Thermostat Issue?
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Thermostat Issue?
It seems my RDX takes an inordinate amount of time to reach normal operating temp as shown on the temp gauge. I first noticed this when I did the last software update. After 20 minutes idling it still did not reach the halfway mark at all. I sort of forgot about it until today when I was waiting to have my car washed after a few block trip to the car wash and then idling again. Anyone else having this issue? I hate to make an hour trip to the dealership for another, “It’s a normal condition.”, from the service writer. Start up temp today was 58°.
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Drifting
Joined: May 2018
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From: Santa Fe, NM
It seems my RDX takes an inordinate amount of time to reach normal operating temp as shown on the temp gauge. I first noticed this when I did the last software update. After 20 minutes idling it still did not reach the halfway mark at all. I sort of forgot about it until today when I was waiting to have my car washed after a few block trip to the car wash and then idling again. Anyone else having this issue? I hate to make an hour trip to the dealership for another, “It’s a normal condition.”, from the service writer. Start up temp today was 58°.
I doubt the analog thermostat changed with the last software update.
Last edited by Wander; Mar 6, 2019 at 10:50 PM.
Racer
Joined: Mar 2017
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Sounds like the same problem the CR-Vs are having or this is a major coincidence. Seems like its becoming more and more clear that the RDX has the same issue as the CR-V.
Oil Dilution in Honda's 1.5L Engine - Honda Problems
Honda will attempt to fix the oil dilution problem with a service campaign that includes:
Honda will attempt to fix the oil dilution problem with a service campaign that includes:
- Software updates to the transmission control module and electronic fuel injection system.
- Replacing a drain plug washer
- Replacing the climate control unit (in some cases)
- A fresh oil change
Drifting
Joined: May 2018
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From: Santa Fe, NM
I believe this is confusing cause and effect.
Replacing the climate control unit is part of an effort to allow the 1.5T engine to get up to operating temperature more rapidly in cold conditions ( presumably by keeping the control valve for the cabin heating circuit closed until the engine coolant has warmed up ). According to Honda, a small amount of gasoline gets by the piston rings under normal operation, but it is slowly boiled out of the engine oil sump once it warms up. Allowing the engine to warm up faster shifts the balance away from accumulating gas in the oil.
I suppose it's possible a stealth climate control unit firmware update was included in the D.1.1.2 infotainment system update, but I doubt it. And I'm pretty darn sure transmission control unit and fuel injection system ( ECM ) firmware isn't included in OTA updates.
As for not heating up rapidly during idling, that's pretty much by design. It's hard to be efficient and wasteful at the same time. Heat = energy.
But maybe we should replace the drain plug washer, just in case?
Who the heck writes this stuff, anyway? ( Honda techs are supposed to replace the drain plug washer anytime they do an engine oil change ).
Replacing the climate control unit is part of an effort to allow the 1.5T engine to get up to operating temperature more rapidly in cold conditions ( presumably by keeping the control valve for the cabin heating circuit closed until the engine coolant has warmed up ). According to Honda, a small amount of gasoline gets by the piston rings under normal operation, but it is slowly boiled out of the engine oil sump once it warms up. Allowing the engine to warm up faster shifts the balance away from accumulating gas in the oil.
I suppose it's possible a stealth climate control unit firmware update was included in the D.1.1.2 infotainment system update, but I doubt it. And I'm pretty darn sure transmission control unit and fuel injection system ( ECM ) firmware isn't included in OTA updates.
As for not heating up rapidly during idling, that's pretty much by design. It's hard to be efficient and wasteful at the same time. Heat = energy.
But maybe we should replace the drain plug washer, just in case?
Who the heck writes this stuff, anyway? ( Honda techs are supposed to replace the drain plug washer anytime they do an engine oil change ).
Last edited by Wander; Mar 6, 2019 at 11:49 PM.
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I have noticed some weirdness as well. But I haven't decided if the fault lies with the analog engine coolant "thermostat" ( a rubber and metal diaphragm attached to a spring ), the temperature sensor, or the myriad computers in this rolling mainframe, which may be sending bad data to the digital temp gauge on the dashboard. ( And perhaps to the climate control system, as well ).
I doubt the analog thermostat changed with the last software update.
I doubt the analog thermostat changed with the last software update.
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Burning Brakes
Joined: Oct 2018
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From: Minnesota
My reference to the software update was the 20 minutes I spent in the RDX and happened to notice the temp gauge. The update had nothing to do with the temp gauge and thermostat, or at least I’m not aware of such. It’s just that after 10 minutes the gauge (white curved line) was only showing about a 25% rise. I know modern cars are supposed to reach normal operating temp ASAP due to emissions, etc. Several things could be wrong to cause slow warm up. I’m just old and know the thermostat is usually what techs look at first, or at least they did before digital gauges, when there was no heat from the heater and/or the gauge was screwy. Of course, grabbing the upper radiator hose was the definitive check back in the day.
edit***
it was 58 degrees where the car was stored?
Last edited by Dereileak; Mar 7, 2019 at 12:16 PM.
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