Hi, I drive a 2006 Saturn Ion and after I change my oil I just start hearing a knocking noise in my engine. Now I don't know if it's because of the type oil I used, I switch from using the castrol 5W 30 to a synthetic 5W 30 . The car is also a used car.

Have your motor supports checked. Also the drive shaft could be causing the problem if that knocking is not coming from inside the motor.

Your hearing lifter noise common in most cars in cold weather I have a 2001 sc1 same engine as yours here's how to get rid of that ticking sound go buy a quart of Lucas synthetic motor treatment change your oil and leave it 1 quart low add the Lucas synthetic oil stabilizer within 1 week you will not hear the noise agian reason your hearing the noise is there's no oil at the top of the engine on a cold start oil when cold is thicker hints why your noise in your engine what Lucas does is eliminate the dry start by the way my engine has 288,000 and does not use a drop of oil after you use this product you should use it every oil change you will see your car will thank you regards Chris

bad motor or transmission mount.

Hi, I recently bought a 2005 Saturn Ion and all of a sudden when I accelerate or at least attempt to, I hear "knocking" noise. It gets louder as I press harder on the gas pedal, what does this mean??? Also, my coolant light is on as well, however when we checked the fluids, it was full..will these repairs be pretty costly? And is it even worth getting fixed?

Hi,
1st thing - DO NOT DRIVE as you may be low/out of fluid.

Check both your automatic transmission fluid and your engine oil level. Both should be described in the owner's manual.

GL,
Td

THE WHEEL BEARING IS GOING BAD NEED TO REPLACE IT.

best advice here is to ask a local mechanic to have a look as engine shouldnt have started knocking with teh new oil in unless someone has put tranny fluid into teh engine or something stupid ,the lights for the airbag shouldnt be connected but the oil light ?? Do not drive car untill a mechanic has come around and checked it out for you though as this oil light coming on and knocking noise is serious

Well, longer oil change intervals all insist on enough oil. you cannot just keep going without checking it ROUTINELY.
I am not sure about the "thought I needed more oil" either it measured low or it did not....However, situations like you describe would not usually cause engine damage, and oil would not cause no start. I suspect that something else has happened, and I suggest that you get your vehicle towed to your mechanic, tell him all of the details and have it diagnosed.
Change your oil evey 2,500 to 3000 miles, it is cheap insurance.

Sounds Like A Wheel Bearing Has Failed. ISOLATE it & Replace it

Itmay be a foreign object inside the blower motor, a bar blower motor or your engine is bad, have a technician scan it to be shure.