No heat issue

coffeeslugg · 10-22-2018, 05:51 PM

When cold outside i.e. less than 40 degrees F the car is unable to produce hot air. The climate control is set to 84, center dial is set to red, vehicle does not overheat, coolant was flushed 10,000 miles ago by Bmw dealer.

I used to get heat in the car within 2-3 minutes even when the engine oil temperature was at 160 (far left), however this doesn't happen anymore.

I wonder if I have a partially stuck open thermostat? If the car is driven later in the afternoon the car is able to produce hot air and this issue doesn't occur.

Any ideas?

Billfitz · 10-22-2018, 08:46 PM

99% likely it's the thermostat. Suggest you list what you actually drive, it's a lot easier for those who have the same model and engine to give you the benefit of their experiences if they know what you have.

coffeeslugg · 10-22-2018, 08:53 PM

Quote:

Originally Posted by Billfitz

99% likely it's the thermostat. Suggest you list what you actually drive, it's a lot easier for those who have the same model and engine to give you the benefit of their experiences if they know what you have.

Whoops sorry about that.

2014 335i-m sport auto with 65,000 miles.

TheBingoBalls · 10-22-2018, 09:00 PM

With the car "warmed up", when you gas it on idle, do you get any heat? When my thermostat failed, it would not give heat unless I stepped on the accelerator.

Billfitz · 10-22-2018, 09:28 PM

Quote:

Originally Posted by coffeeslugg

2014 335i-m sport auto with 65,000 miles.

That makes it 99.9% likely it's the thermostat, there being an abundance of posts and videos here and there about how to replace it.

coffeeslugg · 10-23-2018, 04:55 AM

Quote:

Originally Posted by TheBingoBalls

With the car "warmed up", when you gas it on idle, do you get any heat? When my thermostat failed, it would not give heat unless I stepped on the accelerator.

No it doesn' make a difference.

vooonoo · 10-23-2018, 06:28 AM

If there's no heat at all it could be your blend door motor/actuator

Billfitz · 10-23-2018, 07:27 AM

That's a possibility, but not likely. A search of that problem shows that when it happens it's usually with only one of the vents, not all of them. Besides, the OP said that he gets heat later in the afternoon, when the outside air is warmer, and I suspect the sun shining on the car all day has had an effect as well, in essence pre-warming the engine and coolant.

coffeeslugg · 10-23-2018, 08:02 AM

Quote:

Originally Posted by vooonoo

If there's no heat at all it could be your blend door motor/actuator

I do get some heat but its extremely lukewarm.

Thanks for the help guys!

dan of montana · 10-23-2018, 10:32 AM

Agreed, 99% its the thermostat.

coffeeslugg · 10-23-2018, 05:56 PM

Quote:

Originally Posted by dan of montana

Agreed, 99% its the thermostat.

Do you guys happen to know if the thermostat would throw a check engine light?

Also I called some local shops around Charlotte NC and it appears to cost btw 600-700 bucks. Does that sound right?

Niart906 · 10-23-2018, 06:36 PM

Looks like the thermostat is about $130, then add coolant and labor and that figure sounds pretty close. Maybe a bit high.

Does your car actually get to operating temperature? Or does it run cold/fluctuate a lot?

https://www.ecstuning.com/b-genuine-...t/11537598865/

coffeeslugg · 10-23-2018, 06:43 PM

Quote:

Originally Posted by Niart906

Looks like the thermostat is about $130, then add coolant and labor and that figure sounds pretty close. Maybe a bit high.

Does your car actually get to operating temperature? Or does it run cold/fluctuate a lot?

https://www.ecstuning.com/b-genuine-...t/11537598865/

The car does get to operating temperature and doesn't fluctuate but it takes forever. I can drive on the highway for 1 hour and the car still blows out slightly warm air.

I haven't found a solid DIY for the f30 335i if you guys have any suggestions let me know.

