The Stovebolt Site Forums The Shop Area Engine Shop is it running hot

i have a 1963 chevy C-10. the engine is a 1979 chevy 350 V8. the temp gauge will get up to 250 (highest i let it get then cut it off) is this running too hot? if it is what can i start out at to get it fixed?
Thanks YC

i would say 250 is too hot. if you know temp is correct then i would check into it. did you leave the orig rad in? can it handle the v8? did you get the fan spacing close enough? just some ideas, good luck. hr

it's running too hot if in fact it's that hot .... start at finding out what your temp guage means when it sez 250, compare with a good thermometer in the rad, or preferably onea the laser thermometers so you don't have to open the rad, check at both sides of the thermostat housing and top/bottom of the rad, see if you have flow and are getting cooling, the gauges on these ol trucks don't always tell the tale

Bill

There are two main causes of hot engines. The first & easiest to fix is the thermostat. These are cheap & are easy to replace. Get one that will fail in the open position. You should be able to replace one of these for less than $20.

If you remove or replace the thermostat & it still runs hot (more than 200 degrees) you have a radiator that needs to be cleaned or poor airflow. Usually if a rad has run water for some period of time scale will build up on the inside & prevent it from cooling.

You can buy a new rad or find a local shop that will boil it off & clean it out. The local shop way is usually cheaper.

my parents have known the people that have owned this truck since it was bought new. the person i got it from chenged engines but it looks like the original radiator. he restored the truck then parked it under a barn and that is where it sat for 23 years. i got it drained the radiator and put new water in it. new hoses. but still used the old thermostat. i guess i need to check to see if it is really a good guage. just by the heat coming off the engine it seems like the guage may be right. can i pull the thermostat out and see if it runs cooler without it in?

Don't remove it completely you need some restriction to give the water time to pick up the heat. just remove the guts and put back the ring and the pyramid piece.

easier to put in a new one than to open it up twice, they're cheap also flush the block while you have it open, there'll be lots of crud settled in the lower passages after that long a sit

Bill

If this engine sat for 23 years make sure you have water flowing. The water pump impeller may have rotted off.