Final generation of the Pontiac Grand Am.

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What would cause my car to accelerate after ive braked?

I drove to work today, when I left home I felt that the car was accelerating by itself. I let it hit 40mph before I pressed the brakes. When I stopped at a stop light the engine sounded like it was revving a little. Then I released the brakes and gave it a little gas and it sped right up and I had to keep tapping the brakes to go the posted 25mph.

Now, it's been having some problems leaking the coolant and we just continually pour in coolant and water...it's getting expensive. What can I do to fix the acceleration problem?

Answered! View the answer I have this problem too

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Skippy722 The exhaust is WHITE! lol yes what exactly would that mean?...and your advice before was a vacuum leak. Fixed! The car doesn't speed up anymore. Thanks for that one!

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White exhaust may clear up since you fixed the vacuum but give it 50 miles. After that if it continues look here: http://www.ehow.com/facts_4965624_white-...

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+one to mayer (can't actually rep you). It definitely sounds like you have a blown head gasket if you keep having to pour coolant into it

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I've got a better one for you today, my car accelerated by itself but I couldn't accelerate by hitting the gas!!!

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Your car either has an electronic or mechanical throttle. Electronic meaning theres a sensor that tells the throttle where is should be, mechanical meaning there's actually a cable that goes from the pedal to the throttle. I would need to know which to accurately help. If it's electronic, make sure the pedal returns all the way to where it should be (pull it up slightly with your foot or hand while the car is off, if it comes up get it checked out, if not you have a glitch in the computer somewhere or a bad sensor). It it's a mechanical link, make sure the throttle (it will be near your intake manifold) moves smoothly and returns to where it's supposed to be... You could also have a vacuum leak somewhere, so check all the hoses coming off the intake manifold and such to make sure they're connected and not split. Sometimes you can't see a small hole in one of the hoses, just an F.Y.I.

As for the leaking coolant, check your radiator and hoses to make sure they're not leaking. If they're fine, then the leak is coming from either the heater core or the block/heads, which is pretty costly. Is your exhaust invisible after the car is warmed up?

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Thanks skippy722. Exhaust is visible when warmed up, began to sputter. I was told it could be the spark plugs....(?)

I think I'll start with looking at the vacuum leak, I did remove the intake. :) Had to get to the thermostat housing. Someone had replaced the thermostat for me and I found that the housing wasn't bolted back on right and there was a gap between the two pieces that meet. Tomorrow we plan on fixing that and replacing the lower hose. Should help with that leak. I'll let you know.

Thanks for you're help! Su

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Remember to use new gaskets when you put everything back together... I'm assuming your exhaust is white in color? You might have to remove the heads and have a look. Thanks for keeping me updated, and it's a pleasure to help :)

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+ very nice and good answer.

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Sue will be eternally grateful.
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