Car heat gauge going over midline where it's never gone

[Schpark]

Check the oil and make sure it is not milky. Would indicate a head gasket issue.

[RAMd®d]

I've run a hose over the cap and radiator to cool it down.

When it remains warm or cooler after the rinse, it should be cool enough. Here's where even a cheapie IR heat gun is handy.

In my experience, if you can squeeze a hose without much pressure (especially the supply hose) it's time to get new hoses.

If you haven't found any drips or puddles on the floor, or don't smell anti-freeze, it's probably just time (or past time) to fill the radiator and reservoir to appropriate levels with 50/50.

You might check your owner's manual for the stated flush/fill intervals. The fluids should be checked on regular intervals. Even without fluid in the reservoir, your car shouldn't be getting warmer than normal, unless it's a small radiator and large reservoir.

[N-OS X-tasy!]

Speedy wrote:
Never use water except in an emergency. Antifreeze is useful required both in hot and cold climates.

FTFY. "Antifreeze" also acts as coolant and is required, not optional.

[N-OS X-tasy!]

Carm wrote:
[quote=Dennis S]
About how long does it need to cool before I can take the radiator cap off?

Squeeze one of the hoses, if the pressure is high it won’t have any give. If it cooled down enough you can squeeze without much pressure on the hose.
Plus if you burn yourself grabbing the hose, you'll know it's too soon to remove the cap.

[Racer X]

N-OS X-tasy! wrote:
[quote=Speedy]
Never use water except in an emergency. Antifreeze is useful required both in hot and cold climates.

FTFY. "Antifreeze" also acts as coolant and is required, not optional.
Bzzzzt! Wrong answer. Antifreeze raises the boiling point of the liquid over straight water, but so does running the system pressurized. If you run the vehicle with a pressurized sealed system, and use the appropriate water pump lubricant/anti corrosion additives, you don't need glycol.

Adding glycol to the water actually retards the flow of heat from the metal to the liquid because it has higher viscosity and poorer heat transfer. Seriously. There are actually water additives that are water pump lubricants, anti corrosion chemical mixes and something magical that lower viscosity and improves heat transfer that will actually lower engine coolant temp @10 degrees, and significantly cooler heads around the exhaust valves and ports because of the more efficient thermal transfer. My big Buick gets by just fine with a 500 HP motor, and the standard 3 row radiator because I have it filled with double dose of Redline Watter wetter. Runs close to 20 degrees cooler than with 50/50, and far less detonation because the exhaust valves run cooler. Kept in an enclosed garage that doesn't freeze. You can add Water wetter to 50/50, but its effects aren't as drastic, but will still help with a heavy truck, boat or RV under heavy loads.

Now, for practical every day use, glycol/water mix is the best compromise for the vast majority of the population.

Know your basic thermodynamics and fluidics!

[cbelt3]

Excellent advice above. I will simply add the usual cbelt3 disaster story to indicate why you should NEVER OPEN THE RADIATOR CAP until it's cool.

[spoiler=OK, I warned you. Epic tale of stupidity, pain, hospital visit, and amusement enclosed..]
We owned an '82 Olds 98. Land Yacht, huuge V8 engine. Mrs. cbelt3 loved it, driving it gave her her tag line "I was born to drive a big car fast in the left lane." And one summer day we drove our 2 year old daughter to my inlaws house, about a 3 hour trip. And sure enough, the Oldsmobile started overheating (thermostat was the culprit). Stopped a few times to add water to the overflow tank so it would not run dry, and let it cool down.

And once we arrived at the house, my wife and daughter went inside. I turned on the hose (nice cold well water) and watered down the hissing radiator. And noticed that the radiator cap was wobbling. Hmmm. I took a rag and reached over to tighten it and.. WHOOSH ! The cap failed, soaring past my head. And a gout of green superheated steam/ethlyene glycol erupted straight at my face at incredible speed. I closed my eyes and mouth and started moving away and it just scorched me, dripping down into my shirt.

I grabbed the hose and flooded my head and face and upper body with 50 degree well water. And then the pain it me, and I started screaming. Ho leeeee.... I'd never had a burn that bad.

An ambulance was called. The EMT's congratulated me on using the water to treat the area. The ER doc surveyed the injury and prescribed a lotion to help keep the mostly first degree, some second degree, and only a couple of small patches of third degree burned areas from getting infected. And properly antibioticized, dosed with pain medication, and lotioned up with this magic stuff, my wife took me home.

Recovery took a week or so. And the lotion, as it happens, contained silver (anti bacteria I assume). And when it was exposed to UV from the sun, it turned blue and smelled kind of bad.

So for my recovery period, my daughter's name for me was "Papa Stinky Smurf". miley-laughing001:

[/spoiler]

[N-OS X-tasy!]

Racer X wrote:
[quote=N-OS X-tasy!]
[quote=Speedy]
Never use water except in an emergency. Antifreeze is useful required both in hot and cold climates.

FTFY. "Antifreeze" also acts as coolant and is required, not optional.
Bzzzzt! Wrong answer. Antifreeze raises the boiling point of the liquid over straight water, but so does running the system pressurized. If you run the vehicle with a pressurized sealed system, and use the appropriate water pump lubricant/anti corrosion additives, you don't need glycol.

Adding glycol to the water actually retards the flow of heat from the metal to the liquid because it has higher viscosity and poorer heat transfer. Seriously. There are actually water additives that are water pump lubricants, anti corrosion chemical mixes and something magical that lower viscosity and improves heat transfer that will actually lower engine coolant temp @10 degrees, and significantly cooler heads around the exhaust valves and ports because of the more efficient thermal transfer. My big Buick gets by just fine with a 500 HP motor, and the standard 3 row radiator because I have it filled with double dose of Redline Watter wetter. Runs close to 20 degrees cooler than with 50/50, and far less detonation because the exhaust valves run cooler. Kept in an enclosed garage that doesn't freeze. You can add Water wetter to 50/50, but its effects aren't as drastic, but will still help with a heavy truck, boat or RV under heavy loads.

Now, for practical every day use, glycol/water mix is the best compromise for the vast majority of the population.

Know your basic thermodynamics and fluidics!

[Racer X]

My brother took off a rad cap when he shouldn't, got 2nd and 3rd degree burns on his chest, neck and right armpit.

Any any vehicle with a cap on the radiator, I immediately replace them with a lever lock pressure release cap. Can't remove the cap without lifting the lever, which vents the pressure/liquid to the overflow tank.

Also, in a pinch, if you have a small pressure leak, you can run with the cap on, but lever lifted, so the fluid stays in, but won't build pressure. You can still get home most of the time.

[Gareth]

N-OS X-tasy! wrote:

Which, as I recently discovered, is like $20/gallon at an auto parts store, but $9/gallon at Walmart.

[N-OS X-tasy!]

Gareth wrote:
[quote=N-OS X-tasy!]

Which, as I recently discovered, is like $20/gallon at an auto parts store, but $9/gallon at Walmart.
NEVER buy fluids at an auto parts store except in an emergency.

Walmart is substantially cheaper on many auto maintenance items, for sure. My local Walmart sells the 5-quart bottle of Pennzoil Platinum 5W-30 synthetic oil I use in my car for approximate $23, WAY cheaper than I can find it anywhere else.