Because we are not small enough to go inside our engines and check what’s the situation inside, some tools might help you getting the answer.
The best and easy thing is to make a compression test.
What kind of tool for a compression test ?
The common tool used for this is a simple but effective gauge which monitors the pressure level inside the combustion chamber. Here is a view of the most commonly used type of tool :
To do the test, remove all spark plugs on your engine. Install the gauge on the first cylinder you want to check, and turn the ignition key a few seconds as for starting your car.
IMPORTANT : you need to let your engine turn with the throttle WIDE OPEN. If you don’t do this, you will get a false reading on the gauge.
My DOHC ZC compression test
I made my tests with a tool a little bit different. Pressure is measured the same way, but you can get a small piece of paper with the MAX pressure written on it. This helps having a good reading and keeping track-record of the situation. Here is the result :
The left red line represents the ‘low acceptable value” and the right one represents the “normal value”. I am not in the best situation, but I must say that for such a mileage on the engine (around 200 000 kms) it is not si bad !