With the upcoming winter storm about to make its presence known on the East Coast (along with a full week of below-freezing temperatures) I thought it would be prudent to block my Gen 5's radiator to reduce warm-up time. So far, it appears to be working well as I was able to get the ICE up to 150°F with moderate driving in less than 10 minutes with an ambient temperature of 15°F. I've attached pictures of my setup. Thanks to USPS for providing their free Priority Mail flat rate boxes!
It appears to have them in general based on what I've seen in the repair manual, but I can't determine whether my Prime SE has them or whether it was/is part of some "cold weather" package/option.
It is part of a cold weather package, so not present in all Japanese market cars, but it's part of the standard 'cold weather package' fitted to all American and European ones. Still, it's not going to be as effective as a block like this.
You should be cautious, how much you block, and what zones. It'd be best to leave the inverter coolant zone unblocked.
Good point. I've heard that about half of the radiator is used to cool the ICE and the other half is for the inverter. I found mention of that in this thread about the Gen 2: Hell -Red Triangle after coolant inverter replacement | PriusChat Is this still true for the Gen 5, though?
You can look at the coolant drain valves to get a general idea. Like to point out that your putting cardboard over the condenser, so your heat pump won't be working efficiently, also your traction pack cooling system won't be able to remove as much heat. Traction pack is freon cooled in a gen5 Prime. It's your thermostat that controls coolant flow through your radiator and truckers only block a portion of their radiator, because they need the additional cooling during the summer months - so they run with an oversized ICE cooling system..... It's your car, do whatever you want...... YMMV
Inverter coolant is likely cooled through an integrated portion of the radiator. Where it is for gen 5 should be determined. Gen 2 was at bottom, gen 3 at top, gen 4 I forget, and so far I'm not sure about 5th gen. Looked a bit, but no luck. A pic of gen 5 radiator shows extra spigots near bottom, so maybe there. The "New Car Features" @ChapmanF often mentions may have info. I've not seen that, and it doesn't seem to be "floating around", so maybe it'd take a subscription, just to find out if that document has anything.
To the best of my recollections, I traced out the transmission ATF lines when I did an early replacement of my gen4 ATF. The gen4 ATF cooling is located in the lower third of the radiator. If the above picture is an accurate depiction of a gen5 radiator, those ATF lines still look to be in the lower radiator portion.
Inverter coolant temperature can be monitored via CarScanner with the Prime profile and displayed via CarPlay. I think a similar Android app can as well, as has been noted. Still think you're rolling the dice though, esp with auto shutters. I tried it with the efficient little TDI diesel on a VW. Too much futzing around, and this thing is way more complicated.
Yeah, the PHEV really wants air through the radiator to use the heat pump to heat the cabin, at least down to -10°C. You can surely hear that fan going nuts if near that temperature.
Thanks all for the advice. I searched through the available PIDs/metrics for my Prime in both Car Scanner and OBD Fusion but can't seem to find the value for inverter coolant temperature. ICE coolant temperature was easy to locate, though. Has anyone had luck finding the inverter coolant temperature in either app?
Nice work. I think? But a question: doesn't the car logic not open the radiator valves at all (i.e., coolant is flowing around the engine, but not through the radiator) until the ICE is warmed up? Because, when those valves do actually open, doesn't the ICE actually need the cooling by that point?
I agree - if this is serving a purpose, it should be due to reducing overall airflow through the engine bay, not specifically the radiator. Aiming to block the grille would likely be more effective.