Billfitz · 10-23-2018, 09:39 PM

It will eventually get to operating temperature, or close to it, depending on the outdoor temperature. Catch-22 is the the colder it is and thus the faster you want to get heat the slower it is to warm, if it does at all. There are youtube videos how to change a thermostat. OEM will be really expensive, I'd go aftermarket. Even then figure about $100, as it's electrically controlled, and is nothing at all like $15 spring operated thermostats.

Niart906 · 10-23-2018, 10:32 PM

Quote:

Originally Posted by coffeeslugg

The car does get to operating temperature and doesn't fluctuate but it takes forever. I can drive on the highway for 1 hour and the car still blows out slightly warm air.

I haven't found a solid DIY for the f30 335i if you guys have any suggestions let me know.

This sounds 100% like a stuck open thermostat.

DIY Here:

Also looks like Borg Warner is the OEM supplier to BMW. FCP has it for $73 vs $130 for OE BMW...
https://www.fcpeuro.com/products/bmw...ly-11537601158

bimmer456 · 10-24-2018, 05:29 AM

The engine doesn't need to be at operating temp for the heat to work as the heater uses a separate heater element and does not require coolant to be warm to work.

coffeeslugg · 10-24-2018, 06:07 AM

Quote:

Originally Posted by bimmer456

The engine doesn't need to be at operating temp for the heat to work as the heater uses a separate heater element and does not require coolant to be warm to work.

That is what I thought however I don't get any heat from the separate heater element. Does the thermostat control the separate heating element?

Billfitz · 10-24-2018, 07:48 AM

Quote:

Originally Posted by bimmer456

The engine doesn't need to be at operating temp for the heat to work as the heater uses a separate heater element and does not require coolant to be warm to work.

Some models have electrically assisted heating, primarily diesels, as it takes them longer to warm the coolant. The parts listing for a 328d shows it, that for a 335i does not. The listed part #64119230594 shows up in many diesel models, but no gas models.

bimmer456 · 10-24-2018, 08:33 AM

Quote:

Originally Posted by Billfitz

Quote:

Originally Posted by bimmer456

The engine doesn't need to be at operating temp for the heat to work as the heater uses a separate heater element and does not require coolant to be warm to work.

Some models have electrically assisted heating, primarily diesels, as it takes them longer to warm the coolant. The parts listing for a 328d shows it, that for a 335i does not. The listed part #64119230594 shows up in many diesel models, but no gas models.

Must be different for the 340 in the US as I have instant heat even before the coolant temp is up and others on this forum have reported they have electric heat with no humidity like you normally have fogging up the windows so you have to turn on the AC as well.

Billfitz · 10-24-2018, 09:26 AM

The 340i parts list doesn't show electric heat assist, the LCI 328D does. My heat comes up a lot faster than my oil temperature too, usually within five minutes at 30F. The system probably allows flow of coolant through the heater core before it allows it through the radiator, for faster heating of the car interior, but I haven't come across anything definitive on that point.

coffeeslugg · 10-24-2018, 09:43 AM

Quote:

Originally Posted by bimmer456

Must be different for the 340 in the US as I have instant heat even before the coolant temp is up and others on this forum have reported they have electric heat with no humidity like you normally have fogging up the windows so you have to turn on the AC as well.

I used to have instant heat within 2 minutes or so however not anymore.

Billfitz · 10-24-2018, 11:33 AM

This is one instance where having the coolant temperature read out, rather than oil temperature, would be helpful.

