My car HATES when I plug in its block heater (Great White North problems at -34C [-29.2F])

Anyone else here live somewhere that gets super cold winters and whose car  hates its block heater being plugged in?

My winter sportcute (2010 Outlander V6 with 6B31 3.0) seems to have more problems when it's plugged in, even or ESPECIALLY when it's as cold as -34C (-29.2F) as it was this morning.

This has been my 2nd winter of ownership with this thing and also the 2nd year of this experiment.

What happens is that, because my coolant is already warm, my startup RPM is too low for the temperatures so the car ends up struggling or even dying. ie. 1.) Crank. 2.) Engine catches immediately. 3.) immediately settles in to low RPM. 4.) dies.

My suspicion is that because it's a car of the modern era with highly sensitive sensors, the warmed up coolant tells the ECU that " yo! I'm already warm. It's all good. You can use the 'warmed up' fuel and ignition tables " .

But noooo... the air is actually cold enough to turn hot water into instant snow. So, it ends up underfueling the extremely cold cylinders.

I think.

On the other hand, starting the car unaided after it's been outside overnight at around the same temperatures around -30C (-22F) and the engine still catches ASAP - because she's well maintained and a fairly mint example - and then settles into the high RPM cold idle (as it should).

So, yeah. It's weird and counterintuitive, but I think I'm just not ever going to plug this car ever again. It hates it so much. All the other crapbuckets I've had in the past absolutely preferred being plugged in. This one is the exception. Lol...

What it should be doing is not using the hot air/fuel tables since the Intake Air Temperature sensor is still sucking in -34C air (or something close to it). Your IAT sensor could have issues. Of course, I am assuming your car has an IAT sensor. Maybe some newer cars don't?

Interesting! I can see the car basing decisions on coolant temp and not air temp. If the coolant is warm, the cylinders must be hot, right? Reasonable assumption except for those weirdos who use block heaters.

I think you need an IAT for a MAF to work. 

That is a very odd problem. Is that thing crude enough that it still has a water heated idle speed control?  It should be all electronic by that time, but it is a Mitsu...

It was 31 below this morning, and my Volvo sure would have made less noise if I'd have plugged it in.

There are lots of problems when people cut the thermostatic cord off, and plug in above 0f.  The temp sensors disagree, and they underfuel a bunch because the ecu doesn't really know what to do.

What is the location of the block heater element, and how far away is it from the coolant temp sensor? Some Versa at work have a similar issue when it gets cold. The block heater is close to the ECT sensor and fueling gets wonky between initial start and a couple seconds later once coolant starts moving. I want to say there might have been updated ECM programming as a fix....

If this is the same issue, maybe try using either an oil pan heater or a hose mounted inline heater.

Does leaving the a/c on cause the fast idle to kick in?

What advantage is the block heater giving you?  If it all works well without being plugged in, I'd likely leave it unplugged.  Though I do know the joy of faster heat . . .

ZOO (Forum Supporter) said:

What advantage is the block heater giving you?  If it all works well without being plugged in, I'd likely leave it unplugged.  Though I do know the joy of faster heat . . .

Mostly, at 30 below, it helps not tear the innards out of your engine, and allows the oil to be thin enough that the crankshaft isn't trying to turn in syrup.

Is this a stock block heater or aftermarket?  Is it on the oil pan or in coolant?

I've always been told to heat the oil and not the coolant. but I'm not super helpful as I don't plug my cars in and they live in a garage in Minnesota.  I have had my old car at the airport parking during a polar vortex -40f air temp and she started right up.  

Maybe a seasonal reset of it's starting parameters.  Can it relearn the cold weather starting program?   No mater how confused the inputs are to start with once started it should recognize the low idle and other wonky sensors and adapt...right?

We used to use an oil heater - pull out the dipstick, put in the heater down the tube and plug it in.  Newt morning, warm oil - enough to facilitate starting. That wouldn't affect the coolant temp sensor....

Try an oil pan heater.  Warmer, thinner oil will flow more easily an produce less drag on the engine which may help the issue.  That, or you need a lower power block heater (or one with a thermostat on the engine side) so it doesn't get the thing quite so warm (and it still thinks it needs to warm up, just not from -30). 

When you turn the key on, what does the temp guage say before starting?

