The radiator fluid in my vehicle is low. I don’t see any leak on the floor, where is it going?
What vehicle is it? ’93 Toyota 4Runner, Automatic
What engine does it have in it? ’99 5vze 3.4l V6. (That’s not original)
How many miles? The body has 160K on it, the engine has 30K since the rebuild.
Does it have the original stock radiator (all metal) or aftermarket (plastic/metal)? This has the original stock radiator, it’s all metal.
Is it overheating? No it isn’t.
Have the head gaskets ever been replaced? Yes, about 30K miles ago when the engine was rebuilt right before it was put in.
Diagnosis by phone: If this was the original 3.0l V6 I would be concerned with a head gasket leak as these were prone to leaking on cylinder 1 and 6. My guess would be that you have a very small leak somewhere in the system that is letting out enough coolant as to create a loss, but it is small enough that it doesn’t ever hit the ground. It’s either evaporating, or pooling somewhere that can’t be seen.
Final diagnosis: Pulled the radiator out and took it to a radiator repair shop. Sometimes these are hard to find as most places just sell new aftermarket radiators. I wanted to look into the price for repair vs. new because of the cost difference and because the customer wanted to stick with an all metal radiator. The radiator shop checked it over and suggested two different routes. The first one would be to solder/braze the cracked area. This would be the cheapest way, but with the amount of other suspect areas on the top tank it was suggested to just replace the whole top tank. The other suspect areas were showing signs of starting to leak also. If the current leak is repaired and then the system pressurized the other areas would start to leak due to the higher pressure. The new top tank with a cleaning (rod out) and installation was only slightly higher than the cost of 2 repairs.
Solution: Replace the top tank on the radiator. Reinstall the radiator with new fluid. No more leaks, coolant stays the right level and it’s ready for summer, 4wheelin’, and running the A/C.