[K.M]

Hi,

Recently purchased a 2007 328xi coupe.

I have an issue with the engine heat. The temperature gauge is always in the middle of the range, which I assume is normal/intended, however the very loud air intake is always on. Turning on the ignition from a cold start in the garage always ensure the sound of an airplane taking off...

Not only the sound, but the engine runs very hot. Even after a short journey, the engine will stay too hot to touch for HOURS. I do not live in a particularly hot climate either.

My coolant was replaced very recently, among other things.

The worst part? The heat managed to melt my BMW roundel off the engine, making the hard plastic very bendable when I noticed it was curled/disfigured due to the heat. See below.

Keep in mind: the roundel was carbon fiber and aftermarket, but was in good shape when I bought the car. Also, I did recently go on an 8 hour road trip, maybe that's when it happened?

Do these non-turbo engines commonly run hot, always?

[stewey]

No I don't think these engines run hot. All engines of course generate lots of heat and will stay warm for a long time after running. It is unusual for your fan to be running full blast from a cold start. I don't know what would cause that maybe someone else will chime in about that.

You might want to try enabling the digital temperature read out on your instrument cluster:

That way you can see what the actual temp is. You should also pull codes and see if there are any clues there.

[K.M]

Originally Posted by stewey

No I don't think these engines run hot. All engines of course generate lots of heat and will stay warm for a long time after running. It is unusual for your fan to be running full blast from a cold start. I don't know what would cause that maybe someone else will chime in about that.

You might want to try enabling the digital temperature read out on your instrument cluster:

That way you can see what the actual temp is. You should also pull codes and see if there are any clues there.

Thanks for the reply.

I'll see if I can get the digital temp read for the coolant tomorrow. Also, I am working on getting the Carly app & OBDII adapter so I can read codes from the car.

[stewey]

Sounds good. Just be careful until you get to the bottom of this. Overheating can cause damage $$$

[K.M]

Originally Posted by stewey

Sounds good. Just be careful until you get to the bottom of this. Overheating can cause damage $$$

I'll do that. I had a pre-purchase inspection recently and noting was found, but that doesn't go in depth to the components. What temp should I be looking for in terms of the coolant?

[refugeeofwar]

You can easily search the normal operating parameters of the engine online and it may even be in the owner's manual. I have the 2011 which has a temp gauge and it sits around 100-105 C when warm. Even driving fairly hard on a warm day I've only seen around 110 C.

As for it staying hot for hours, that's fairly normal. Speaking from experience, if you have run an engine up you typically have to wait like 2-3 hours before you can touch it and even then you have a hard time not burning your hands if you don't have gloves on. Engine blocks absorb and retain heat. Obviously the magnesium and aluminum in our block dissipates heat much faster than say a cast iron block, but it's still a huge hunk of metal and will still take a long time to cool down, from even normal running temps.

[hassmaschine]

yes, actually they are designed to run hot - up to 112c. But, your fan shouldn't come on that much I don't think, it does sound like something is a bit off. what is the actual temp that it's running at? you will get a yellow overheat warning at 120c and a red one at 125c, so it can't be that much warmer than "normal".

And the engine does seem to stay warm for a long time. I think this was intentional.

[Delta0311]

"Turning on the ignition from a cold start in the garage always ensure the sound of an airplane taking off..."

Sounds like a failing water pump or thermostat. Get a BT tool and scan for codes.
07 328, if the pump was never replaced then it is a safe bet that it is on its way out...

[TheSt|G]

Originally Posted by hassmaschine

yes, actually they are designed to run hot - up to 112c. But, your fan shouldn't come on that much I don't think, it does sound like something is a bit off. what is the actual temp that it's running at? you will get a yellow overheat warning at 120c and a red one at 125c, so it can't be that much warmer than "normal".

And the engine does seem to stay warm for a long time. I think this was intentional.

+1

These engines are designed to run hot for better efficiency.

[K.M]

Originally Posted by refugeeofwar

You can easily search the normal operating parameters of the engine online and it may even be in the owner's manual. I have the 2011 which has a temp gauge and it sits around 100-105 C when warm. Even driving fairly hard on a warm day I've only seen around 110 C.

As for it staying hot for hours, that's fairly normal. Speaking from experience, if you have run an engine up you typically have to wait like 2-3 hours before you can touch it and even then you have a hard time not burning your hands if you don't have gloves on. Engine blocks absorb and retain heat. Obviously the magnesium and aluminum in our block dissipates heat much faster than say a cast iron block, but it's still a huge hunk of metal and will still take a long time to cool down, from even normal running temps.

Sorry, are you talking about the coolant or the oil?

Again, my oil gauge is constantly in the middle, which is 250F.

As for the staying hot, thanks, that makes sense and reassures me a bit

Originally Posted by hassmaschine

yes, actually they are designed to run hot - up to 112c. But, your fan shouldn't come on that much I don't think, it does sound like something is a bit off. what is the actual temp that it's running at? you will get a yellow overheat warning at 120c and a red one at 125c, so it can't be that much warmer than "normal".

And the engine does seem to stay warm for a long time. I think this was intentional.

I get no overheat warning so that's a plus, never have. I'll get the actual temp a little bit later, currently recovering from dental surgery and doctors suggest I don't drive on Vicodin

[K.M]

Originally Posted by Delta0311

"Turning on the ignition from a cold start in the garage always ensure the sound of an airplane taking off..."

