If the brakes are squealing, there's a good chance it is the brake pad wear sensor. A new design was implemented in January 2006 and can be identified by its green color.
Resources for the Repair and Maintenance of your 2004 BMW 645Ci
2004 BMW 645Ci
2004 BMW 645Ci Problems
2004 BMW 645Ci Recalls (Recent)
RepairPal Expert Overview:
The insulated connector for the positive battery cable may have been incorrectly attached to the trunk floor panel, which can lead to a loosening of the bolt connection. Loosening of the connection can cause an increase in electrical resistance and overheating of the cable connection, which could lead to a fire, even when the vehicle is not in use. As a precaution, owners are advised to park outside until the remedy has been completed. Dealers will secure the battery bolt cable connection as necessary to correct this concern.
RepairPal Expert Overview:
A circular retention clip at the quick-release fuel line coupling was inadvertently not installed. In the event of a severe frontal crash, the quick release coupling could separate, causing fuel leakage. Any fuel leak always increases the risk of a fire. Dealers will install a retention clip at the quick-release coupling on the fuel supply line. The recall began on July 5, 2004.
RepairPal Expert Overview:
The digital management control (EMC) unit may not have been produced according to specification. The engine may stall and not restart. As a result, a loss of power steering, and after repeated actuation of the brake pedal, a loss of brake power assist will occur. These conditions could result in a vehicle crash. Dealers will install a new (EMC) unit to correct this issue. This recall began on July 16, 2004.
2004 BMW 645Ci Questions and Answers
The passenger window control will move the window down, but not bring it up. What is wrong? Also, my key will lock the doors, but not open them. It will open the trunk, lock all doors and set the a...
MY AC COMPRESSOR BELT SNAPPED THE OTHER DAY AND I TRIED TO REPLACE IT MYSELF SINCE IM PRETTY MECHANICALY INCLINE BUT FAILED AFTER 2HRS UNDER THE HOOD,SO I THREW MY HANDS UP AND TOOK IT TO PEPBOYS...
I just wanted to know what the 50,000 mile service for my 2004 BMW 645 entailed?
ENGINE KNOCK NOISE AT IDLE OR 1000 RPM IN 4TH & 8TH CYLINDERS
The repair shop is telling me that the new fluid is $448 and @ $19.95/half liter that equates to approx 11.5 liters of fluid. Is this correct?
2004 BMW 645Ci Reviews
When it runs, this car is the Ultimate Driving Machine. The problem is that it does not run an average of 2 months out of the year, each year, since we bought it new in December of 2004. The repair file we have for this car is 3" thick. Just to name a few, we found out within a few weeks of owning the vehicle that both back wheels were cracked when we bought it. The washers around the ends of the coolant pipe running through the engine react with coolant, disintegrate and require a $12,000 repair at 80 to 90 thousand miles. A design defect in the convertible top drain line caused water to pour into the trunk onto the Logic7 amp and fried almost all of the speakers. The dealership had to replace each computer module. The oil pump simply leaks. Fixing it does no good because it starts leaking almost immediately. The secondary air pump lines broke at 80k, AC compressor went out at 90k miles, and alternator at 60k miles. The interior rubber covered plastic panels shed the rubber cover and scuff if you look at them too hard. The dealership agreed to replace them once but informed us that BMW would not do it again. In other words, BMW knows the interior panels are not fit for their intended purpose but used them anyway. Right side front lights have failed 3 times faster than any other area. Yes, all of them. Of course, the design defect with the headlights probably contributes to the problem. The seal for the $1,500 headlights dry rots at 50k miles, the headlights then condensate and/or flood, short and cause damage all over the place. We have replaced the Xenon controller, ballast, headlight bulb and even the wiring inside the headlight because it dry rotted and caused another short. The alternator seal leaks. Repairing it does little good because after 10k miles, it leaks again. The expansion tank sprung a leak. The coolant reservoir sprung a leak. An ignition coil failed. The small, hard plastic, coolant line that runs over the radiator sprung a leak about every 10k miles until I wrapped it with a heat shield. We have had to replace the battery three times two of which were at a discount because the batteries were well within their expected lifespan. My wife is terrified of the seat heater after an incident wherein it quickly heated to a high enough to first degree burn every part of her body touching the seat. BMW recalled these same seat heaters in other models but denied any problem with them in the 2004 645ci. Aside from the leak from the design defect with the convertible top drain line, the trunk leaks. The convertible top leaks from time to time. The engine leaks oil everywhere after about 70k miles. The plastic housing for the window lifter controls and around the gearshift wears like a cheap suit. The right rear emergency brake fell apart and nearly caught the wheel on fire. Multiple sensors have failed. The AC belt broke at 50k miles. Various hoses have prematurely broken. The computer is slow. The navigation is a DVD, and if you want to update it, get ready to take out a loan. It is idiotically expensive. The entertainment and communications system is virtually impossible to update without spending $10k. The run-flat tires are four to five hundred a piece, last 30k miles, and cannot be patched if you pick up a nail. The brakes produce so much dust, the light gray front rims are black within 1k miles after washing them. The left front wheel bearing went out. Some valve in the transmission went bad because it was designed wrong. Don't unplug any electrical connectors because they dry rot and will almost assuredly brake. The steering wheel clicks when turned in cold weather.
The list goes on and on and on and on. We are afraid to sell it because something will more than likely brake right as the buyer drives away and will sue us for fraud. Consistent with the quality of their product, BMW won't stand behind it. We have contacted them about the shocking amount of problems with the car, and BMW's response is basically, "It's your problem." BMW - The Ultimate POS.
my headlight has mousture in it is there anyway to repaire it without spending 2000 to replace it with a new one plse someone who has had this problem get bak to me thnx
Tires wear pretty fast..idrive takes some getting used too. BMW drives like a dream.
Brake recall - part on back order for months
constant tire problems - flats and cracked rims - this car does NOT like NYC driving - it is unforgiving
SNOW - take a bus or pray!