Expert: Sean Halliday - 4/9/2007

Question
QUESTION: I drive a 2001 mercury grand marquis 4.6 8 cylinder with 45k miles. she starts up ok but when put in gear a small hesitation occurs. This is more noticeable when the outside temperature gets below freezing. Any suggestions would be appreciated. Thanks
ANSWER: MAF sensor or MAP sensor and also the car may need a tune up such as the air/fuel filters,plugs,wires and look at your EGR valve to make sure its working.I have heard of people having cold problems and some have got a block heater which are pretty cheap and no more problems.

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QUESTION: could the problem be corrected by cleaning the throttle body of carbon build up? If so would you please take me through the steps to do this. thanks again

Answer
I wouldnt think there would be much build up but if you want to clean it its pretty easy.Remove the rubber boot with the air filter and spray some cleaner inside the air way.Look inside for build up and dont use too much spray.I think the cause is the cold air because this car has a heated MAF sensor and may need to let idle before you drive it too eliminate the hesitation .