This guerrilla automobile tech tactic saved the day for me. It had worked before, and it worked again.

On a recent cross-country trip, we encountered extreme overheating out on the open road. A quick trip to the auto parts store, or a planned visit to the mechanic, were not options. Our family holiday weekend was in jeopardy. What to do?

Like a good boy, I had checked the oil and topped off the radiator the night before. So why, 45 miles later was the Beast chugging and lurching and about to sputter to a stop? I had just enough momentum to pull off the interstate and coast into the rest stop. The needle on the temperature gauge has gone off the scale, and an indicator in the instrument panel said “check gages”. There was no steam and no water leaking, but there was heat – lots of it. Though it was only May, summer was in full swing under the hood – it felt like an oven!

The radiator and the entire cooling system was dry. So where did all the coolant go?

The first step in remediation is to refill the system with liquid. But without proper diagnosis of the problem and correction, the trouble was sure to repeat itself. With family members using a half dozen water bottles to shuttle water from the rest room, it took about an hour, which gave me plenty of time to ponder the situation.

During that time, scalding hot steam greeted me every time I poured another bottle in. I have always heard that you should never add water/coolant to a hot vehicle unless the engine is running, lest the cool meet the hot and crack the engine block. That makes sense to a degree, except, I reasoned, that the temperature change in the mass of a 454 engine resulting from a bottle of water would not occur rapidly enough to damage the engine.

Well, here is how I looked at things…

Scenario

■ Complete and utter loss of coolant in 45 miles under normal driving conditions
■ No steam and no leaking of antifreeze
■ No signs of water coming out the tailpipe
■ No signs of water in the oil
■ No signs of leakage from the weep hole under the water pump
■ Radiator cap seemed tight enough
Possible root causes

■ Thermostat failure – probably most common among all possibilities, and the least expensive and the easiest to fix.
■ Water pump failure – also common, but more difficult and more expensive.
■ Leaking head gasket or cracked head or block. This would account for the coolant to disappear without a trace, by its escaping through a combustion path or into the crankcase. There would also be a high probability of impact to the engine’s performance.
There might be more, but those are the biggies that come to mind.

With the cooling system refilled, it was time to trouble-shoot in a more controlled situation. So, to start the Suburban back up; which brings me to another point. Extreme engine heat can fatigue and damage other components. In my case, the battery was shot.

So, after a jump start from another friendly traveler, using the jumper cables I always keep under the back seat (wish I’d had my tools that day also). With some extra water on board, we decided to push on down the road to the next town with a truck stop, about 45 miles away.

When we got there, she was running hot again. I opened the hood to take a look. You have probably and hopefully heard to be careful when opening the radiator cap on a hot engine. That is good advice. Here is how I do it… First, I squeeze the upper radiator hose to get a feel for the temperature and the amount of pressure. If it is absolutely too hot to touch, or feels firmer than a tennis ball, then forget it.

Satisfied that it was neither too hot nor too pressurized, I slowly and carefully turned the radiator cap to its depressurized catch. That is the point where the pressure seal is released and hot water could escape, but the cap still will not lift off. (I have heard horrible tales of people being badly burned by boiling coolant. Their flesh is so badly damaged that their skin comes off. In extreme cases, death can occur).

Next, I squeezed the upper radiator hose again to make sure there was no pressure left in the system. Then, I removed the radiator cap carefully, successfully and safely.

The water level was low again, but not empty. And the engine was nowhere near as hot. I decided that it was probably the thermostat causing the problem, and that I would try my quick fix. If I was right, it would solve my delimma, and if I was wrong, I would lose only a few minutes of my time.

The Solution:

Borrowing not more than a pair of pliers and a screwdriver, here is how I fixed the problem. With the pliers, I removed the snap ring that held the upper radiator hose to the elbow on the top of the engine that houses the thermostat.

The thermostat is a little round mechanism that acts as a doorway – a gatekeeper rather – to the liquid in the engine’s cooling system. It is designed to be closed when cold, then to open at a predesignated temperature – such as 160 degrees f, or 180, or whatever. There is a spring that keeps it closed by default. But it is made in such a way that when it gets hot enough, certain aspects of it will expand and open the gateway, thereby allowing the liquids to pass through.

If you run your vehicle without a thermostat, like I did once, it might not ever reach a suitable temperature for it to run properly. In my case, it was cold, the engine remained cold and ran poorly, and I froze inside because the heater had no heat since it needs the warmth of the engine to warm the passenger compartment.

But on the other hand, if your thermostat is stuck, then the coolant will not circulate, and the heat builds up in the engine because it cannot be dissipated through the radiator. Since our Suburban had encountered several months of inactivity, I believe that some of the resulting rust that accumulated on the thermostat has something to do with its sticking and failing me.

OK, I have told you a lot about my experience and about engine cooling and related problems to bring you to this point. So, let’s get on with the procedure already!

With the upper radiator hose off of the connector elbow, I had immediate access to the thermostat on a few inches inside below. With a screwdriver used as a spear (the bigger the better) and a hammer or something heavy, simply pound the tip and shaft of the driver through the thermostat. As long as you focus your damage on the thermostat and are careful to avoid hitting the water elbow or the manifold below the thermostat, you should be fine and need only to replace the thermostat and water elbow gasket when you get the time.

After sacrificing my thermostat and putting the hose back on and refilling with water, I was able to see the water circulating in the radiator (easiest to see when the cooling system/radiator is not completely full). I was back on the road with no more colling problems, and still am now, hundreds of miles later.

Unfortunately, the heat zapped the battery, which had to be replaced. And also the heat seems to have exacerbated some problems with the ignition system, such as with the plugs, wires, and distributor, which the dealer says all need to be replaced.

In the end, I hope this little trick can help you if you get into a pinch. But please, always remember that hot fluid from your radiator can be injurious or deadly, and that pouring water into the radiator of a hot engine can result in an unexpected volcanic-type eruption of scalding water.

With that, I wish you all the best!

Michael

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