My engine light comes on on the second start of the day. It doesnt come on at the first start when the engine is cold. Its the BMW 2.5 diesel engine. Starts normally from cold but when its warm it runs very fast for about a second and then settles to normal rpm. Very black smoke for the second it runs fast. May be a sensor........anyone have any ideas?

John

aquila787 said:

My engine light comes on on the second start of the day. It doesnt come on at the first start when the engine is cold. Its the BMW 2.5 diesel engine. Starts normally from cold but when its warm it runs very fast for about a second and then settles to normal rpm. Very black smoke for the second it runs fast. May be a sensor........anyone have any ideas?

John

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Take a look at the connections to number four injector make sure they are clean. Also connections to ECU temperature sensor. Is your vehicle fitted with a hot start unit? You will know this if the glow plugs come on when engine is warm.

Where is the ECU temperature sensor. The car has the heater plugs. I dont know if they come on while the engine is running. I know I hear a strange sound while its running(not all the time......it comes and goes) The heater plug light doesnt come on while the engine is running. The heater plugs may not be working. I got caught by a dealer supplying laundered diesel. The fault was there before the laundered diesel though.

John

aquila787 said:

Where is the ECU temperature sensor. The car has the heater plugs. I dont know if they come on while the engine is running. I know I hear a strange sound while its running(not all the time......it comes and goes) The heater plug light doesnt come on while the engine is running. The heater plugs may not be working. I got caught by a dealer supplying laundered diesel. The fault was there before the laundered diesel though.

John

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If you have a hot start unit, glow plug lamp will come on when you switch ignition on when engine is hot. If they don't you have not got one. ECU temp sensor is on side of engine under manifold there are two, one for dash gauge and one for ECU. ECU one is nearest to FIP.