2013 Prius V overheating, using coolant

Wolfgang Langlois · May 15, 2026 at 11:06 PM

The overheating warning sign coming on often, coolant container used up, some splashing around container,
no signs of other leaks

Brian1954 · May 16, 2026 at 9:19 AM

How many miles?

There is a very good possibility that the engine water pump is bad. To confirm, you need a scanner that can read the engine coolant temperature and water pump speed.

Mendel Leisk · May 16, 2026 at 10:55 AM

Any unusual engine shake/noise during cold-starts?

rjparker · May 16, 2026 at 12:26 PM

No observable leaks could mean the cooling system is not moving coolant or is clogged up with stop leak and is causing the reservoir cap to release.

OR

The head gasket is blown causing coolant to be burned. Symptoms include occasional severe rattling at engine startups (actual engine start not just Ready). If severe rattling happens and then clears it is almost always a head gasket. Eventually loss of coolant causes overheating and reservoir releases.

Testing

Filling the system is essential before testing.

Some codes may be present and can help determine the scenario. Head gasket problems may not code for weeks or months.

Monitoring both coolant temps with a scanner like Techstream or an app like Car Scanner can help diagnose the first scenario.

Running a borescope test is good for the second scenario. This should be done with the engine cold and the cooling system manually pressurized.

After warmup water flow can be seen here

If the coolant overheats, this pressure cap releases coolant

Techstream scanner with both Coolant Temps, one in Combination Meter ecu

Car Scanner App and bluetooth adapter

Two coolant temps on engine