Got a compression test done....

ARed1995GT

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Dec 16, 2004

#1

• Dec 16, 2004

• #1

1 - 110
2 - 105
3 - 105
4 - 100
5 - 100
6 - 110
7 - 105
8 - 105

How much life does my 5.0 have left in it? :[... can i still run it at the track and stuff? how much horsepower do u think i could be losing?

 

DFG 5OH

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Aug 28, 2004

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Dec 16, 2004

#2

• Dec 16, 2004

• #2

how would i do a compression test?

 

Killercanary

The car that set the bar.

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Dec 16, 2004

#3

• Dec 16, 2004

• #3

Well... save your track money for a new shortblock because it looks like you definitely need it. Those are really low. Are you sure you did it right? They are nice and consistent which is good as it appears everything is wearing normally, but they are still very low. My shortblock is TIRED and has lead a HARD life, and I got 145-150psi when I did my test a few months ago. 160-175 seems to be more of the norm.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Dec 16, 2004

#4

• Dec 16, 2004

• #4

I'm with Paul, something had to be done wrong (i mean no disrespect to you ARed). those numbers are very lame, yet too consistant for that much wear (most of the time, not all the pots will wear evenly and so grossly).
i think of compression results like dyno runs - they are nice for tuning and relative comparison, but the absolute numbers are not all that useful.

some things to remember. motor should be warm. ignition disabled, Throttle should be cracked at WOT. all plugs out. battery charged.

if one checks compression on a colder motor, the numbers can be a good bit low.

Matt, a tester can be bought at a parts store for 20 bucks or so (i think). it should include complete instructions (though i hit some of the fine points above).

also, Ared, did you get wet numbers too? that would tell a bit more.

good luck.

 

ARed1995GT

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Dec 17, 2004

#5

• Dec 17, 2004

• #5

i dont know, a shop had done it for me

 

94CobraPace

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Dec 17, 2004

#6

• Dec 17, 2004

• #6

They could have only rotated the engine over 1 time. The consistance of the numbers is a good thing. Do you have a cam, a larger cam can cause low numbers.

 

Venom351R

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Dec 17, 2004

#7

• Dec 17, 2004

• #7

ouch those are not good nubmers if they are accurate. Like Paul said if those are the true numbers Id be putting my money into a new short block. My friend did a half ass compression test on mine before we did the S/C and it came out to about 130's on a cold motor.

 

W

wytstang

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Dec 17, 2004

#8

• Dec 17, 2004

• #8

Do a wet test and see what it says after that.

 

M

mackey

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Dec 17, 2004

#9

• Dec 17, 2004

• #9

Run it at a track... That would be the easiest way to find out if you need one. Those numbers would make your times way off.

 

Rootus

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Dec 17, 2004

#10

• Dec 17, 2004

• #10

Stock heads? If so, those numbers look just fine. You cannot really read much into the absolute value of the number, just the consistency.

Before I did my mods, my 95 had 100-110 on all cylinders. After I put on the AFR 165's, it had 170-175 on all cylinders. No smoke, and after a good tune it puts down over 300 at the wheels.

Dave

 

ARed1995GT

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Dec 17, 2004

#11

• Dec 17, 2004

• #11

good to hear, car still runs strong, gets sideways in 2nd

 

super302

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#12

• Dec 17, 2004

• #12

it's prob. BS, but try some of that 'engine restore' stuff, supposedly restores compression & Performance (according to commercial)

 

Rootus

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#13

• Dec 17, 2004

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super302 said:

it's prob. BS, but try some of that 'engine restore' stuff, supposedly restores compression & Performance (according to commercial)

Click to expand...

Tip: Do not listen to commercials.

 

W

wytstang

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Dec 17, 2004

#14

• Dec 17, 2004

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Rootus said:

Tip: Do not listen to commercials.

Click to expand...

I concur.

 

1105

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Dec 17, 2004

#15

• Dec 17, 2004

• #15

wytstang said:

I concur.

Click to expand...

I second that

how much did the shop end up charging you?

 

cobra dave

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#16

• Dec 17, 2004

• #16

me 2 i mean 3

 

ARed1995GT

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Dec 17, 2004

#17

• Dec 17, 2004

• #17

around $65

 

W

wytstang

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#18

• Dec 17, 2004

• #18

Damn a testor only cost around $25 for the cheap one and 40 dollars for their professional one from autozone and pretty it's simple to do. You may want to pick up their cheap for future use.

 

ARed1995GT

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Dec 17, 2004

#19

• Dec 17, 2004

• #19

yea, i didnt wanna f it up though lol

 

1105

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Dec 17, 2004

#20

• Dec 17, 2004

• #20

whats so hard about it? Take out the spark plug, screw in the tester, turn your fuel pump off, disconect your coil, hold the throttle open, spin the engine over a few times and get your reading.