A young man calls to tell me that his car is overheating. I inspect and quickly find that the fluid I added is pouring out of the radiator on the drivers side. This seems to be a pretty straight forward repair. I provide a price estimate and quickly receive an approval. We agree to perform the repair the following evening. The next day turns out to have intermittent heavy rains. Being that we are a mobile service provider, it can make the work challenging. Fortunately, the rain lifts and I am able to get to work on the vehicle. the young man is anxious to get going again, so he is ever present. The repair goes relatively well, and after I remove the radiator, I point out the area of the radiator that is leaking, due to the large missing section. The owner states that he doesn't remember hitting anything. I reply that sometimes debris in the road can cause damage. The radiator also looks pretty rusty, so we leave it at that. I finish the installation of the new radiator and top off the fluid. By now it's getting dark, and the young man keeps getting phone notifications that lead him to keep asking, "How much longer?". The vehicle appears to be running fine in the driveway and there is no sign of leaks or overheating. So, I clean up, put away the tools and announce the job complete. All seems well.
The next day, I am contacted by the young man and he states that the car ran well the evening after the repair, and most of the next day, but then it started overheating again. I state that sometimes trapped air in the cooling system can lead to this issue, and I would arrange to take a look. I get to the vehicle and open the radiator. I add a little fluid and start the engine. For about 25 minutes, I run the engine and make sure that the fluid level is up to proper level. During this time I do my due diligence and watch the temp gauge in the car, monitor heat vent temps and observe the cooling fans functioning. Everything seems to be working great. I reinstall the radiator cap and test drive the vehicle. The engine temp stays in range, but the temperature from the dash vents go from warm to cool. I return and remove the radiator cap again and check fluid level. It seems fine. I check temp from dash, it's hot. I reinstall the cap and test drive. Cool air from the vents again. I advise the customer that I am going to get a new radiator cap to install. I begin to suspect a pressure issue with the system.
The next day, I pick up a new radiator cap, and I get a call from the anxious young man that he drive his vehicle a couple cities over, and it overheated. I reminded him that I had wanted to replace the cap and had assumed he would not be driving extended distances until I had received it and installed it. My mistake. He picked up the cap from me and stated that he could handle installing it. I had a couple other appointments, so I agreed. For almost a day and a half, all seemed well. Then it struck again. Car overheated. I asked about how the car ran, vent temps and other observations. He stated that everything seemed perfect right up until it just suddenly overheated. I told him that I would go look into it. I sat thinking about the conditions, and started to get a feeling that we might be dealing with a small head gasket leak causing big problems. I inspected the vehicle again, then turned it over to a shop that could perform the tests for this issue, as well as the repair. They confirmed my concern. Head gasket had failed. I contacted the customer and told them the news. There wasn't much to do but approve the repair. What else could they do? I explained that the high pressure in the cooling system would most likely have caused the radiator blow out. Since it isn't common, the most sensible thing to do was just replace it. Everything seemed to be fine. I had no reason to suspect head gasket in association with a radiator failure. Either way, both repairs would be required. The customer understood.