zach1288

I am going to boost my d16y7 and i ran a compression test today. The numbers were (120)(118)(120)(120) The engine was warm when i did it and i did not have it at WOT? It seems like these numbers are low but they are consistent across all cylinders. Do i have anything to worry about?

ekhatchling

Make sure your foot is on the gas pedal when cranking. I get 180s with engine cold on stock block/head.

zach1288

How many miles are on your engine?

zach1288

bump

zach1288

bump

honisoto

dude, [freak] honda-tech...no one helps around here..

lexluther

Is 180 PSI good.? I did mine last night and they varried from 150-180, and ui thought one had 210.... the car idles smooth, its just not as strong as i thought it should be, even for 106hp.

The_Honda_Guy

(SEARCHED, and this was taken from one of my own posts)

Does nobody here know how to run a compression test or what?

The idea is to remove all the spark plugs, unplug each of the injectors, and block the throttle wide open. Also, make sure the car has been warmed up to operating temperature, otherwise you'll get lower results.

100 PSI is an excellent number for the first compression stroke. The idea is the crank the car over for approximately 4-5 compression strokes and then record the first and last readings. Your first compression stroke should be roughly half of what the final compression should be. Also, you want to watch how fast the car builds compression. If it starts low and slowly builds up, usually that will indicate a piston ring problem, i.e. compression leaking passed the rings. Usually if it's just plain low it's usually a valve problem, i.e. incorrect valve timing, bent valve, bad valve stem seals, etc. If you get low numbers across all 4 cylinders put a tablespoon of oil in each cylinder and crank it again. If the numbers increase drastically it usually means you've got bad rings. If the compression is low on two adjacent cylinders, i.e. 1 and 2, 2 and 3, etc. it usually indicates the head gasket is blown between those two cylinders. If you know how to read the compression gauge accurately it can give you a very good indication of the health of the motor.

Hayne's manual states that 134 PSI is the MINIMUM compression you should see following the instructions I gave you. 180 is the STANDARD (GOOD) number you should see.

Also, a good thing to go along with the compression test is a cooling system test. These two together will give you a very good idea of the overall condition of the engine without performing a much more intricate leak down test.