myfirstbmw530

i have 05 530i. so 3 days ago, all of sudden when i started the car, i got a check engine light on.... i have called the dealer yesterday and they said it had to do something with the gas cap not on proper. they said to check it and the light should go off today when im driving.... anyways, i didnt.... is increased emission serious? can that effect my heater too? last week the heater came on after 15 minutes and now after 30 minutes, its still giving me cool air......One person on bimmerfest said it can be the water pump.... can it be? i did buy the 2 year warrant when i bought the car. hopefully that will fix my problem.

jaycal3

A few points: You should have the codes read so you know what the "Increased Emissions" warning is referring to... could be any number of things. Check your iDrive for heating/cooling settings and distribution. Often times its user error as to why it is too hot or cold... As for the Water pump... for a too hot/too cold issue?? Really?

You have a warranty. Use it.

BimmerFan52

Generally the water pump itself cannot not generate an increased emissions code or prevent heat to the cabin but a thermostat stuck in the open position can. Also, a failed thermostat heater coil can generate an emissions fault.

Modern BMW thermostats include a heater coil. The thermostat operates based upon wax reaching a melting temperature and allowing the spring in the thermostat to open the valve. Under certain engine conditions the computer may send current to the heater coil to cause the wax to melt faster and start water flowing sooner.

During start-up the engine computer diagnostic software tests the circuit and will sense that the coil is missing from the circuit and generate an increased emissions fault.

The coil can be tested by removing the electrical connector on the thermostat and measuring the resistance between the two brass conductors on the thermostat connection. 16 ohms will indicate an intact coil. A measure of infinite resistance (1 on the multimeter) indicates the coil has failed (coil wire broken).

Although a failed heater coil will not affect normal thermostat operation the increased emissions fault will only be removed by replacement of the thermostat.

Your problem may be a thermostat stuck in the open position, delaying engine warmup and heat to the cabin. When you start the engine you should be able to feel whether there is water flowing immediately through the hose from the thermostat that goes into the engine block, which would indicate a stuck open thermostat.

mikegreen

bimmerfan52, found this when searching.. I have similar issue.. Could you point me to where the thermostat heater coilis located to ohm it out?

thanks for the info!
-mike

BimmerFan52

Hi Mike,

Remove harness connection to thermostat and place two leads of multimeter to points shown.

Regards,

Bimmerfan52