My first thought is have you checked your fan? Some fans spin but not fast enough. Electric fans get weak and direct drive fans have a clutch that gets weak. Another issue is the air dam ( the piece of plastic under you car). Most cars are designed to push air through the radiator if the air dam is missing it might be a problem.
1) ONE THING YOU COULD TRY IS CHANGING THE RADIATOR CAP...IF IT'S BAD THE CAR WILL BOIL OVER AND APPEAR TO BE ALWAYS OVERHEATED WHEN ALL THAT'S REALLY WRONG IS THE LACK OF PROPER BACK PRESSURE DUE TO AN OLD/DEFECTIVE RADIATOR CAP. 2) IF THAT DOESN'T WORK YOU COULD TAKE THE THERMOSTAT OUT AND TRY DRIVING THE CAR WITHOUT IT IN AND SEE IF THE CAR RUNS LONGER BEFORE OVERHEATING...IF IT DOES THEN THE THERMOSTAT IS STICKING. THE THERMOSTAT COULD ALSO BE UPSIDE DOWN...IF IT IS IT WON'T WORK RIGHT. patricklaw1957@yahoo.com You might also check the timing.If it is retarded due to a bad timing chain or needing a tune up this will cause overheating.
White smoke from the exhaust indicates you have a blown head gasket or cracked head. Stop driving the car until this is repaired or you will do serious damage to the engine.
Check your electric cooling fan
Are you sure its the rad? BMW suffered from viscous fan failure. Symptoms were overheating in stationary traffic but ok when driving along.
did you replace radiator hoses i have seen hoses collapse and cause overheating while driving and radiator could be clogged. also did you bleed your cooling system according to owners manual
Did you replace the thermostat, and check the water pump? Does the cooling fan operate as it should? A plugged catalytic converter can cause overheating. If above items check out OK you need to check for leaking head gasket.
Thermostat.
its a 96 caprice already changed the thermostate fans are working Do you have an obvious leak,making the engine short of coolant? If no obvious leaks,the first place to look is the thermostat,these frequently fail shut,so restricting the coolant flow. You don't say what sort of car it is,or if this happens only in traffic (radiator fan not running) or just driving along,thermostat,blocked radiator,cylinder head gasket. Modern cars must have good quality antifreeze mixed to recommendation for good cooling and anti-corrosion.
There are other things at play to keep your engine from overheating and they are cheaper than radiators. First make sure the radiator cooling fan is coming on. Cost to do this "Free" Next you may want to replace the thermostat. It may be stuck closed or partially closed. Cost about $8 and your time. Either of these two will cause overheating and are more likely to be the cause than the radiator. A collapsed radiator hose will cause overheating also but rare. Hope this helps
Low coolant or an inoperative radiator fan.Low coolant or an inoperative radiator fan.
do you have the right thermostat installed if so is it installed the right way
check thermostat and/or water pump