Skip the auto shop - Our mechanics make house calls

Q: Car runs rough after it heats up.

asked by on

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.

A: Hi there. This sounds like there is a mino...

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Problem with valve injectors.

There quite a few things that will need to be checked. Fuel pressure and fuel pump volume need to be looked at along with a fuel sample. Incorrect fuel pressure or low fuel volume will effect the amount of fuel...

Q: I have a 2014 nissan maxima. It smoking from the exhaust with a blueish gray look. There's no oil leaks on the ground.

Hi there. Check the engine oil level and see how low it is. If the oil is a little low, then the oil is burning in the exhaust system. This is caused by the valve guide seals leaking, the rings...

Q: Overheating

Hello. Heater failure and transmission issues are signaling that the cooling system is having a complete meltdown. Both of these systems depend on the cooling system to work correctly. Typically when the entire system is struggling there is a severe...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...