hey,

i did a compression test on my 2000 SI the other day and came up with these numbers all four were around 180-182.. I cranked the engine five times and all four of them got up around that number and stayed. I even did it at WOT. Do those numbers seem a little low? The car has like 47,000 miles on it. I just put a Greddy 18G Kit on it just recently. The kit hasnt been on the car for no more than 200 miles. I thought the B16 was up around 200-210? Is this because of the mileage or more of a problem..??

 

Around 200 seems a bit Closer to normal, When I Checked compression on my old B16a SIR2 engine I had 215 on all four!

Eric

 

was the engine hot when you did this or had it been sitting a while ?

 

I have 71k on my 2000 Civic Si, Ive had the greddy kit on there since 53k, no problems. My last compression check was 195 185 195 210, im happy with those, but i need to get a leak down test just to be sure. You should get a leakdown test too! We always cant go on compression #'s alone.

Hope this helps

Fred

 

i hate to hijack this thread with suck and obsurdely n00b question... but what exactly happens in a leakdown test and how do you get your results etc?

-ryan

 

did you have all the spark plugs in that will matter in the compression

 

Leakdown test .. basically how much air is escaping from each cylinder ...

You want the lowest drop in the percentage. you typically want between 100%-96% The drop in percentage is the amount of air you are losing. for example 100% means there are no leaks. 98% means 2% of the air is escaping the cyclinder tested. anything more than 4-6% is a big loose and you want to look into it. This is coming of the top of my head.

- Fred

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gzrmoto &raquo;</TD></TR><TR><TD CLASS="quote">did you have all the spark plugs in that will matter in the compression</TD></TR></TABLE>

I dont think it matters, as long as no fuel is going to the cylinder .. i usually unplug the injectors or pull out the fuse (I forgot which one .. 7.5 AMP I think EFI??). I just take each plug out as I go to each cylinder.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tegasaurus &raquo;</TD></TR><TR><TD CLASS="quote">i hate to hijack this thread with suck and obsurdely n00b question... but what exactly happens in a leakdown test and how do you get your results etc?

-ryan</TD></TR></TABLE>

Damm Im a mess today, The best leakdown testers use two gages. One monitors the supply pressure (usually set to 100 PSI). The other monitors the cylinder being tested. Leakdown tests are the BEST way to evaluate cylinder sealing.

 

i took all the plugs out and popped the distrubtor cap off and unplugged the 15 amp fuse under the car and then did the test. I also had just got done driving the car about 20 miles or so.. I had to let it sit for awhile because it was still hot from driving plus it was freaking raining outside so I had to wait a bit longer.. I say it was about 30-45 minutes before I actually got to do the test.. Im betting that was probably why it was low to begin with.

 

and remember, the 1st puff should be at least 50% of what the final reading is, if its not this indicates worn piston rings