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Normal Operating Sounds

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Re: Normal Operating Sounds

#101

Post by Roark66 »

sbierwagen wrote: post #50
jacquesm wrote: post #16

Earlier quoted context omitted.

A gasoline based ICE is so incredibly inefficient it needs to shed heat or it would melt down. It makes more heat than that it makes motive power (the thing it is designed to do...). A 50 KW engine makes 200 KW(!!) of heat (at full throttle). Most of that heat energy exits the system through the exhaust gases but there is plenty that gets stuck in the body of the engine and you need to remove it from there somehow be…

>Some diesels got so efficient though that they needed an extra in-line heater to have enough heat for the cabin in specific operating domains I live on the top of a hill, so the first seven minutes or so of me driving anywhere is coasting at minimum engine power. Once air temp gets below 10C it's a long, slow painful wait for the vents to start blowing warm air. Especially unfortunate when you're waiting for the def…

Maybe check if your EGR is operating properly? Also the resistance heater if equipped.

Most diesel cars equipped with EGR also detect its (frequent in older cars) failures, but I suppose it's possible to have a fault without it being detected.

EGR is responsible for recirculating exhaust gases back into the intake primarily to increase efficiency, but a nice side effect is that it heats up the engine a lot quicker.

Also, many diesel cars sold around here since 2000 or so are equipped with a resistance heater that kicks in when the engine is cold. Perhaps that's different in other markets.

Re: Normal Operating Sounds

#102

Post by londons_explore »

dosshell wrote: post #92
dralley wrote: post #28

Earlier quoted context omitted.

My understanding is that high-end residential heat pumps (e.g. Mitsubishi HyperHeat) will do this at lower temperatures as well. If the temp drops into the zone where the heat pump starts losing effectiveness (which on such systems is still pretty low, supposedly mine provides the full heat rating down to around 0F), they can run the blower motor in a less efficient regime to supplement the heat pump with a bit of re…

Interesting, that does not sound efficient? How much more efficient than using electrical heating directly instead? 0F ? That can't be right? My Mitsubishi gives heat to around -31F (MSZ-RW Sumo)

The efficiency of electrical resistance heating is exactly the same whether you use motor coil resistance or resistance wire.

However, they simplify their system design a little (fewer contactors, fewer wires, fewer components to buy/test)

Re: Normal Operating Sounds

#103

Post by londons_explore »

JasonSage wrote: post #82
sgc wrote: post #69

Earlier quoted context omitted.

Car engines heat up when you park, because the air cooling and circulation of the coolant keeps it cooler while driving. It seems completely within the common laws of physics that when you are at not so uncommon temperatures, the coolant closer to the engine heats up well above standard operating temperatures once the car is off, and then convection currents bring enough of this overheated coolant to the sensor to tr…

This is 100% correct. For those curious, the coolant around the engine block can boil and flow upwards after the engine is off, and the coolant circulation system is designed to handle this pattern. You can observe this yourself if you overfill your coolant and take it out on a hot day, the excess hot coolant will bubble up and run out for a good while after the engine is off. I second the advice that if the engine i…

It's also a common cause of breakdowns... The fan normally cools the radiator, but the temperature sensor is on a coolant hose. Since the engine is stopped coolant isn't flowing so the fan isn't cooling the same thing the sensor is sensing, which means it can end up running for 30 mins or more. Since the fan can be 20 amps or so, you can easily kill old car batteries due to this effect. User comes back after an hour shopping to find their car battery is dead.

If I was a car manufacturer, I would wire the fan into the ignition circuit so it can never run with the ignition off - it's fairly useless to have a fan blowing on a radiator when the coolant isn't flowing anyway.

Re: Normal Operating Sounds

#104

Post by userbinator »

bhasi wrote: post #61

"Creaking From the Tires or Brakes" I don't have a Tesla, but I hear this sound in my own car, especially now that it's winter. I began hearing this after my recent car service that involved a ~real~ rear brakes replacement. When I took my car to the service guy, it was afternoon and I was no longer able to reproduce the noise. This was driving me crazy until now! I now know it's nothing to worry about.

If it was a Tesla, you might want to check that brake pads are present: https://news.ycombinator.com/item?id=29949728

Re: Normal Operating Sounds

#105

Post by smt88 »

kccqzy wrote: post #36
smt88 wrote: post #33

Earlier quoted context omitted.

Is this universal? I've driven the Rav4 Prime and Ioniq 5 extensively and neither made weird sounds.

I've driven the Ioniq 5 and I can easily hear a high pitched motor whine at speeds between 45 and 60 mph. I cannot hear any noise below 45 or above 60, other than the intentional pedestrian warning sound. I suspect as I age my ability to hear such high pitched whine will be gone.

Motor whine isn't a weird sound and it's unsurprising Hyundai doesn't have an FAQ page to explain it.

I suspect many of these noises are due to Tesla's notoriously poor build quality.

Re: Normal Operating Sounds

#109

Post by gregoriol »

synaesthesisx wrote: post #30

It's astounding just how quiet EV's are; they can make you hyperaware of other noises (hence why this page exists).

It's more a tech-guy thing than EVs: I'm very aware and listening to sounds made by ICE cars or motorbikes, and I'm not a mechanic, just a little bit techy. The sounds are different on EVs because some are new to us: those related to charging, the battery, the motors, ... we don't expect them yet. That doc is really good for this, but only for us technies. Most people won't care until something is not functioning though.

Re: Normal Operating Sounds

#110

Post by gregoriol »

smt88 wrote: post #33
synaesthesisx wrote: post #30

It's astounding just how quiet EV's are; they can make you hyperaware of other noises (hence why this page exists).

Is this universal? I've driven the Rav4 Prime and Ioniq 5 extensively and neither made weird sounds.

It would highly depend on the brand and model: one would expect Rolls-Royce EVs or even some like Lexus not to make any annoying noises.
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