why is there no compression in one of the cylinders,my mechanic tells me theres no compression in cylinder number 4 in my renault megane 1.6 dynamique 2006,how big or expensive may this be for me please?

susan shaw, April 2013

thank you,the mechanic is taking a closer look tomorrow and hes hoping its the injector thats at fault, iv only had the car a few months so fingers crossed its not a huge bill

susan shaw, April 2013

the cylinder head will probably need to come off to see exactly what is causing your problem,if he puts some engine oil into cylinder before another test and the reading improves then suspect rings,also you can get small cameras now to check combustion chamber for a look at valves/cracks etc but no matter what the head will need to be removed to repair

cdc, April 2013