my 1998 civic started overheating and i found a crack in the top of radiator thinking this was it i bought a new rad still reads hot when in traffic but reads fine when on the freeway ?? looking further i find that the fan was also not coming on so i ran the sender wire to a switch inside and turn it on when in traffic and put in a new thermostat 180 and a cap ?? still overheats at least that is what the gauge says it gets up close to hot on the gauge when it had always ran at about 1/4 up the gauge before ?? does a gauge ever stop working right ?? this car had the timing belt and the waterpump replaced 20000 miles ago the car now has 210000 miles runs great ... the rad i bought has the connection for a trans cooler on the bottom and my car has a 5 speed could this be the problem ?? i have checked for a blown head gasket and find no evidence and i do not lose any fluid ??this is not a hot rod and i drive like an old lady i bought the car new and have taken good care of it and need it to last thanks for any help frankie

 

Make sure the system is completely full. Don't just check in the bottle. With the engine cold, take off the radiator cap and it should be full to the top.

Engine temperature should not vary between freeway and traffic. I doubt that it is a gauge problem.

Are you sure that the fan runs all the time with your switch on? You can just jumper it under the hood so it stays on all the time. Don't leave it like that though, the fan motor will wear out. If the thermal switch is the problem, buy a new one rather than rig stuff.

You can use an automatic radiator in a manual car no problem. Simply don't hook up the transmission cooler. Is this "new" radiator actually a used one? It may be clogged up inside.

 

the rad was brand new and i did fill rad with eng cold and then checked when warm if their is air in the system would it ever come out on its own ??it has been several days now and 200 miles i did not bleed the system but will today and let you know thanks Frankie i have been told to use a honda thermostat 172 would that help any ??it has a 180 now thanks

 

I always used Honda thermostats, it doesn't make any sense to use another brand for a stock motor.