I got my 300zx a little over a month ago and have been fixing it up since; recently got the 120k maintenance done as well. When changing the spark plugs I did a compression test and am slightly worried about the results:
Cylinder...psi
1............180
2............173
3............180
4............170
5............162
6............170
Piston ring problem on cylinder 5? Should I be worried? What do you think.
Car is a manual '93 300zx NA.
Compression Test Results
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RED_DET
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Re: Compression Test Results
Normally you don't want to see a max variance between cylinders of 14 psi.
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NolimitZ32
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Re: Compression Test Results
AFAIR the manual says max variance 10%, which you are within. If the car isnt acting up I wouldnt worry too much. Do the oil trick and confirm that its your rings and then just drive it.
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300ZXttZMAN
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Re: Compression Test Results
So Nathan, did you ever try the oil trick?
Re: Compression Test Results
What is this oil trick exactly? Could I possibly have a link to another thread regarding it.
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NolimitZ32
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Re: Compression Test Results
the oil trick, is when with the engine fully warmed up you first check the compression per the usual procedure and then go through and pour a couple of capfulls of oil into each cylinder and check the compression again. If the oil has a big impact on the numbers than the cause for your loss of compression is worn rings.