I just recently got a 99 BMW M3. I installed my Empeg about 2 weeks ago and it's working pretty well... I took a trip over the weekend and had some issues with overheating of the Empeg, though. We drove there Friday and the temp was about 50F for a 4 hour drive. No issues at all. I had the climate control set at 72-75F and all was fine. Coming back, though, it was about 40F (maybe) and about 2 hours into the trip, I got the high temp warning (I have it set to 59C). When I pulled the unit out of the sled it was very hot to the touch. I had the climate control at 80F. I felt inside the sled and it was extremely hot in the entire cavity. I let the Empeg cool for a bit and then put it back in and all was fine for the rest of the trip although I couldn't check the temp (I'd broken my encoder installing the light kit - damn super glue).

Well, today after repairing my encoder and finishing the light kit install, I also hooked up a fan I had installed a year or more ago. It ran the entire drive home. I had the climate control set at 75F and the Empeg was STILL running 43C after only a 45 min drive home from work!

Has anyone else had an issue like this with a BMW or any car and if so, anyone got a solution? I mean, the fan I have in is not a super high CFM fan, but I also had fan openings laser cut into the top for more ventilation (I had this done at a place I used to work a couple years ago). I am looking at building a temp controlled fan circuit but I do not tihnk it's going to solve the issue... and with winter coming up here where I am and the normal temperature sitting under 30F most of the time and needing to keep a warm car for my daughter, I'm needing a guaranteed solution.

Anyone have any ideas?

You CAN turn the temp sensor off with Hijack... but I'd rather do it the right way

Yes, I was being sarcastic. I havn't had a real problem with mine, but I'm not even sure if I'm using my empeg with a working temperature sensor at the moment. I don't know what the space situation is in the M3, but I assume there just isn't any ventilation at all. Is there any place to put a fan in the car that will direct air towards the empeg?

Matthew

I've just recently completed the install of my empeg into my Honda del Sol. With the heat set to 'full' it takes about an hour of highway driving to get the High-Temp warning.
There's not much room for air circulation in the console and, even worse, ducts on either side of the console are fed by channels on either side of the head unit- virtually ensuring a heated environment for any ICE.
For the short term, I'm thinking about a simple 12V fan and a switch. <shrug>
For the long term, I'm watching this board for good ideas...

So - turn off the temp sensor first. Then run the car. Then after a drive, examine what HiJack thinks is the temperature, and tell us here. The temp will determine the life of your disks.

It implies you have an issue with your install: you should have clear airways at each side and above the sled. Either that or one of your drives runs excessively hot.

Well... I hope I misinterpreted your slam of my install as one generally installs the radio where it was intended unless they want to go to a lot more work (and in many cases, a less professional look).

My BMW has the radio directly under a vent and directly above the climate control. The air to the sides is clear and the air above. The bottom, though, rests on the climate control. Although I DO understand what you're saying about it being open to air all around, I sincerely doubt that most installations succeed in doing this.

Previously I had a Honda CRX and an Acura Integra. The CRX had major heating issues as all of the glass and my climate didn't get along. It did not help that the radio with it's own power amp sat above the Empeg. I put the fan holes in specifically for that reason as I spaced the radio off from the Empeg chassis to allow some flow. BUT even though it had mostly free air around it, it still had overheating issues. So I tend to think that your suggestion is not the solution for everything in all cases. I had it in an Integra also and didn't have as many issues even when the radio did sit directly below it. When I removed the radio and went to an Empeg and Carputer set up and had the monitor mounted in a movable chassis the heating issues mostly disappeared.

Well, I intend to also use the same set up with the BMW and have the Empeg installed already. The computer is going in the trunk and the monitor mounts on a bracket next to the radio. My concern is that I haven't been able to lower the temp inside the Empeg like I could before. Even in the CRX where the radio heat was intensified, I was able to maintain a constant temp with the fan on. Currently, even with the fan on I am climbing constantly. It is NOT the hard drive as this issue has occurred with multiple hard drives I've had in the unit. And since I do have airflow AND 2 LARGE holes on the top panel and and still not pulling enough heat out, how do I lower it?

I had one of those hard drive coolers in it for awhile. It had 2 60mm fans and an aluminum heat sink that contacted the drive faces ( I KNOW this is not ideal... but it did work and did NOT ruin any of the drives). The holes in the top were originally cut to mirror this set up. It does NOT fit in well, though and is REALLY loud and I'd rather not return to this method... but I might have to. I mean, even with the drive today to and from lunch I raised about 10C

Well, if you thought that was a diss then I'm not sure I can be bothered to help further, sorry! Good luck with it.

