Compression

2007 VOLKSWAGEN EOS
120,000 MILES • 2.0L • 4 CYL • TURBO • 2WD • AUTOMATIC
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THORINENA LEWIS
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After i had valve job done at shop I have good compression in 1 and 3 180 psi. 2 has 30 psi and 4 has none. Could it be off time a little or did the machine shop mess up somewhere? I am going to pull head and inspect it again, but before I do going to check timing again.
May 4, 2019 at 11:12 PM
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SCGRANTURISMO
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Hello,

You should definitely have compression in all your cylinders. If your timing was off causing the valves to open at the wrong time, they would be off on all cylinders, not just two. I would go back to the machine shop and have them make this right. A good way to check to see if this is because of your piston rings or not is to do a compression test and record the compression in each cylinder. On the cylinders with low compression pour a teaspoon of engine oil into that cylinder through the spark plug hole. Run another compression test. If the compression in that cylinder came up then the piston rings for that cylinder are bad. If not, then it's probably the in the valve train. I have included a few links for you to go to below:

https://www.2carpros.com/articles/symptoms-of-low-compression
https://www.2carpros.com/articles/the-reasons-for-low-compression
https://www.2carpros.com/articles/how-to-test-engine-compression

Please go through these guides and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros
May 5, 2019 at 1:43 AM