Can some one tell me what the compression should be for 2.6 4 cyl....?and the proper way to do a compress test? want to do the test and can borrow friends tools! would like to know what im dealing with inside engine..lots of mud here would love to go play in it....lol got to love spring

IIRC, it should be around 150ish per cylinder. Main thing to watch for is a cylinder that's way out of line from the others. So, if you get 150-150-150-150 then you're ok. If you get something like 150-150-35-150 then you've got a problem.

Ok, how to do it. Squirt a little oil (not a whole lot) into the cylinder. Screw in the compression guage. With all the spark plugs removed, and the throttle wide open, crank the engine over for a few seconds or until the guage quits moving up.

Richard <img src="/forums/images/graemlins/patriot.gif" alt="" />

And before you start, pull the fuse for the fuel pump and run the engine 'til it stalls. You don't want misted gasoline wafting out of the plug holes when you're cranking your engine. Pulling the fuse will relieve the pressure in the fuel rail.

Just as a reference point, on an engine with 100K miles, and a new head, I recorded appx 170 pounds on each cylinder. It would likely be a bit less than that on an engine with an older head and valves *the 150 that Richard mentioned is probably very reasonable*

Post back with your results!

Or two adjacent cylinders showing lower readings.



I would test first _without_ the oil squirt. Then, if you see a lower reading, by squirting some oil in that cylinder, you can better determine if its a ring / valve / head gasket problem. If the rings are leaky, squirting oil in the cylinder would dramatically increase the compression. If the problem were a valve, or head gasket then there shouldn't be much difference.

ok thank u will try with out oil 1st.... cross my fingers..hope i can get at it today..very curious!! will let u know for sure of the results..

ok done the test...starting at front of engine near fan. compression was with no oil 130-128-45-130......hhmmmm now what? put oil in number 3 the low one and it came up to 75lbs....the 3 plugs that were in the (good) cylinders were all black and dirty....the one in # 3 spot was clean......can any one tell me where to start....get ready to call a tow truck??? any help would be great thank u ! <img src="/forums/images/graemlins/scared.gif" alt="" /> <img src="/forums/images/graemlins/confused.gif" alt="" /> <img src="/forums/images/graemlins/frown.gif" alt="" /> oh yes 283km as far as i know on this engine..

sounds like the valves arent closing in that cylinder. the reason why #3 is clean is because it wasnt being used. gas was escaping before plug could fire.

The valves in 3 are probably closing, but the exhaust valve probably has a great big hole in it.

You could be leaking antifreeze into that one cylinder (unlikely, but possible) and that is why the spark plug is clean.

But, we are really bench racing here. The head has to come off one way or another.

Good Luck,
Michael

Why unlikely ? That's exactly what I found on my #4 cylinder... SPOTLESS! I had been steam cleaning that cylinder for quite a while!

I'd be willing to bet a six pack that if he pressurized that cylinder, there would be a geyser out the radiator fill.

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