Originally Posted by apurv146
Hi jesrani and Other fellows,
I also have sx4 2009 model and running it on CNG since last 3 years. Now, it's getting shut down when I slow down the car or when put off my leg from accelerator. This is happening in both CNG and petrol. Since last one month I am running car only on petrol. When I shown my car to authorized service station where I used to go for car service, they are saying that engine head needs to be replaced and for this coast is around 40K to 45K. They are saying that this happened due to CNG and valve of 3rd cylinder (4 cylinder car) is damaged or leaked.
So, my question is should I go for engine head replacement and invest this much money for this car or just sell it out?
How much more will this car work after engine head replacement (i.e. How many kilometers or years ?) .
Will it work with CNG as well after replacement or I have to run it on petrol only?
jesrani : Have you opt for engine replacement? Was your car ran properly on CNG after head replacement or only in petrol? Any other problems you faced after engine head replacement?
If only one cylinder is the issue, whole engine will not stop at low speeds.
Just try removing spark plug wire of that cylinder and see what happens in idling,
Report back what happens.
As service guys says valve seals have gone, does exhaust smoke whitish? Or whitish blue tint?
Rev the car to check smoke!
How did service guys come to know 3rd cylinder valve is the issue?
Did they open the head?
Did they charge you anything for checking it?
Means new gasket? Filling paste? Labour?
If not they have blindly told you,
Just because replacing new head will solve the issue,which is simple for them.
As car runs, i suspect its a minor issue
Tell them to chk whether knock sensor is working or faulty!
Tell them to chk continuity between sensor wire to ecu.
Is your engine light glowing after you start your car?
Please do a compression test in all cylinders to check whether problem is related to engine.
If every thing is fine, you are free , its some Minor thing making issues.
By just doing a cylinder compression test will narrow the issue! Do it first