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Q: Car runs rough after it heats up.

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I have replace everything on my car except the emc My car will start up normal. I can drive it on the highway with no problems once it heats up. I can stop at a red light and it runs so ruff it misses really bad. I can give her a little extra gas at the light and she will run fine with a little rattle in the engine and the rattle sounds like like a bearing. The A/c works perfect. Temperature gage works. Every thing works in the car. Other than that she's perfect. I have replaced wires sparks plugs o2 sensor and air filter. We even disconnected the tork converter. Just in case it was clogged. Every thing I have done to it changes nothing. I get 32 miles to the gallon of gas. The only thing that don't work on my car is the driver side door window won't roll down. Please help and thank you. I can afford to take her to the shop since everything has been replaced. Thanks

My car has 30000 miles.
My car has an automatic transmission.

Hi there. This sounds like there is a minor vacuum leak on the intake. Check the gaskets around the mounting surface of the intake. Check all vacuum lines coming off the intake and see if they are leaking or cracked. If there is no vacuum leaks, then the engine could have a burned valve making a cylinder misfire. Check compression on the cylinders and see if any of the cylinders have a lower compression than the others. If a cylinder is low on compression, then there is a good possibility that a valve is burned and the cylinder head needs repaired. If you need further assistance with your engine running rough at idle, then seek out a professional, such as one from Your Mechanic, to help you.

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