Actually, the valve spring replacement isn't too bad if you have the right tools. Basically, you need a good compressor a spring compressor (good eyes so you don't lose the retainers) and the new parts. The compressor is attached to the spark plug hole. When compressed air is added to the cylinder, it will hold the valves closed. At that point, using the spring compressor, you can take the retainers off, remove the spring, and replace it.
I would suggest fixing it if the engine was running good before this. A new engine is very expensive and the labor will kill you. Remove the valve cover and take a look. Also, do you know if you have the 3 or 4 valve 5.4L?
Friday, September 2nd, 2011 AT 4:18 AM