Sunny6

How accurate is Digital dial.
Can it be replaced the sensor that is could it be wrong?
New LT1 Eng 95 C4 Summit Eng .
Reading 240 Deg.

warrior4jesus

Could be a lot of things. Was it idling, running down the road etc etc. How long since coolant flush, is the coolant any good? What was the temp outside? Sitting in Direct sunlight or shade, breeze no breeze. I recently had my coolant system flushed and it got up to 245 before it finally started going back down. I was in doors it was miserably hot outside and there was no airflow.

billschroeder5842

Check for debris in front of the radiator. Our C4s are vacuum cleaners and a lot of junk (leaves, grass, plastic bags...etc) get stuck between the condenser and the radiator.

Shine a flashlight in between the radiator shroud and see if you have an issue.

DanADaMan

it's "two hot", not "to hot"

Sunny6

washed with hose did not see much come out, but seemed to help.

Sunny6

Both wrong its {TOO HOT!!}
Good Catch!!

billschroeder5842

This is what you are looking for if you have an issue. Washing will do little; you need to vacuum out as the leaves will have no where to go?

ColaBear

Your 86 L98 should not run that hot. If you saw 245 degrees, I would think it needs more than a flush. I would definitely be looking at cleaning out between the radiator and AC condenser and also look into changing the thermostat (as it may be sticking).

The LT1's and 4's are reverse flow engines and they run hotter than the standard Chevy Small Block. Check your users manual to see what your normal operating temperatures should be.

c4cruiser

Are the lower air dams in place and in good condition?? These pieces direct outside air upwards and into the A/C condensor and radiator.

Did you "burp" the cooling system when the engine was installed? An air pocket could be the culprit here. Are both the upper and lower radiator hoses hot to the touch with the engine at operating temp (180 to 205 degrees F) Is the coolant that was used a 50% mix of coolant and water?

Are the cooling fan(s) working properly?