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Q: Temperature gauge is fluctuating, sometimes showing overheating.

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Ok so my temp gauge is fluctuating sometimes alot more then some it goes all the way up to overheat then goes back down to normal i just replaced thermo stat burped the radiator then a little bit ago it started fluctuating alot more and now when i get done driving it theres alot of antifreeze in the overflow tank and i can see that it comes out of the top of it to. Im dreading it might be a blown head gasket since ya know 2.5s go hand and hand with them im just looking for a second opinion.
My car has an automatic transmission.

A: Hey there. There are combustion gas analyze...

Hey there. There are combustion gas analyzers that you can buy and use on a DIY basis for this, but I would have a professional perform the diagnostic, and hopefully find the fault elsewhere (other than head gasket leak). You'll have to check out the entire cooling system before you get to the head gasket. The radiator could be plugged, could have plugged cooling passageways, could have a defective water pump, loose belt issue, collapsed hose, excessive load on the engine due to dragging brakes, underinflated tires, and so forth. Also, if the engine timing is off, the engine running too lean, or the exhaust is plugged (catalytic converter) those conditions can cause the engine to overheat. Quite a number of possibilities have to be looked at. If you want to rule out the worst, certainly you could check for exhaust in the coolant on a DIY basis. For help getting this checked by a professional, I recommend having a certified technician from YourMechanic inspect the overheating concern so that this can be corrected.

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