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Overheated and Lost Coolant

So last week, my battery died. I replaced the battery. The very next day, driving home, my “check guages” light came on, and the car temp guage was pegged to the red at 260. I was right by my house, so I pulled in my driveway and stopped. All the fluid had come out of the radiator (in the road) and it was bone dry. I’ve been told this could be caused by a bad thermostat, or a slow leak, or something worse. What’s the most likely scenario?



I filled it up with plain water, have been checking for leaks for days (haven’t seen any, for the record) and only driving back and forth to work, which is a 5 minute drive. Nothing has gone wrong since, it seems perfectly normal.

Aren’t you lucky…Do you live where freezing temperatures might occur? Have your cooling system pressure tested as soon as possible to find the leak (THERE IS A LEAK)

Please post year, make, model mileage. You will get better answers

Oh, sorry, I was half asleep and forgot:

1998 Oldsmobile Bravada - in teh deep south where it thinks about freezing once every other year, so water in it right now isn’t an issue.

Yes it is a major issue. This engine is probably made of aluminum. It at least has a good deal of aluminum in it. Especially the cylinder heads. Straight water will react with the metal, and corrode the crap out of it. Aluminum is much more reactive than iron or steel, and corrodes much faster. Once your sure the engine is OK, you need to drain out the plain water and put in the proper coolant mixture. Most coolants today have the proper anti-corrosion protection for the aluminum in your engine.

That was my plan, I have a fluid evacuator I was goign to use, I just first and foremost need to figure out what’s up with it having lost all of it’s fluid in the first place.

There’s no obvious leaks that I can find, it seems to have all come out the drainage hose from the overflow tank and through the sealed cap via the pressure release. The liner of the hood had coolant on it, and the majority of the fluid still on the engine was from the radiator cap.

Ask the shop to first pressurize the system and check for leaks, then check for a blown head gasket by sniffing the gasses in the radiator with a exhaust gas detector. If it passes those tests, replace the thermostat, refill the system with anti-freeze and drive on…If the block or heads were aluminum, I would also re-torque the head(s) at this point, cheap insurance.

Possible failed water pump.