Anyone have issues with their RDX starting in about -28ish degree Celcius weather? The car would crank, and sound like it wants to start, but just dies. It took roughly 5 attempts before it actually started.
Anyone know if there is a fail safe built in where it won't start if it's too cold or alike?

 

I dont think there is fail safe by low temperature.
maybe you should get block heater and use better oil with lower pour points, like Mobil1 0w-20 EP (-54C)

 

I second the block heater
some regions with extreme temps like that seem to be the norm

 

If it cranks it’s pretty clear there’s no “fail safe” - it’s just too cold. I grew up in Alaska and we always had a block heater that we would use if it was substantially below freezing. Most folks on the web suggest it’s a good idea at temps of 5-10 degrees F (-12 to -15 C) or lower.

 

Could also be a fuel problem, perhaps water (ice) in the fuel line. Regardless, at -28°C (-18°F), 0-weight oil is around 200 centistokes or more (depending on the blend). At normal operating temps (212°F), 0W-20 oil is around 7cSt.

 

some have very low pouring point, especially with high PAO concentration. Mobil1 0w-20 EP is 60-70% PAO and it has one of the lowest pouring points, unless you go with boutique oils like Amsoil/RedLine

 

Very true. The Pour Point is pretty much defined as the temperature in which oil becomes a solid plastic. With the ATSM D97 test, a lab fills a beaker with oil and holds it horizontally, so the oil will pour out of that beaker. Then the lab lowers the temperature until the oil no longer moves. I’m pretty sure it is a 5 second test. Meaning the lab person holds the beaker horizontally for 5 seconds and if the oil does not move out of the beaker, that defines it’s pour-point temperature. In centistokes, that is normally over 30,000 cSt.

If an oil has a pour point of -65°C, that means it can still move under the force of gravity. At -68°C, it is a solid. But what does that imply at -30°C? The oil obviously flows, but like what? Honey (2,000 cSt to 3,000 cSt)? Molasses (5,000 cSt to 10,000 cSt)? That will still take a long time to reach the top of the engine. To me, the pour point is a nearly meaningless number. Sure, a top quality oil with a -65°C pour point will flow better than a “lesser” oil with a pour point of -50°C. But at -35°C, if one is like Honey and the other like Molasses, both are still too thick and may cause oil starvation problems. In my opinion, knowing an oil "still pours" at a very cold temperature should not give a person a sense of “oil safety.” A block heater would be very wise at those temperatures.

 

Agree with others here. If those temps are the "norm" during the winter, I would strongly consider an engine block heater - 08T44-TJB-200 for about $75.00

 

Block heater is ideal, but nice to get good oil that flows as much as possible at low temps

 

Agreed - especially if OP lives in an apt complex or doesn't have easy access to an electrical outlet.

 

Thanks for the input all, I do have a block heater and live in colder climate part of Canada.
Although I do understand that block heaters help in these situations and are recommended, they are certainly not a 100% must. The oil in the car is whatever the Acura dealership put in, which I assume would be 0W20 (though no way to confirm)

What is a surprise to me is that my 2009 Honda Civic Si had no issues starting in these temperatures without a block heater. I understand not healthy for the motor/battery etc, but it still did it! The RDX cranked and sounded like it wanted to start, but just died off. I was told by the dealership that it is normal behaviour for it to auto-shut off in these extreme temperatures. Maybe I will drain the oil and refill it myself to confirm next oil change...

 

Different 0w-20 oils will flow different at -28. Cheaper oils not great at low temp flow.
Dealership said there is a shutoff at -28?? Thats crazy, I hope they are wrong

 

Different car with different electrical programming, mechanicals, oil, etc... will behave differently. I get what you are saying but not necessarily a good comparison. I wouldn't bank too much on being told by the dealership that it is normal behavior. That answer will likely satisfy most owners and not question it, but here on an enthusiast board - you have and will get folks calling .

 

We've seen sustained temperatures below -25C for the last few weeks with several mornings as cold as -35C. I don't use a block heater either but this is pure laziness. There can be no argument about the benefits at these temps.
Below -30C mine will crank over and start four times out of five. On the fifth attempt it starts quickly but dies after a second or two. Another tap of the button and away it goes.

I have noticed a few other peculiarities at cold temps.
Just recently my front seat auto back and forth ingress function has stopped working. It stays at the rearward position during startup and departure. All that is required to restore the function is to shut off and then restart the engine. This works even if the engine is not yet warmed up.

Rear defroster has gotten quite weak. I noticed this last winter. No noticeable broken wires but it heats at less than half the intensity it did when it was new.

I've managed to get stuck a couple times. Nothing serious but it took a little rocking to get things free. The engine will actually stall during this activity if you really start applying power. I think the engine needs a little more idle speed or idle air control solenoid preset.

 

Your Temps are similar to what I've been experiencing the past 2 weeks. Do you park your car outside or inside? Your startup success rate is higher than mine at these Temps.

 

Have either of you considered 0W-16 oil?

 

Mine stays outside.
I have not heard of 0W-16 oil.

 

I am using Mobil1 0W-16 right now. Scotty Kilmer had a YouTube video where a Honda CRV owner with 1.5L engine and experience with oil dilution and after switching to 0W-16 the dilution went away. I am giving this a try. Oil economy went down 2-3 MPGs which is a surprise to me. I take very short trips 1-2 miles each way and the thinner oil seems to help warm up the engine quicker. I might switch back 0W-20 Pennzoil Ultra Platinum Full Synthetic at the next oil change.

 

Yeah. OW-16 oil’s been around for a while in Japan. Recently Toyota and Honda made it their recommended oil in the USA. The primary goal of being even thinner than 0W-20 oil is to reduce internal engine friction (oil pump mainly) by a minuscule amount to eke out a tiny bit better fuel economy. Most major oil manufacturers offer it (Mobil 1, Amsoil, Pennzoil, LuquiMoly, Castrol, Honda, Toyota, etc.). Mobil 1 one specifically promotes it to optimize fuel economy, heat faster, and to provide better cold start protection. Here is a quick comparison of Mobil 1 0W-20 and Mobil 1 0W-16.

· 0W-16

· Viscosity at 100°C (212°F) = 7.1 cSt

· Pour Point = -54°C (-65.2°F)



· 0W-20

· Viscosity at 100°C (212°F) = 8.6 cSt

· Pour Point = -54°C (-65.2°F)



I’m sure you just noticed that at 212°F, 0W-16 is 7.1 cSt versus 8.6 cSt for 0W-20. That is pretty significant. HOWEVER, both have the same -65.2°F pour point. You’d think a 0W-16 blend would have a lower pour point (in general, be thinner at very cold temps) than a 0W-20 blend, but the numbers don’t confirm it. Yet, it is marketed as a "cold temperature" oil and common sense says it should flow better in deep sub-zero temps.

Anyway, your call. In winter, yours especially, I’d have no problem using 0W-16 it in my car. In summer, with a hot running turbo engine, absolutely no way. Here's an article on the subject if this interests you. If you scroll to the bottom, you will see a link to Mobil 1’s 0W-20 spec sheet.

https://practicalmechanic.com/2021/0...ere-to-get-it/

 

Mobil1 EP is probably the best choice for low pour temp if you dont want to pay crazy prices.

RedLine 0w-20 is -60C, and viscosity at 100C is 9.1 cST. Too bad its not API licensed (for those that care). It will cost double of M1...