As I remember, people with fairly recent model BMWs have mentioned this problem before. The only way it makes sense is that the hot air ducts for the vents are spewing hot air into the space behind the dash or that the ducts run very close to the empeg and are radiating heat to the empeg.

Spewing that hot air into the dash area sounds like a bad idea. Maybe there's a leak in the ducting somewhere? Can you check for that? If it's just because it's so close to a duct, maybe you could insulate the duct?

Rob... I was saying I was hoping I misinterpreted you as I DID take it for a slam... but it apparently wasn't meant that way... I am sorry. I was trying to clairfy the install, though.

I did reach in the space after removing the hot empeg and it was very warm in the whole area. I did not feel a leak but that doesn't mean there isn't one. I had not seen this as an issue before posted with BMW's but I can't read every post and really until about 3 weeks ago I was interested in Acura relatted items and not BMW's... I was hoping some of the other E36 people had either seen the same thing or had a solution...

I am thinking now that maybe the temp controlled switch to that hard drive cooler might be a solution. Before I had always constantly had it running and it was far too noisy. But if I were to only turn it on if the temp was over "x" then it might be more manageable. And I really think this is only going to be a winter issue with the car because if there is a leak in the ducting, the summer should leak AC air...

I don't have a BMW, but I'll toss this one out: When you had your system set at 80, did you have an open window or something, i.e., did your heater have to work really, really hard to keep the car at 80? My brother drives with the heat on and an open window routinely. He likes the contrast. More to the point, he likes the cold breeze in his face, and his wife doesn't want to be cold. This is the same one who woke up once with two inches of snow in his room. (Ok, just near the window, but still!)

-jk

No... being a girl I also hate to be cold so I had nothing on but the heater. The temp outside was in the 30's but I had been driving for 2 hours so the climate control SHOULD have leveled out by then... I mean, it shouldn't have kept the fan on and pumping heat in to maintain the temp.

I am almost wondering if the climate control itself having a VFD or LCD (maybe an LED... not sure) and it being constantly on is generating the heat directly up into the Empeg chassis...

No, that wouldn't produce nearly enough heat for that.

I have a 1997 E36 Coupe. I don't think I've had an overheat warning with this install yet. I did with my Integra a couple of times in the summer though.

What settings do you keep on your climate control? I tend to leave mine set on Auto - though at first I used to pick where the heat should exhaust from.

If I want to kick the temperature up very high I'll usually direct the heat to the foot wells and the windshield. This means there's either very little or no heat coming from the center console vents.

The space the sled fits into in the dash is stock apart from having removed some plastic from the very back depths (for better wire routing).

Bruno

I got the high temp warning (I have it set to 59C).

First things first... I really think that 59C is too high a setting. Something in the 50-55 range might be better, but of course that would make the alarm come on all that much sooner.

Here's what's happening to you. Your empeg is sitting in a cavity in the dash that may well be open to the rest of the world, but there is no real air circulation going on. So the heater ducts are radiating heat into that cavity, along with the lesser amount of heat produced by the empeg itself. The longer you run the heater, the hotter that cavity gets.

Now for the real irony: putting the cooling fan in your empeg only made matters worse, because the air temperature inside that cavity is warmer than the air inside the empeg. You're using your cooling fan to blow hot air through the empeg!

Another irony is that the colder the weather, the more your empeg is going to overheat, because your heating system compensates for the cold weather by raising the temperature of the air it is using to heat the car, and the cavity in your dash gets hotter the colder it is outside.

How do I know all this? Because I have exactly the same problem with my system. I am OK as long as the outside temperature is above zero degrees F. Below that, it becomes a balancing act to keep my empeg below 54 degrees C. I have found that by increasing the heater fan speed and decreasing the heater temperature setting to 65 degrees F (I am assuming your BMW has some sort of electronic HVAC system where you can set the desired temperature) I can keep my empeg running down to about 25 below zero. Beyond that, I have to pull the empeg out and let it cool down after an hour or less of play.

The best solution (one I haven't tried but maybe will some day) would be to install a small, quiet, low volume fan to circulate air through the dash itself -- exchange the quite hot air in that dash cavity where the empeg is sharing space with your heating ducts with the cooler cabin air. Wire it so that any time the heater blower is running, that auxilliary fan runs as well.

tanstaafl.

Yes... I use the "Auto" setting and have the temp usually set to 75-80 depending on weather. It's not been overly cold here other than the couple days in question

I set it to 59 based on really the fact that my old cars, the CRX in particular, ran warm and if I were to set it lower than that, in the summer I'd hit that in about 15 min of driving (black interior, lots of glass... bad combination. Even tinting the windows didn't help)

I tend to agree with you completely as I noticed that night it happened that the air in the compartment was horribly hot and stayed that way. But I have always configured the fan as a "puller" meaning it'd pull the heat out, but of course that air has to come from somewhere and warm air flowing over the components is better than hot air being blown in, I guess.

