My heat is set to hi with fan at fifty percent, its definitely warm but not as hot as last winter/as it should be. Any ideas? Anyone have this happen to them?

 

UPDATE: I drove the car a little harder than usual yesterday, and the air blowing out was much "hotter". Any thoughts?

 

You could have some crud built up or caught in your heater core which is preventing proper coolant flow. When I bought my car used, the previous owner, or perhaps the stealership, used stop-leak on the radiator. My heater core now needs yet another back-flush to clean it out...after I've already done two flushes and a replacement core. :(

It does not sound like yours is as bad as mine... it's hard to tell.

 

Was your engine temp gauge at the normal level yet? Have you looked at your cabin air filter? It's under the passenger side dashboard.

 

The car is on its thirds core...and cabin filter replaced two months ago. Temp was at normal level, but it did need to heat up from a cold start. Still once at nominal level should the heat be consistent?

 

Yes, your temperature should be steady. The thermostat's job is vary it's orifice size to go from closed to fully open as the engine's cooling needs change, in order to maintain an even coolant temperature, and thus an even engine temperature. And, as a side effect, a consistent supply of waste heat for heating the car interior when desired.

Assuming the air if flowing well (i.e. the heater core is clear and the cabin filter isn't clogged, and the ducts don't have a mouse wedged in there -- don't laugh it happens!), then the obvious thing that would cause inconsistent heating would be a thermostat that is getting stuck closed some of the time, or otherwise failing to open and close to maintain an even coolant temperature. But also check the coolant level; that's certainly relevant. Google advice on how to test a car thermostat.

 

When you say it's on it's "thirds core" do you mean the heater core was replaced 3 times? Why? Leaks? Overheating?

The stock thermostat on an R50 is set to 195° F. Did they reaplace your thermostat to combat an overheating problem? O'Reilly auto sells an $8.49 alternative temp thermostat for the Mini that's set to only 160° F. If that were installed since last winter, you'd have less cabin heat. You'd need to go back to a stock thermostat to get the level of heating you got before.

Your engine fan kicks on at low speed at 221° F and at high speed at 234° F. It stays on at high speed until it drops down to 230° F. If the temperature reaches 240° F, your dash overheat warning light comes on. The fan also turns on at low speed when the AC starts and the AC pressure is 8 bar, and goes to high speed when the pressure is 18 bar.

All of this can be diagnosed by looking at your temp gauge while driving around normally once the car has time to warm up. The gauge should move to the usual spot, the middle of the scale, and stay there. If the temperature is constantly bobbing around, rising when you accelerate, and cooling down when you coast, or never reaches the middle of the scale, you've got a cooling problem.

The thermostat is probably faulty. Or step out and listen for the engine fan. If your fan is on -- or on high -- when your temp gauge is not saying it's warm, then the fan is stuck on, or turning on too early. Which could be a temperature sensor problem, or an ECM problem. An AC problem could also make the fan stay on.

 

Inadequate heat from the heater, or heat that comes and goes, is most likely low coolant.

If the air side of the heater core was obstructed the flow of air would be poor.

Clogged coolant passages in the heater core could also lead to poor heater performance. Given the age of even the oldest MINIs, you would have to have never flushed the coolant to get a core clogged with corrosion. Or put in cheap standard coolant or stopleak, then proceeded to neglect the system again.

Dennis has good points about the thermostat.

When was a coolant flush last performed? Use only the BMW extended life coolant & distilled water.

 

OK guys so here's an update...

Core and thermostat both replaced 12 March at MINI of Baltimore. I topped off coolant maybe 1/2 cup or so missing, and now its even colder air coming through! AHHH!! My fan doesnt kick on anymore since the weather has cooled off, I do feel the core get really hot after the car warms up. The temp gauge gets to the middle mark and stays there...im really frustrated as to this problem...

Thanks!

 

As a sanity check, does your engine fan come on low when you turn on the AC? It's probably OK, but can you find out if they put in a 195 deg thermostat, or a colder one?

Do you have the IHKS manual system? The one with three big *****. Or the IHKA automatic system, with one big **** in the middle where you set the desired temp?

When the car is warm, and it's warmer in the cabin than outside, you should feel warmer air coming out when you choose recirculated mode instead of fresh air mode. In fresh air mode, you're going to feel not as much heat, since it's heating up the cooler outside air. If it makes no difference, then the problem could be that the fresh air flap is mechanically blocked, or broken, or the controls to the flap are failing.

If it's the automatic system, there is an interior temperature sensor and a heater core temperature sensor. If either of those is feeding faulty data to the IHKA control module, then it might think it's warmer inside than it really is. Or it thinks the heater core is warmer than it really is. Or the IHKA control module is bad. I think to troubleshoot that stuff you'd have to plug in BMWs diagnostic harness.

