take all the spark plugs out to do the comrpession test. You take each spark plug out one at a time. You take #4 spark plug out, put the tool in and test cylinder #4. Crank the motor 5-7 times or till the needle doesn't move any more. You then put the spark plug back in #4 and goto #3 and do the same thing. Make sure you disconnect the ecu so the injectors do not get a signal to fire or else you will flood your motor.

 

Numbers also depend on what the guage goes up to...they are not all alike. The variation is in tolerance. Comp. tests are not all that acurate anyways...if you want to know the condition of your motor you need to do a leakdown.

 

OKay guys, good info. So the next question on my mind is how does a compression test differ from a leakdown test, and what exactly is a leakdown test?

Thanks

 

why not? what would it matter? ive always taken all the plugs out at once and never had a problem.

 

A leakdown test sends compressed air into the cylinder, and measures how much air is losed. it may also be able to tell you where the air is leaking out of. This is from my understanding, maybe somebody can expand on this.

-deepsi

 

I take them all out as well. Always seems to work for me...

 

I don't see what difference it makes if you take them all out. As each cylinder is indepedent anyway right?

 

with the plugs out the engine free spins, so you have less pull on the battery
and starting system, plus you don't have to use 5-6 compression strokes
you should only use 3 to 4 max.

there are two types of compression tests, dry and wet. after you check dry
pour a tablespoon of oil into the cylinders that were low, and retest. if the reading
is higher now, you have worn rings, if the reading stays the same, use a CLT
cyl leak down test, which will measure the leak as a percentage at TDC compression of the cylinder that you are testing
with the CLT hooked up use you're ears to find the air leak
pull the oil fill cap=rings"or melted pistions"
listen in tailpipe=leaking exhaust valve
listen in intake manifold= intake valve
pull radiator cap=compression leaking into water jacket
check adjacent cylinders= head gasket in between cyl
or a cracked head cracked cyl wall,
this way you can tell if it is worth taking apart
shhh don't tell anyone, charge them 5$ haha



[Modified by Technician, 7:29 AM 12/24/2002]

 

wow very informative

 

you aint kiddin! nice change from the norm around here.

 

Wow!! Im gonna do this in the morning!!

Damm Joe you knew all this, you just didn't want to type it!

P.S. Where the Heck is Art????

 

nice, I knew about the oil cap just becasue it happened to me once, but the valves and the radiator is definitely good info...

 

yeah but i am too lazy to type it...or go try it...

where is Art? i cant tell you.

 

 

Fred those numbers seem low across the board, as they are saying you should be pulling ~205

Make sure the engine is warm and at operating temp. Make sure you have your throttle wide open. i pull Fuse #15a (its in teh fuse box under the hood) pull plug #4, screw in the tester. crank her over 5 or so times. check the results. repeat for the other three. if you still get bad results, try to get another tester, just to rule out that the tester was bad or inaccurate. if you get the same results, try putting a capful of oil into each cylinder. if your #s go up, then its prolbably your rings. if #s still stay the same, time for a leak down........

 

this is very "un-honda-tech-like"

and i like it a lot

 

Okay guys I just got done doing the test, man those guys must have really sucked
cause I got much better results

Here goes ..

190 180 190 210

I'm much happier. It was simple, thanks for all the help!! I'd say im safe to see 7 psi, but I'll be saving for a rebuild anyways

 

Right after my rebuild w/ 9:1s I got 190 all across the board in my B16A2. If this helps any.