Engine compression on a VQ30DE
04-10-2005, 05:29 PM
#1
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Engine compression on a VQ30DE
I have tried searching on this topic and haven't found much. The latest thread on this is a year old! lol
Anyway, I have made it a habit to do a compression test every year when I replace my plugs in the spring. I will be doing a compression test in the next couple of days. I have owned this car for 3 years and ever since I started racing it (about 2.5 years ago) it has started to burn oil. As such, the compression has been declining slowly over the last couple of years that I have tested it.
As per the FSM, 185psi is normal; 142psi is minimum and 14psi is the tolerance.
I am thinking about looking for a lower mileage VQ30 motor with good compression and swapping that in. However when looking at these used motors, I have seen some that are in the ideal 180-185 psi range across all 6 cylinders, and then I have seen some that are 200psi across all 6 cylinders. This would be indicative of carbon build-up if I am not mistaken.
My question is, would a motor that has 200psi across all cylinders be better than a motor that has 185psi across all 6 cylinders?
Anyway, I have made it a habit to do a compression test every year when I replace my plugs in the spring. I will be doing a compression test in the next couple of days. I have owned this car for 3 years and ever since I started racing it (about 2.5 years ago) it has started to burn oil. As such, the compression has been declining slowly over the last couple of years that I have tested it.
As per the FSM, 185psi is normal; 142psi is minimum and 14psi is the tolerance.
I am thinking about looking for a lower mileage VQ30 motor with good compression and swapping that in. However when looking at these used motors, I have seen some that are in the ideal 180-185 psi range across all 6 cylinders, and then I have seen some that are 200psi across all 6 cylinders. This would be indicative of carbon build-up if I am not mistaken.
My question is, would a motor that has 200psi across all cylinders be better than a motor that has 185psi across all 6 cylinders?
04-11-2005, 10:56 PM
#4
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Originally Posted by maximazation
it wont be the same, but its better to have an even amount of psi throughout all 6
Okay let me rephrase my question a little: Is a motor with compression between 200-210 better than an engine with compression between 175-185?
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