10-22-2018, 05:51 PM	#1
coffeeslugg New Member 6 Rep 26 Posts Drives: Cta9gsr --> F30 335i Join Date: Oct 2014 Location: Charlotte, NC iTrader: (0)	No heat issue When cold outside i.e. less than 40 degrees F the car is unable to produce hot air. The climate control is set to 84, center dial is set to red, vehicle does not overheat, coolant was flushed 10,000 miles ago by Bmw dealer. I used to get heat in the car within 2-3 minutes even when the engine oil temperature was at 160 (far left), however this doesn't happen anymore. I wonder if I have a partially stuck open thermostat? If the car is driven later in the afternoon the car is able to produce hot air and this issue doesn't occur. Any ideas?
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10-22-2018, 08:46 PM	#2
Billfitz General 9803 Rep 18,331 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	99% likely it's the thermostat. Suggest you list what you actually drive, it's a lot easier for those who have the same model and engine to give you the benefit of their experiences if they know what you have.
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10-22-2018, 09:00 PM	#4
TheBingoBalls Brigadier General 4740 Rep 4,981 Posts Drives: BMW Join Date: Mar 2011 Location: Toronto, Ontario iTrader: (1) Garage List 2018 F36 BMW 440i x ... [0.00]	With the car "warmed up", when you gas it on idle, do you get any heat? When my thermostat failed, it would not give heat unless I stepped on the accelerator.
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10-23-2018, 06:28 AM	#7
vooonoo ¯\_(ツ)_/¯ 537 Rep 1,000 Posts Drives: f30 328 Join Date: Nov 2017 Location: nj iTrader: (0) Garage List 2014 f30 328i [0.00]	If there's no heat at all it could be your blend door motor/actuator
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10-23-2018, 07:27 AM	#8
Billfitz General 9803 Rep 18,331 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	That's a possibility, but not likely. A search of that problem shows that when it happens it's usually with only one of the vents, not all of them. Besides, the OP said that he gets heat later in the afternoon, when the outside air is warmer, and I suspect the sun shining on the car all day has had an effect as well, in essence pre-warming the engine and coolant.
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10-23-2018, 10:32 AM	#10
dan of montana Private First Class 73 Rep 109 Posts Drives: F31 328i xDrive Wagon Join Date: May 2018 Location: USA iTrader: (0)	Agreed, 99% its the thermostat.
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10-23-2018, 06:36 PM	#12
Niart906 First Lieutenant 186 Rep 335 Posts Drives: 2017 M3, 2003 M3 Join Date: Feb 2015 Location: Dalton, PA iTrader: (0)	Looks like the thermostat is about $130, then add coolant and labor and that figure sounds pretty close. Maybe a bit high. Does your car actually get to operating temperature? Or does it run cold/fluctuate a lot? https://www.ecstuning.com/b-genuine-...t/11537598865/ __________________ 2017 F80 M3 - Mineral White/Amaro Brown 2003 E46 M3 - Jet Black/Cinnamon
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10-23-2018, 09:39 PM	#14
Billfitz General 9803 Rep 18,331 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	It will eventually get to operating temperature, or close to it, depending on the outdoor temperature. Catch-22 is the the colder it is and thus the faster you want to get heat the slower it is to warm, if it does at all. There are youtube videos how to change a thermostat. OEM will be really expensive, I'd go aftermarket. Even then figure about $100, as it's electrically controlled, and is nothing at all like $15 spring operated thermostats.
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10-24-2018, 05:29 AM	#16
bimmer456 Major General 3416 Rep 6,121 Posts Drives: 340i Join Date: Nov 2016 Location: Pasadena, CA iTrader: (0)	The engine doesn't need to be at operating temp for the heat to work as the heater uses a separate heater element and does not require coolant to be warm to work.
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10-24-2018, 09:26 AM	#20
Billfitz General 9803 Rep 18,331 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	The 340i parts list doesn't show electric heat assist, the LCI 328D does. My heat comes up a lot faster than my oil temperature too, usually within five minutes at 30F. The system probably allows flow of coolant through the heater core before it allows it through the radiator, for faster heating of the car interior, but I haven't come across anything definitive on that point.
	Appreciate 0 Quote

10-24-2018, 11:33 AM	#22
Billfitz General 9803 Rep 18,331 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	This is one instance where having the coolant temperature read out, rather than oil temperature, would be helpful.
	Appreciate 0 Quote