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Q: Need to know if it's the engine. Misfiring, horrible gas mileage

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My car ran hot one day (the gauge didn't move so I didn't know) so the water coolant outlet popped off, I replaced it and it would only go 25 mph. Why is that? Before that though, my car had trouble starting sometimes and smelled funny, I think the AC was leaking or something. That's when it started running rough and then misfiring. Someone told me motor needs to be replaced, but I had someone look at it and he said I need to clean out my lines and get a new fuel filter, and a tune up. Could it possibly be the oxygen sensor?

My car has 173000 miles.
My car has an automatic transmission.

Hi there, thanks for writing in. There are a few items in your question that lead me to believe you’ve got a cooling system problem that should be diagnosed and repaired as soon as possible. First, if you’re smelling liquid or like rain, it’s coolant leaking, not the AC. This could be caused by multiple sources ranging from the heater core coolant lines, thermostat, radiator cap, or water pump to name a few. If the vehicle is driving only 25 mph, it’s probably due to your vehicle going in to what’s called "limp mode" which is a warning caused by something wrong with the transmission. Your best bet is to contact one of our local mechanics to complete a car is running hotter than usual inspection, so they can pinpoint the source of your issues and reduce the guess work. Hope this helps and best of luck!

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