Sounds like a failing water pump or thermostat. Get a BT tool and scan for codes.
07 328, if the pump was never replaced then it is a safe bet that it is on its way out...

Oh lord, I don't believe it has been replaced. I was dreading this day

[Delta0311]

Originally Posted by K.M

Oh lord, I don't believe it has been replaced. I was dreading this day

Yeah I'm positive your pump is failing, hence the radiator fan running at full speed right when you fire up the car.

[Soul_Glo]

One summer I hit 150 C. There were no warning lights. I drove straight to the dealership and they said that it was normal. I went to a second dealership and same again. It makes no sense to me as engine oil starts to break down at 124 C. Since then I have never had it again.

I would suspect the water pump and thermostat though.

[K.M]

Originally Posted by Delta0311

Yeah I'm positive your pump is failing, hence the radiator fan running at full speed right when you fire up the car.

Originally Posted by Broken_Gearbox

One summer I hit 150 C. There were no warning lights. I drove straight to the dealership and they said that it was normal. I went to a second dealership and same again. It makes no sense to me as engine oil starts to break down at 124 C. Since then I have never had it again.

I would suspect the water pump and thermostat though.

Water pump seems to be an extremely costly repair when out of warranty. Any tips on getting that cost down? Even buying a cheap extended warranty could be better than shelling out the $1k+...

[Delta0311]

Originally Posted by K.M

Water pump seems to be an extremely costly repair when out of warranty. Any tips on getting that cost down? Even buying a cheap extended warranty could be better than shelling out the $1k+...

Get the parts yourself and find a good mechanic. This should reduce the cost quite a bit.

[Tom Droze]

My oil temperature always settles in at 250 degrees Fahrenheit (121 degrees celcius) during daily driving. When I did a track day last March my oil temperature reached 280 degrees Fahrenheit (137 degrees celcius), but I was monitoring my coolant temperature via a Bluetooth ap and my cell phone that plugged into my OBDII port, and my water temperature never got any hotter than 220 degrees Fahrenheit (104 degrees celcius).

[refugeeofwar]

Originally Posted by K.M

Sorry, are you talking about the coolant or the oil?

Again, my oil gauge is constantly in the middle, which is 250F.

As for the staying hot, thanks, that makes sense and reassures me a bit



I get no overheat warning so that's a plus, never have. I'll get the actual temp a little bit later, currently recovering from dental surgery and doctors suggest I don't drive on Vicodin

Yeah man, that's what I was talking about. Mine has an oil temp gauge. If your coolant, which cools your oil (and engine) is hotter than spec, then I would think the oil temp would reflect that. Either way, I think by now you have enough input to point you in the right direction. So yeah, running hot not so great, but taking hours to cool down is nothing to worry about.

[hassmaschine]

Originally Posted by Broken_Gearbox

One summer I hit 150 C. There were no warning lights. I drove straight to the dealership and they said that it was normal. I went to a second dealership and same again. It makes no sense to me as engine oil starts to break down at 124 C. Since then I have never had it again.

I would suspect the water pump and thermostat though.

150c oil temp? because that's something different. there is a yellow & red warning indicator for oil temp, but it's not set to the same threshold.

Coolant definitely is 120/125c.

there are also separate maps that cut power based on oil & water temp.

[Soul_Glo]

Originally Posted by hassmaschine

150c oil temp? because that's something different. there is a yellow & red warning indicator for oil temp, but it's not set to the same threshold.

Coolant definitely is 120/125c.

there are also separate maps that cut power based on oil & water temp.

As far as I know those are...
112 deg C ECO Mode
105 deg C Normal Mode
95 deg C Med output mode
80 deg C High output mode

Fantastic article on the N52B30 if not already seen/posted here: https://www.google.com/url?sa=t&rct=...cx3Q3d43VgPQdw

Yes... anyhow at the risk of thread jacking. Both the dealerships turned me away as there was no fault code/warning. As far as I know heads can even warp at 140 C if coolant is not circulating properly. If they wanted to make money out of me then I could have easily lined their pockets... there was a thread on here last year or the year before where a guy saw 140 C oil temp on a track day... I found it as I was researching my concern... it has never happened again though

[Soul_Glo]

Originally Posted by Delta0311

Get the parts yourself and find a good mechanic. This should reduce the cost quite a bit.

+1

[hassmaschine]

Originally Posted by Broken_Gearbox

As far as I know those are...
112 deg C ECO Mode
105 deg C Normal Mode
95 deg C Med output mode
80 deg C High output mode

Fantastic article on the N52B30 if not already seen/posted here: https://www.google.com/url?sa=t&rct=...cx3Q3d43VgPQdw

Yes... anyhow at the risk of thread jacking. Both the dealerships turned me away as there was no fault code/warning. As far as I know heads can even warp at 140 C if coolant is not circulating properly. If they wanted to make money out of me then I could have easily lined their pockets... there was a thread on here last year or the year before where a guy saw 140 C oil temp on a track day... I found it as I was researching my concern... it has never happened again though

I was talking about the coolant temp warning threshold, which is 120c for yellow and 125c for red.

I bumped my yellow threshold down to 115c.. for like an extra 5 seconds of warning.

I've wondered if there would be any power to be gained running the engine hotter at full load. maybe not 112c but perhaps 90.. but it might just make it knock earlier and lose power.