My car been shaking bad in when I turn the heat on?

Not sure if you mean the whole car shakes or the engine. If it's the engine, and also has a loss of power associated with it, it could be the ignition module that sits on top of the spark plugs. Also could have the check engine light on and you may hear the cooling fans running also when the car is not warm. I could use a little more info if you can.

Hello, what you just explained in the last part of your paragraph is what's happening to me. 5 months ago I replaced the spark plugs ignition coil and the ignition module on my 2002 Saturn l200 what you explain with the cooling fan is what's happening and it's still losing power and it's shutting off occasionally while driving the service engine soon was on but it's not anymore and the car still has hardly any power

When I start the car it idles at a little under $2,000 RPMs then settles down to about a little bit under a thousand RPMs the engine light was coming on it has loss of power and the cooling fan is coming on 30 seconds after I start it is the timing chain bad because I already replaced spark plugs coil pack and ignition control module.