i have a 1997 mazda 626 and it runs fine except for a few things onece the engine warms up i can hear something in the engine knocking i think it is the valves cause i know it is not the pistons i want to find out what can cause the valves to stick and if there is a way to fix it with out removeing the head cause i really don't want to do that unless that is the only way. and when it is idleing and it heats the fan comes on and when it cuts off the car sounds as if it wants to shut off it only shut off once when it was idleinganother thing is that the check engine light wont go off i checked every thing on the engine all the sensors and replaced the ones i could replace and it still wont go off can any one help me with that and only the fan on the right side of the radiator comes on can any one help me with my problems and why is it that the right front window takes so long to come up cause my brother's 1995 626 does that too.

 

With the check engine light, what diagnostic troubleshooting code is set, need this info to help. The one cooling fan running is normal;
the second cooling comes on if running hot or the A/C is on. The slow window issue can be fixed with some spray silicone provided the run channel is in place. Your engine noise have a mechanic check that to many possibility to post.