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I get on the highway and I start noticing my coolant temp creeping up to like 225F then slowly start dropping to 205F. I get off the highway and stop at the light and the temp goes up to 215F (normal). Then I drive down a side road at like 45MPH and the temp drops down to 199F (also normal).
Why would the temp get so high on the highway but be much lower on a side road? Weather temp is like in the low 50F.
Higher highway temperatures are a result of higher heat load caused by higher engine speeds. I would check the radiator for debris that is caught in the fins of the radiator lowering radiator efficiency.
Higher highway temperatures are a result of higher heat load caused by higher engine speeds. I would check the radiator for debris that is caught in the fins of the radiator lowering radiator efficiency.
I just checked the front of the radiator and I didn't find anything. Maybe there was something there and it fell off when I got off the highway. I'll be hoping on the highway in a few hours. I'll monitor it again.
I was talking about small road debris caught in the fins of the radiator, many owners have purchased a water wand and washed out the debris, and yes occasionally a plastic bag or something similar does get sucked up there.
I was talking about small road debris caught in the fins of the radiator, many owners have purchased a water wand and washed out the debris, and yes occasionally a plastic bag or something similar does get sucked up there.
I did feel some small pebbles when I ran my hand over the radiator.
Don't forget to check BETWEEN the radiator and AC condenser. If you look under the car the first thing you're seeing is the AC condenser. There's about a 1" gap between the condenser and the radiator. It's not uncommon for debris to get in between the two pieces and disrupt airflow.
Don't forget to check BETWEEN the radiator and AC condenser. If you look under the car the first thing you're seeing is the AC condenser. There's about a 1" gap between the condenser and the radiator. It's not uncommon for debris to get in between the two pieces and disrupt airflow.
I can look from the top to see if there is anything in between.
I get on the highway and I start noticing my coolant temp creeping up to like 225F then slowly start dropping to 205F. I get off the highway and stop at the light and the temp goes up to 215F (normal). Then I drive down a side road at like 45MPH and the temp drops down to 199F (also normal).
Why would the temp get so high on the highway but be much lower on a side road? Weather temp is like in the low 50F.
200-225 is considered normal for a c5. The car will tell you is something is wrong.
Mine runs 199 with the fans on constantly and lower air dam. I did replace the thermostat with a stock 186 i should have went with a 160 degree. If the lower air dam isnt on the front it will get hot on all vehicles including f-bodies when on the highway. Mine was missing the lower air dam when i bought the car and going 70-80 mph that car would get hot 235-240 temps. I realized this and put an air dam. The radiator did have a bunch of grass from parking it in the yard i guess after it was sitting for a few months. Im too am interested in the lower air dam screen or cleaning wands.
Clean the a/c condenser and radiator. The radiator is cheap and easy to replace. The a/c condenser not so much. With the radiator out you have complete access to the back of the a/c condenser so clean it good. New radiator is...well...new.
Keep up with your coolant - Dexcool 50/50 changed every 5 years.
Keep a good water pump and thermostat in the system.
Add a water wetting ingredient to the cooling system such as Red Line Water Wetter. It's good for about 5-8 degrees cooler than normal. I had to add this after about 15 years with the same radiator. Since the new radiator I haven't felt the need for it.
Read the article I posted yesterday, it will help you understand your vehicles cooling system; what time it was designed to run at & how the fans are designed to work. You will be surprised at the temps the engine was designed to run at, & it was all done in the name of better emissions.
Also consider taking the vehicle to an SAE mechanic. Better to have a vette running properly than listening to the wrong people & chasing your tail. Often if an engine that isn’t running correctly (timing off. Compression low, etc.) the engine will actually run hotter. Finally consider using “Thermocure” at some point in time, you can find it on Amazon or most auto parts stores. It dissolves the rust that may have built up in your engine block over the decades. I have done this on numerous old (pre-50’s vehicles & have been impressed with the results.
When rust is desolved it turns black with the Thermocure. This tells me it cleaned out a bunch of rust internally. Rust will not transfer heat as well as bare metal & thus will causes your engine to run warmer. It’s a good tool to add into your arsenal in keeping your vette running its best.
Higher than normal highway coolant temp