 

I have the automatic system, i just dont understand how one day its good and the next time its not. Ill call and ask what they put in tomorrow. Could I have blown a fuse somewhere? Maybe I should check all the fuses in the daylight as well?

 

Oh and the air is still warmer than outside air...

 

Sure, I'd check the fuses. Always worth checking that. So you're saying when you click the recirculate button, it's warmer than when you use fresh air?

All all that leaves is one of the two temperature sensors or the control unit. If it was one of these electronic components, it would make sense that it was working fine one day and then quit. Something burned up or shorted out, and that's the end of it. Or it has a faulty connection that intermittently works and fails at random times. Electronic problems are a nightmare sometimes.

 

Any ideas as to where to start?

 

The heating is controlled based on inputs from the heater core temperature sensor and the interior air temperature sensor. But the air conditioning only relies on the interior sensor. And the solar sensor. So if you run the air conditioning and it behaves as expected, then the interior temperature sensor is probably good. Set the interior temperature to various levels and see if it blows the expected amount of cool air. That would eliminate the interior temperature sensor as a problem, and would also indicate that the control unit is not completely messed up. Wear a jacket.

I'm still assuming the volume of air flow is normal. The problem is just that the air isn't warm enough, right? Because that eliminates fan issues, blockages, and there servo motors that direct the air around the duct system.

All that's left is the heater core temperature sensor, which runs about $30 to $40 online. Replacing it doesn't require taking apart too much of your dashboard, so it's not terribly painful to put a new one in and see what happens.

Or you could just take it to a shop with some expertise in Minis, and the right test equipment, and have them troubleshoot it. That would probably run $100-$200, plus the cost of the repair itself.

Before doing either, I'd go back to square one and review all of the assumptions we're making. Especially the one about air flow. And that your engine temperature is normal, the coolant is good, and the thermostat is running at the OEM 195 degrees.

 

Sometimes when I get to the point you are at I bite the bullet and take it in to be serviced. I make it clear that I just want the problem diagnosed, not repaired. Then I listen to them tell me what is wrong. If I can make the repairs then I do it, if not, I may have that garage do the repair or I may take it to another garage or dealer depending on the information I find out. Or you can authorize a certain amount of diagnosis time. Tell them to spend an hour or two diagnosing but no more unless you ok it.

 

ok so the plot thickens...i go to turn on the a/c and the condenser doesn't want to kick on...AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH HHHHHHHHHHHHHHHHHHHHHHHHH

 

this make me think this is an electrical issue.

 

I noticed two previous threads you posted, in 2009 and 2010, for AC problems, and for heat problems before this. So there must be some root cause with this car that hasn't been found yet. I'd probably not take it back to the same ones who fixed it before, since they seem to have missed what's really going on.

 

youd think for 1400 bucks mini of baltimore wouldve been able to fix this once and for all...i guess not :(

 

the fan is coming on "hi" after about a forty mile trip, i cant figure this out but where would the electric fuse be for the condenser?

 

I'm not sure why you think it's a fuse. On fuse panel 2, by the pedals, F29 is the AC control panel. F31 is one of the the heating and AC blower fuses. On fuse panel 3, by the left strut tower, FL1 includes the general module, heating AC blower again, and the cigarette lighter. FL9 is the engine cooling fan. FL11 is, once again, the heating and AC blower. F08 is also the heating and AC blower, and power steering cooling fan. Any one of those could interfere with the fan working.

But I thought lack of air flow wasn't the problem. It sounds more like intermittent random failures. Which points to the control unit itself. That would explain why so many heating/AC problems have recurred over the years.

I'd focus on finding a good shop in your area that knows how to troubleshoot this.

 

I just cant figure this out it irritates me, and there isnt any shops in baltimore that want to touch MINIs

 

On a justa, they can be tough to get air bubbles out...i wonder if there is a bunch of air in the core...the fact you suddenly had to add coolant means it went somwhere, or it burped some air out, letting in more coolant...
I know one independant shop that uses a preasure bleed system on justa's to prevent this issue....
I'm thinking first thing to look at is the thermostat....the system will get rebleed after that install....
next, simply run the heat on manual modes...
Set to max, and adjust the fan speed...take the auto controler (mostly) out of the loop...
Next, find a shop, other than a dealer to wotk on the car...perhaps a day trip up to philly?! (Helix)
Get the car fixed...maybe add some performance goodies?!

 

PS
Perhaps the terminology has you mixed up...
The condensor is just the big radiator like thinggy by the rad...it is passive just like the other part under your dash....the compressor is belt driven, and does get activated electrically (clutch). Then depending on pressures, the radiator fan may be turned on to enhance airflow to keep the system working properly....