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compression testing specs-help please


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i did a few searches but couldn't find any info on compression testing acceptable or 'normal' ranges for a factory turbo engine. i'm experiencing oil buring while under moderate to full boost but nothing visible under idle or normal driving. i did a compression test; cold engine, from front to rear of engine here are the numbers; 1-151, 2-150, 3-152, 4-149, 5-150, 6-151. all 6 plugs are somewhat black and a bit sooty. the car is an 83 zxt 2+2, k & n filter, 3" [no cat] exhaust, otherwise stock. the chiltons manual says normal is 171, and states that highest to lowest numbers should be within 80% of each other [which they definitely are] but doesn't differentiate between non and turbo. i didn't know if there would be a difference. i'm also feel surging of the turbo [best way i can describe it, cause it doesn't feel like my friends stock turbo which seemed to spool/pull more smoothly] and am suspect that maybe the turbo needs rebuilding. so, with that said any ideas or imput would be helpful.

 

thanks...

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stock compression should be 138-143. The higher compression numbers are probably from carbon build up. You have a quite healthy motor. :)

 

FYI, Mine came up 150 all teh way across. I have a 83, with 170K miles.

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Another test you can do is called a "wet" compression test.

 

Do the dry test as normal, write down your findings. Now, put in a cap full of oil in each cyl, one at a time. Test. wrist down your findings. If the compression raises up more then ~30psi. Your rings are leaking. It shouldn't go up much at all.

 

Note, your car will smoke like no other for a good half hour after this test. It's just burning out that oil.

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