hi, i have a 91 legacy and last week the upper radiator hose ruptured. i didnt notice right away so it overheated. i changed the hose, topped off the radiator (after it cooled), then it started to backfire and run really rough the next time i drove it. when i'm up to about 35 mph it smooths out some but still backfires. no white smoke from exhaust.. no oil in cooland nor coolant in oil from my observation. any ideas? thank you in advance Dude
CEL light on? Temp. gauge normal? Had a mech. examine it? Mileage? Time since last service? How hot did it get before the engine was shut off?
Carl
i'm not sure what the CEL light is but the vehicle has 176k miles. it was serviced about 8 months ago. the temp gague didnt reach the red mark but it did get pretty high. it never shut off.. it just backfires and runs rough. thanks for your reply
Check engine light
Warped heads come right to mind
I fear the heads warped - it is almost inevitable for an aluminum head on an iron block (which nearly all engines are today) when the coolant is lost. The temperature indication is often falsely low under those conditions because the sensor is no longer in coolant.
A good shadetree test is to start with a cold engine - start the engine, remove the radiator cap and pinch off the tubing to the reservoir, and place the palm of your hand over where the cap goes. If you feel a steadily rising pressure within a couple seconds or (worse) pulsations the head(s) has/have to come off for repair. A shop can do a hydrocarbon test on the coolant to confirm the results before taking the big step.
Mike
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