I just this morning pulled the noisy fan out (it rattled... bad bearing I believe) and will try my luck without a fan for a bit and monitor how things are performing. If issues continue (and it sounds like they will), I'm going to go back to the hard drive heat sink and have it controlled by a thermostat... once again pulling. But the CFM of those 2 fans is 37 between the 2 of them although that is free air and the empeg constricts the flow... but regardless... pulling even 18.5CFM over the components, even if warmer air is still MOVING air, should help with matters... these fans are just so darn loud, though... hope I don't have to go that route.

59C is only about 140F (not sure which is a more natural measurement to you). If it's really hot in there, it could easily be 59C. In which case, a fan isn't going to do you any good at all. I'd suggest looking into ways to cool your dash space myself. Some sort of interchange with the cabin like Doug suggested makes a lot of sense.

Unfortunately, that is easier said than done I believe. Most of the under dash is even shrouded by covers and the only easy opening to things that I know is the glovebox.

Considering this is a new to me car and much nicer than anything I've had before, I'd rather deal with the inconvenience of pulling the empeg out now and then rather than cutting up the dash... I mean, I did a bit of a less conventional computer install than I've seen on BMW's because I didn't want to ruin the sunglass holder and remove the OBC

I used to design things for the automotive industry and the product we designed was an under dash power steering motor for cars in Europe... the design criteria for under dash temp was like 75C if I remember correctly and this was meant to be absolute worst case for operation and 120C for storage. I find it hard to believe that the dash area would get near that temp under normal running conditions. Mind you that this particular electric motor was running 75A and 12V for lengths of time up to a min. If it passed, and it did, it seems like other less current drawing items would not generate more heat...

In reality it doesn't matter how much heat you're generating, it's the diferential between how much heat you're generating and how much you're dissapating. If nothing is getting through the dashboard, then any heat generated just builds up, increasing the temperature. In most cars, the area under the steering wheel in the footwell is open, so any heat generated by a motor would have somewhere to disipate to.

As other have pointed out, adding any sort of fan or heatsink isn't going to do any good if the surrounding air is just as warm. If your fan gives you any benefit from evaporative cooling you've got bigger problems. Your only option is to find a way to get air from the passenger compartment to the empeg. Any room for tubes to the footwell?

Matthew

No possible EASY way to get to the footwell... But I will have to VEHEMENTLY disagree with you about the air issue... I will clarify with a real world example:

Let's say the temperature outsideis 95 degrees and you are standing there... for argument sake we will take away the effect of the sun on your body. If you are then handed a fan which is blowing the same 95 degree air at your face, you're telling me it will not lower your facial surface temp even minutely?

Heat sinks in general remove heat by air flowing over fins... as long as the air being blown over the heat sink is LESS than the generated heat from the parts, then you will have a temperature drop with the fins that wouldn't be there without it... so now the argument is that the Empeg components are not generating the amount of heat as is present ambiently. BUT regardless, the fan example above applies.

It seems we've fallen into an argument over physics that seems to be opionated... I thank everyone for their advice, especially tanstaafr who has the same car and actually gave me something to compare to... I will do what's needed to cool it if it comes to that utilizing my various theories... But I don't see how anyone is benefitting from arguing over whether a fan blowing warm air does anything.

And actually... the power steering motor I was the designer on is up under the dash with little ventilation. And if the heater was on at the floorboards... heat rises... and guess where the heat is going to be sitting? Under the dash...

If you are then handed a fan which is blowing the same 95 degree air at your face, you're telling me it will not lower your facial surface temp even minutely?


Of course it will, provided that there is moisture on your face to dissipate heat through evaporation. But what if that fan were blowing 140 degree air at your face?

That's what you're doing with any sort of fan or heat sink on the empeg: you're feeding air into the empeg that is hotter than the components inside the empeg, and that is going to heat up the inside of the empeg, not cool it down, just like that 140 degree air blowing on you will heat up your face.

When you dry your hair with a hair dryer, do your hair and scalp become cooler?

This is not a matter of "...an argument over physics that seems to be opinionated." This is basic thermodynamics and there is no escaping the fact that if you pour heat into something, that something is going to get hotter! If you keep heating those hard drives to 59C (or more!), you are going to significantly shorten their life.

tanstaafl.

You are correct in your hair dryer analysis... but I am saying that if both air and components are at an equilibrium temperature (which they should be), then my fan at 95 thing applies...

Honestly no one one is going to convince me differently nor it appears am I going to convine anyone... Please let's drop this. WHEN I try my theory I will post my results. If I am wrong, i will definitely say so...

