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L33 compression test, 130 all across

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Old Sep 30, 2015 | 01:29 AM
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Default L33 compression test, 130 all across

Hi guy,
I did a compression test on my L33, all 8 cylinders shows 130. Shouldn't it be higher since L33 has a higher compression ratio? The engine was warm up prior to testing. There are no check engine light, car runs good, doesn't burn any oil, it just seems like these number were a bit on the low side. I spent all day searching n peoples compression test varys from 140-160. Could it be that the motor is on its way out? Thx guys.

Mod are: ls6 cam, ls6 intake, Hooker shorty.
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Old Sep 30, 2015 | 01:35 AM
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Sounds like its trashed. If your in the Houston Texas area, I have a place you can drop it off for scrap before you go get another one.
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Old Sep 30, 2015 | 03:19 AM
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Put a drop or two of oil into the cylinder and see if the compression goes up. If so, its the rings.

Since they are all about the same, it could just be the gauge. Try another gauge. One that's known to be good,
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Old Sep 30, 2015 | 06:26 AM
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Originally Posted by Jimbo1367
Put a drop or two of oil into the cylinder and see if the compression goes up. If so, its the rings.

Since they are all about the same, it could just be the gauge. Try another gauge. One that's known to be good,
X2

It could be the gauge you are using.
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Old Sep 30, 2015 | 12:52 PM
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Thx guys, gonna try a different gauge.
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Old Sep 30, 2015 | 04:37 PM
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Did you have the throttle plate full open during test?
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Old Sep 30, 2015 | 08:02 PM
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Originally Posted by Fierofly
Did you have the throttle plate full open during test?
Also all the plugs out,fully charged battery,next to new starter motor getting full voltage? Too many variables to compare to other's engines,it is more important that all eight cylinders are very close to each other.A leakdown test is what will give you a true indicator of your engine's health or lack of it.
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Old Sep 30, 2015 | 08:26 PM
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Originally Posted by Fierofly
Did you have the throttle plate full open during test?
Didn't do that, will try that n a new tester tomorrow. I think it's just my cheapo harbor freight gauge. You get what you pay for.
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Old Sep 30, 2015 | 08:28 PM
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Originally Posted by tfi racing
Also all the plugs out,fully charged battery,next to new starter motor getting full voltage? Too many variables to compare to other's engines,it is more important that all eight cylinders are very close to each other.A leakdown test is what will give you a true indicator of your engine's health or lack of it.
Thanks
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Old Oct 1, 2015 | 09:46 AM
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Originally Posted by thaiyota
Hi guy,
I did a compression test on my L33, all 8 cylinders shows 130. Shouldn't it be higher since L33 has a higher compression ratio? The engine was warm up prior to testing. There are no check engine light, car runs good, doesn't burn any oil, it just seems like these number were a bit on the low side. I spent all day searching n peoples compression test varys from 140-160. Could it be that the motor is on its way out? Thx guys.

Mod are: ls6 cam, ls6 intake, Hooker shorty.

What year? Was it a true L33 or a newer alum 5.3? Sure you go the cam installed correctly? Did you degree it?

Very odd all cylinders would be low. Tired engines usually don't wear evenly. Usually 1-2 cylinders will be low while the others were high.
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Old Oct 1, 2015 | 06:56 PM
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Originally Posted by Forcefed86
What year? Was it a true L33 or a newer alum 5.3? Sure you go the cam installed correctly? Did you degree it?

Very odd all cylinders would be low. Tired engines usually don't wear evenly. Usually 1-2 cylinders will be low while the others were high.

It's a true L33, 799 head stamp on it, the cam was installed by the previous owner. I have no idea how he does it. I will re-degree the cam since the motor is coming out anyways for a auto swap.

Last edited by thaiyota; Oct 1, 2015 at 07:10 PM.
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Old Oct 1, 2015 | 07:03 PM
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Old Oct 1, 2015 | 07:08 PM
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Old Oct 1, 2015 | 07:14 PM
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Or maybe the motor just hate being in a heavy supra body
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Old Oct 1, 2015 | 08:25 PM
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Hmmm,looks a bit like mine...

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Old Oct 1, 2015 | 08:49 PM
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At the dyno<br/>
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