Jamesray8686

So I bought a 97 Honda Civic for 500 bucks when the guy sold it to me he said cylinder one was missing firing. So after I bought it I replaced the spark plugs and it started running fine . Then a few days later I was driving on the freeway and the a big white smoke came out my top radiator hose busted. I replaced and filled my coolant . Now the car has a rough idle and puts in first gear then after u get it up then it starts driving better but when I shut the car off the motor is super hot and the temp gauge goes from cold to middle temp really fast what's the solution?

As Colin mentioned do a coolant system bleed. Also, it sounds like the thermostat is stuck partially closed and on it's way to completely failing. Since you just purchased and may not have service records installing a new thermostat is probably just good maintenance at this point. Another thing to check is all heater and radiator hoses...especially the heater hose that is directly under the distributor. The distributor O-rings on these engines are known to be a source of oil leaks and leaking, hot oil deteriorates rubber coolant hoses.

To bleed coolant system of air:
* Put front of car on jackstands highest setting
* Set climate control to max heat, fan off
* Top off coolant in radiator and reservoir
* Let engine idle with radiator cap off (use spill-proof funnel in radiator neck , if desired)
* Idle engine until radiator fan turns on twice and top up coolant as needed during process..do not let coolant level go lower than radiator neck.

Bubbles in coolant should progressively get smaller to a point of almost non-existent during bleed completion.

Also, remove and clean IACV + gasket screen with brake clean spray.
Clean throttle body with a toothbrush and throttle body (only) spray.

Colin42

did you bleed the air out of the cooling system?

try doing an idle relearn, or maybe the iacv is sticking

Wankenstein

As Colin mentioned do a coolant system bleed. Also, it sounds like the thermostat is stuck partially closed and on it's way to completely failing. Since you just purchased and may not have service records installing a new thermostat is probably just good maintenance at this point. Another thing to check is all heater and radiator hoses...especially the heater hose that is directly under the distributor. The distributor O-rings on these engines are known to be a source of oil leaks and leaking, hot oil deteriorates rubber coolant hoses.

To bleed coolant system of air:
* Put front of car on jackstands highest setting
* Set climate control to max heat, fan off
* Top off coolant in radiator and reservoir
* Let engine idle with radiator cap off (use spill-proof funnel in radiator neck , if desired)
* Idle engine until radiator fan turns on twice and top up coolant as needed during process..do not let coolant level go lower than radiator neck.

Bubbles in coolant should progressively get smaller to a point of almost non-existent during bleed completion.

Also, remove and clean IACV + gasket screen with brake clean spray.
Clean throttle body with a toothbrush and throttle body (only) spray.

Jamesray8686

what is an idle relearn?

Wankenstein

* With engine off disconnect only the ground terminal from the negative post of battery
* Turn headlights on and tap brake pedal a few times to discharge and residual voltage
* After discharging residual turn off all electronics in (ex: headlights, radio,dashlight, domelight, etc..)
* Reconnect the negative terminal, start engine and let idle until coolant fan engages twice (roughly 15 to 20 minutes). Do not rev engine..idle only while all electronics are still off.

The ECU reset/idle relearn is exactly as it states: the engine relearns base idle.