I'll pipe in as one of only a few E36 owners with empegs. I also have an E36 M3 (a real one though ).

I live in a fairly warm country (Australia) though. In winter we only get down to about 6 or 7C according to OBC. During summer, I've had the overheat warning come on at 55C (OBC reading 38C roughly). I changed it to 60C I think and haven't ever had it again including 40C days.

I set my climate control to 22-24C (both sides) and although it does a totally crap job of climate control, I don't believe it has any major effects on the empeg itself. The ducting above the empeg (although close) I don't think will do much even if the climate control is heating. Also note that unless you configure it away from "Auto" it will direct most warm air at your feet.

Well, human skin is usually moist. However, your empeg does not have sweat glands. So unless you plan to put a mister in there, too, I think you're wasting your time.

I would like to make one more explanation and then I'm done... no one is listening or thinking...

OK. The Empeg is a heat source. If I put it in my living room at an ambient temp of 74F and leave it on, it will raise to something like 90F after running for awhile. This discussion of temperature rise in open air has been exhausted before but I am not sure of the exact numbers but there IS a temperature increase. For this example, let's say it's 16F. OK... now let's raise the ambient temp to 90F... does the empeg still STAY 90F? NO! It is a heat source... it will be above 90F by some amount... let's stick with the 16F for comparison. So the Empeg is now 106F.

IF I were to take 90F ambient air and blow it on a heat source, the Empeg, which is running at 106, then there WOULD be a temperature drop. It would NEVER reach 90F because of the heat generation and losses, but it WOULD be less than the 106F

Now in my case, the Empeg was shutting down meaning the ambient temp PLUS the empeg heat generation was 138F. The temperature inside the dash console could have in NO WAY been 138F for safety reasons (as no matter how much they seal, there is no way to completely seal the dash so NO air gets out). BUT the ambient temperature IN the dash area PLUS the heat generated by the Empeg WERE 138F. ALL OF THIS MEANS THE AMBIENT TEMP IN THE DASH WAS LESS THAN THE EMPEG HEAT GENERATION. It HAS to be. So, taking cooler abient air, no matter HOW MUCH COOLER, and flowing that air over the components would HAVE to result in a temperature decrease in the Empeg. BUT it could only be lowered to the ambient in the dash with 100% efficiency... So it would be something above that.

What no one is taking into account is the HEAT GENERATOR that IS the Empeg. Ambient temp PLUS that trapped heat generated are what is measured by the sensor.

Please don't make me drag out my thermo books and do an example of heat generator and cooling effects... THINK!

Quote:
does the empeg still STAY 90F? NO! It is a heat source... it will be above 90F by some amount..

Hell, there is no need for Greenpeace to be protesting! Tony Blair should simply buy up all the empegs in the world as we have just discovered a new, self-perpetuating energy source!

Quote:
Please don't make me drag out my thermo books and do an example of heat generator and cooling effects... THINK!

I thought we were doing, us engineers and original designers of the product. Are you? My understanding of black body radiance concepts is obviously not the one you are working to.

I'm a bit ticked you have asked for help here on this board, and - basically - been rude and not prepared to either listen or adjust your thinking or viewpoint. I felt this immediately I started discussion further down the thread: this sequece of responses have confirmed my original gut feeling.

I can tell you for free here: BMWs are the hardest cars that the empeg is being installed into - read the regular troubleshooting and installs problem reports from various owners - but it is possible if you stick at it.

From my experience attempting to install in the dash of an older model three series, I noticed that there was simply no room, or air circulation in the dash column. The player I put in there continuously runs hot, far hotter than I or the owner are happy with. But it works. My own install ran cool when the empeg was above the second head unit I have installed: I reversed the install so that the empeg was under it, and it started getting pretty hot. My conclusion was that it is sensitive to convection space above the lid holes. Cutting a small slot in the panel between the two units reduced the temperature a lot, without the need of a fan.

Good luck: if you keep going like this, you'll piss off everyone here to the point where no-one else will be prepared to help.

So you're saying that a device that runs at 140F in an ambient environment of 140F will cause the temperature to go up?

I think Jemmi is asking a reasonable question: If the enclosed dash area is not as hot as the inside of the empeg, shouldn't we be able to move heat out of the empeg into that dash area?

Now, if the dash area (however small) where the empeg mounts does get as hot as (or hotter) than the inside of the empeg, all bets are off. It may just offer a delaying tactic.

-jk

If the inside of the dash is less hot than the empeg, then yes, of course you can reduce the heat of the empeg. But I thought we already determined that the fan wasn't helping and was actually making the problem worse. That would imply that the inside of the dash was hotter than the empeg.