1996 BMW 740

1996 BMW 740
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KING3428
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Engine Cooling problem
1996 BMW 740 V8 Two Wheel Drive 180000 miles

ok i just installed a cold air intake on my 96 bmw 740il the kit installed perfectly and all clamps and sensors fit no problem. i staed up and white smoke from exhaust. now it is cold outside but i let it run almost 10 full minutes with no change. engine is in excellent running conditoin. as i was completing a full tune up and last i did the cai. i rechecked my clamps and sensors and everything checks out. please this my daily driver and i need it in perfect running condition. what can i do to correct this> why is it blowing white smoke??
Mar 5, 2010 at 8:13 PM
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DR LOOT
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the first thing I would do is put it back how it was originally remove any modifications that you have done and see if it still blows white smoke.
Mar 6, 2010 at 12:04 AM
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DANAUTHIER
  • CAR REPAIR CONTRIBUTOR
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Dr. Loot is correct, the first thing to do is restore the air intake to the factory design and run to see if the condition corrects itself. After restoring the vehicle to the OE configuration, it may take some time for the "smoke to clear", so to speak. You may have to run it a while, even drive the vehicle, to be sure.

An aftermarket cold air intake system is designed to introduce more air into the engine's intake. Even with the OE sensors, the extra air can do a couple of things that may cause adverse effects. One, the excess air can cause the engine to run lean or,two, the excess air can actually draw extra fuel into the combustion chamber making the engine run rich...both could cause a white appearence to the exhaust, especially in cold weather.

OE engine intake systems are designed to facilitate enough air flow to allow an air to fuel ratio of 14.7 to one. This is the most effiicient mixture of air to fuel, to allow for power to fuel consuption for the vehicle and still remaining within EPA gidelines. There are companies that manufature cold air intake systems that will increase horsepower while maintaining this ratio.

Other providers do not do the research nessesary to maintain this ratio, they use the same basic design and just add ports for sensors. This qualifies them for sale in 48 states, allows them to state that the system is "designed" for a specific vehicle and engine,but does not nessesarily mean that they will work properly to maintain the air to fuel ratio nessesery for a specific vehciel and engine.

Listen to the Docs (no disrespect intended)...remove the modifications and also fully read the literature that came with the system, there may be a fix or a help line to call. You may find that they recommed a programing adjustment or a disclosure that something like this may happen.

Let us know what you find or if we can help futher.

Thank you,

Dan
Mar 6, 2010 at 12:54 AM
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