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Discussion Starter · #1 · (Edited)
So I was driving to Dallas last night from my house, (about 30 miles) when I noticed that my a/c system wasn't really blowing hot air. I had the temp for both zones set at 85 and it didn't seem to matter if I moved it up or down 5-10 degrees. If I turned the center vent temp dial to full hot it would heat up some, but it didn't seem like enough heat for full hot. A possibly important piece of info here is the SES light I had last week, code 69 on my peake scan tool. (engine coolant temperature, plausibility) The code turned off when I filled up the gas tank. The last time I got gas was in december since my car was out of action for 3+ weeks while I was replacing the clutch. Also I need to replace the plastic panels under the front bumper, aka the exploding curb boxes. I know the outside air temperature sensor is located in the pass cover.

So, number one, is something amiss? I haven't had the car long enough to experience all the norms for things like a/c temp response.

If something is wrong, where should I start? ECT switch, thermostat, something else? I do plan on replacing the front bumper covers soon anyway.

As always, thanks guys! :cheers:

-Brian
 

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Hi Brian,

sounds like it is your thermostat, what was the temperature gauge indicating?

It could also be your FSU - final stage unit (or resistor), but that, I think, is more to do with the fan speed - does your fan work correctly? if you press the button to demist the front windscreen does the fan blow at full blast?

Richie.
 

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Discussion Starter · #3 ·
The fan seems to work fine. The temp gauge sits at the first dot when warmed up.
 

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I'd guess your thermostat is stuck open and is causing your vehicle to run cooler than normal.

This, in turn, will prevent your heater core from coming up to temperature and will cause your car to blow warm, but not hot, air.

d-
 

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Discussion Starter · #6 ·
Yeah, that makes sense. Is that SES code I got pretty much the only one for a stuck thermostat?
 

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Yeah, that makes sense. Is that SES code I got pretty much the only one for a stuck thermostat?
There is one for Coolant Temp Sensor as well, but I believe that is for the sensor itself.

Code 69 basically means Conflicting Information at the DME. That could be an oil temperature reading well above the water termperature, or an abnormally high or low water temp reading as well. I emphasize reading because the code doesn't distinguish between bad data and something physically out of whack.

Given that you also have loss of heat, however, something is clearly affecting your heater core, and the only thing that could physically affect the heating core would be low water temperature. Thus, I would suspect your thermostat first.

Doug
 

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Yeah, that makes sense. Is that SES code I got pretty much the only one for a stuck thermostat?
As everyone says, it all points to your tstat.

Unlock your on board computer, test 7 is water temp and 16 is oil temp, both in Celsius. You shoud see close 80 degrees on each one.

If your water temp is at the first dot, I suspect water temp is low 70's.
Regards,
Jerry
 

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Discussion Starter · #12 ·
Ok, so all joking aside. I ran the tests today and this is what I found: core temp was 76 deg C and oil temp was 84 deg C. Ambient temp was 66 deg Fahrenheit.

How does this sound?
 
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