So the other day temperature was in the 40s but I noticed: ICE temps up around 92-93C little heat to cabin The coolant overflow was dry so I filled to the line and let the car cool. Two hours later, I popped the cap and put only a cup or two in directly. Mostly it bubbled and didn't really take a pour. Now I drive around and the ICE runs 83-86C, much better. A lot of cabin heat too. Bob Wilson
Bob, That seems a lot of coolant to vanish in the, presumably, no more than two years since your last coolant change. Any suspicions as to where the leak is? -Chap
Today I was driving around town and the coolant temperature was still 88-93C. So I set the heater on about 80+F and no heat. Max heat did turn on the electrical elements but no coolant heat. When I got home, the radiator hoses were stiff (under pressure.) The radiator overflow tank is still half-way, to the fill mark. Right now I am thinking either bubble of air in the heater core or the electrical pump that circulates cabin coolant is not working. Any thoughts? I wonder if I need to get a tool to draw a vacuum? Bob Wilson
If the ICE is running, the belt-driven water pump should be creating the heater core flow; the electric pump only takes over when the ICE is off. Can you really tell when the electric elements come on? I've never been able to (have been tempted to add LEDs just to convince myself it really happens). -Chap
Hi Bob, I suggest that you use the Lisle yellow funnel to hold radiator coolant. The advantage of that funnel is that you can have the coolant level 2-3 inches above the radiator, thus providing more pressure to get the coolant into the system. Make the Prius READY and rev up the engine full throttle (which will probably only be 3K RPM when the gear selector is in P). Have the cabin heater turned on, MAX HEAT, fan speed on full. Rev up the engine for around 10 minutes or until the fluid level doesn't drop any more and the cabin heat is good. If you continue to find the fluid level dropping then you probably have a cylinder head gasket leak or perhaps a leak in the radiator itself or a hose. Or maybe the engine coolant pump bearing is leaking. Look for pinkish stains on the radiator, engine water pump pulley interior, and the hoses (if you are using Toyota LLC or SLLC coolant.) Check cylinder compression using Mini VCI to spin the engine at the proper speed, and a cylinder compression pressure gauge screwed into the spark plug holes, one at a time. All spark plugs should be removed during this test.
The funny thing is the funnel is cheaper than going to a shop and then I'll another use once tool.... maybe. Hummmm. Bob Wilson