Could you put the heater on a timer so it only come on for a short while before you start it? Coolant would be at 30 degrees instead of 90 for example.

wspohn said:

We used to use an oil heater - pull out the dipstick, put in the heater down the tube and plug it in.  Newt morning, warm oil - enough to facilitate starting. That wouldn't affect the coolant temp sensor....

This type is very convenient to use but also the most dangerous - they can light the oil on fire if they're removed while they're still on, or removed too quickly after unplugging. It's basically a dipstick with a soldering iron built into the tip.

Is that a block heater in your pocket, or are you just glad to see me?

Hey guys!

Thanks for all the comments.  Please know that I read through all of them, I just decided not to quote each and everyone in this initial reply.

Anyway, all y'alls diagnoses, along with my initial suspicion, led me to experiment further. Acting on the idea that the coolant temp sensor was being overcooked for being far too close to the heating element, I then decided to cut off the power to the outlet about 5 minutes before heading out to start the car. This is in the hopes that some convection would have wicked away the hot spot right by the element (and presumably the coolant temp sensor, or a sensor of some sort). I may lose some heat overall, but I figured it was worth a try.

Result: The ultra low, sub 1000rpm idle that results in the engine dying isn't that low anymore. It's still on the low side, but at least I don't have to assist it with the throttle like I were coaxing an old carburated beater with worn rings.

 

Gearheadotaku (Forum Supporter) said:

When you turn the key on, what does the temp guage say before starting?

Could you put the heater on a timer so it only come on for a short while before you start it? Coolant would be at 30 degrees instead of 90 for example.

The temp does not register as anywhere near warm. It just registers as cold.
But anyway, see my previous reply: I think I can reasonably conclude that it's a placement issue with the block heater in that it's too close to the coolant temp sensor (or a sensor of some sort).  So, instead of running the block heater for a short time right before I start, I do the opposite: I switch on the outlet I'm plugged in halfway through the night when I have to go pee, and then I cut it off as I'm tying my shoes and layering up.

Given where I live these temperatures are completely nuts to me, but ... could you plug in into an outlet that has a timer on it? If you leave for work at 7 am, have it turn off at 6:30 and by then the engine will be somewhat colder but not as cold as if you had not plugged it in at all. 

I have no idea how these engine heaters work and at what temp they keep the coolant ... so maybe what I stated is pure bs, but just a thought. 

Fueled by Caffeine said:

Is this a stock block heater or aftermarket?  Is it on the oil pan or in coolant?

 

I've always been told to heat the oil and not the coolant. but I'm not super helpful as I don't plug my cars in and they live in a garage in Minnesota.  I have had my old car at the airport parking during a polar vortex -40f air temp and she started right up.  

It's a dealer installed thingie right when the car was new, but I believe it's aftermarket as opposed to a factory designed option. Something about the cord makes it look.... cheap. 

My car does start at -35C, like I said. I was just trying out methods to help it out, but it always surprises me so much how the car does not like it.  

See: my first reply after the initial post.  I think I've narrowed it down sensor placement.

Run_Away said:

What is the location of the block heater element, and how far away is it from the coolant temp sensor? Some Versa at work have a similar issue when it gets cold. The block heater is close to the ECT sensor and fueling gets wonky between initial start and a couple seconds later once coolant starts moving. I want to say there might have been updated ECM programming as a fix....

 

If this is the same issue, maybe try using either an oil pan heater or a hose mounted inline heater.

Yes!  THis, along with my initial suspicion, is what prompted me to try out giving the block heater a break before starting it.
See: My first reply after the original post. I think it's a sensor placement issue where the heating element just heats everything in its vicinity, giving the coolant temp sensor false readings - presumably because its too close to the heat source.  ONce the engine does turn over after I've helped it out a bit with the throttle and the fluids have circulated, my idle does go up.

Will look into the stick on oil pan heaters.   Maybe next year though. ;)

Slippery said:

Given where I live these temperatures are completely nuts to me, but ... could you plug in into an outlet that has a timer on it? If you leave for work at 7 am, have it turn off at 6:30 and by then the engine will be somewhat colder but not as cold as if you had not plugged it in at all. 

I have no idea how these engine heaters work and at what temp they keep the coolant ... so maybe what I stated is pure bs, but just a thought. 

Frozen north resident here, this is exactly what I used to do when I had a car with a block heater that I parked outside.