Thread: Compression Test

Tweet

i did a Compression test. on all the Cylinders. they all averaged around 170Psi. but i had 1 of the Cylinders. Keep shooting Up with every Click of the ignition does that have something to do with the Lobes. or do i gotta take of the heads off? i hope its just the Lobes. cuz the Cylinder that is Not working is the Excaust. hopefully its just something to do with that. or i just gave myself a shitload of more work

A friend said install. the Cam and lifters. and Crank the Motor. to see if the Rocker arms are goin Up and Down like they used to. let me know what ya think!

Camarocanada

Yeah I don't get what your saying either. Around 150-170 sounds right (at least that is what I am told my 302 is supposed to be at.) Give us more info and I will bet you a million dollars Denny can answer it! heh

Alll The Cylinders Except 1 kept Rising Past 170. the Rest Stayed at 170 it was hitting i let it get to 195 and stopped

Try it like this and tell us what you get,
Before making a compression test, run the engine until it is at normal operating temperature, ensure the batteries are fully charged and the starter system is in good working order, if it does not crank as fast as it should, the compression reading will be low, next blow the dirt from around the spark plugs with compressed air and remove the spark plugs, make sure the choke is closed and hold the throttle open, this is so the pistons can draw in a full charge of air on each intake stroke.

So i Pretty well gotta wait till after i install the New cam. and lifters. cuz the hole top of the motor Is off was just hoping to get and Info on what casses that. i was hoping it was. the Cam and Lobes that caused it.

Just to add on this real fast. Can I rent a compression tester from Auto Zone does anyone know? The shop doesn't have my right size fitting and I wont be able to have access to it after this week since I graduate and no more cars or nothing allowed in the shop now so I am too late.
Sorry to get off topic here real quick but though I'd ask while on this subject. Oh viking, thanks for the info man I will be sure to use that when doing my truck.

Auto Zone rents tools


He he, they sould have one, such a great diagnostic tool.

Buy 1 for keeps, they run around 20 bucks. you coul rent 1 but it would probably cost a 5 buck or somthing deposit.

20 bucks? Hell Matt, I didn't think it would be that cheap. Well I have to order a few thousand dollars worth of tools for JUST auto tech class for college this summer and then a few thousand for auto body so I will order a Matco one with my discount and all I guess. Might as well get one since I will need it later on down the road probably. heh.

Yeah maybe I should see what 20 dollar one your talking about. The one from Matco is 139 and with my discount I get I think only 35% off on that one since it's a smaller item.

Part number SUM-900009, $21.99 with 14 & 18 mm adapters....

http://www.summitracing.com/

20 bucks? Hmmmm I spent considerably more than that. Oh well it looks nice

If you are going to rent or buy something, then get a leak down tester instead of a compression tester. When used properly it will tell you a heck of a lot more about your engine then a compression tester could ever do.

Thanks Dave....
Summit # SUM-900010 $69.95

Dave, Denny and Tech, thanks a lot for all the info guys! I don't know how to read the leak down test. On my 302 what should it run or stay at then to know how good my rings and everything are holding? Reason I wanna know this is because the guy I bought this from never fixed this milage gauge or trip (whatever one you wanna call it haha) and doesn't know how many miles are on the motor. I would really like to know because if it's not great and will look like I need a rebuild sometime in the next few months then I need to save money ahead of time.