I have a 2011 RDX with Turbo, and I notice that after driving an hour or more (engine at full temp), the temp gauge shows the temp at well below 1/2 way.

Using an OBD2 interface I read the engine (1) temp at 91 degrees max (at highway speeds) - and never goes above this?

What is the correct engine temp for this vehicle? On a GM I would just replace the thermostat, but not sure how to fix on an Acura (or is this even a problem)?

 

If that is celsius then 91-105 i believe is normal for most engines. Its been cold in ontario over the past few days so an immediate measurment while driving would likely produce that result. Thermostats normally open around that temperature so it could make sense as you are shoving a ton of air over the radiator to cool the coolant. Check your fuel trims, what are they at? Also dm'd you a message so that may help for many of these questions.

 

Thanks for the DM! I'll check fuel trims.

In the GM world the engine should stay at thermostat tempt even in cold weather...but I'm used to much larger engines. May low end of range is ok.

 

Interestingly enough, a quick search showed a thermostat activation temperature of 80C according to autozone. I would say Hondas run a bit colder than other engines as my volvos ran at 88C - 92C. This engine is probably at temp in that case.

 

I think the acura thermostat (for this vehicle) is 19301-RTA-003, which according to a couple of websites is 78'C. So is it normal for it to be in the 78-92'C range (or 78-105'C range as listed above). Maybe I'm just not used to wide swings in engine temperature (as I said GM engines to to run very close to thermostat temp regardless of load/external temp)

 

According to the Acura manual the thermostat starts to open at 76-80C and should be fully open at 90C.

 

The temp gauge in the RDX is a bit of a "dummy" gauge, and not at all linear from bar to bar. As long as you are within the normal operating temp of the engine (something like a 40-50 degree Fahrenheit range - I forget the exact number), it will show 7 bars which is a little below the halfway mark from left to right. If you start to get warm, say climbing a long hill with a heavy load, it may move up a bar or two, but should drop down fairly quickly once you're back to cruising. If you see it above 7 bars for any significant amount of time under normal driving, you might get it checked out.

 

You'd be surprised how much it really does fluctuate. My previous car was a Cobalt, which had an actual temp readout for coolant vs a gauge, and it was all over the place, ranging 185-200F under normal city driving and even spiking to 215+ when I got on the beans (I miss that little car). I think most cars with gauges (RDX included) are programmed to hold the same position over a certain temperature range, so that as long as the car is within the normal range you can easily glance and not have to guess whether or not it should be considered high or not.