Hi everyone, I noticed that my recently purchased 2010 RX450H never really gets up to temperature (engine coolant). Even after 30 minutes of city driving and letting the car warm up before driving it. Unless the temperatures are above the freezing mark - the engine temps never seem to get up to the middle area of the needle..
It seems the car is constantly losing temperature and I can watch the needle falling when I stop in traffic for 30s or a minute. The temperature has just gotten below freezing (-10C or 14F) and we have not yet come anywhere near the full force of winter here in Ontario Canada
The issue is that in order to warm the vehicle and get the heating going, I have to drive with a heavy foot so the engine is constantly running which defeats the purpose of spending more and buying this hybrid.. it seems I can only get the engine temperature needle to stay up if I'm on the highway at constant speed (on a cold day).
Driving around town for 30 minutes doesn't allow the car to warm up which is odd and I doubt good for the engine itself in cold conditions? Is there anything I can do?
Car has ALWAYS been maintained at Lexus dealer since new. Nothing needs to be done from what the dealer said

 

Do you have a code reader? If so hook it up and find the real time engine temperature reading. Are you certain the engine coolant level is correct?

 

I find leaving the front defrost on helps keep the engine running and warming up faster than the regular heating setting.
It still takes a good 15-20 minutes stop/go city traffic with some hilly sections to really warm up.

 

Ok this makes sense. I find it silly that a car that is supposed to be efficient needs to be pushed in order to run efficiently in cold weather. It defeats the purpose in my opinion. Wish I had just settled for the RX350 at this point

 

Maybe the thermostat is not functioning properly. It may be opening too soon, or not closing at all.

 

I experienced this with my RX450hs in the winter as well. Although not ideal I believe it is normal.

Along with the windscreen defroster tip above, I believe shifting to “S” keeps the ice engine running at all times and keeps it running at higher RPMs which should help. I don’t have the RXh anymore so can’t say for sure.

 

I'm not sure if you are more fixated on the temp gauge or cabin heat. One thing about that temp gauge, it actually is kind of useless. I've tracked coolant temp in real time using an OBD BT module and it really doesn't particularly corelate well to the temp gauge. The lower part of the gauge can move significantly with very minor coolant temp changes, but at the middle part of the gauge coolant temps can change significantly with zero movement on the needle. I've found if the needle is above cold, well, engine is warm. Exactly where the needle is doesn't really say a whole lot about anything (especially engine/oil temp), its really no better than the "blue cold" light a lot of other cars use to indicate a cold engine. One thing you have to remember, hybrid system prioritizes engine temp, not coolant temp. If you make sure to have ECO mode OFF (very important, as ECO mode deprioritizes cabin heat!), and turn on cabin heat the system will prioritize coolant temp for no other reason than to warm the cabin (engine will tend to run more, even continuously when cabin is asking for heat), but otherwise if you find the engine stopping at a red light, then the engine is perfectly warm (the hybrid system won't have it any other way). The RXh also has an exhaust heat recovery system that channels coolant around the exhaust system to help warm up the engine faster, but once the engine is indeed at operating temp it doesn't really care what the coolant temp is (unless you are demanding cabin heat), In short, if the issue is just the temp gauge and you are getting cabin heat and the engine stops at red lights, all is good, put a sticky note over the temp gauge and be happy. Also, the "auto" mode on the climate control isn't particularly auto. My Crosstrek has an auto mode that is perfect, I leave it set at 22C and its great summer and winter, never change it. On my RXh, I have to jack the temp to at least 24C to get just a tad of cabin heat, 26to 27C is better. I have to play with temp settings quite a bit to be comfortable with varying conditions.