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View Full Version : 545i Loud squeaking noise coming from engine on cold start ups?


Kalil147
06-20-2012, 09:36 AM
Every morning when I start my 545i. I hear this loud squeaking noise coming from the engine. It goes away after engine is warm. I can't tell if its coming from the timing belt, or the engine. My 545i is a 05 with 70k miles. After about 5 minutes it goes away. Car runs perfectly, idles fine. Has anyone experienced this issue?

pcy
06-20-2012, 10:26 AM
drop the drive belt and run the engine for few seconds and see if the squeak is still there. By doing that, you can isolate if the problem is internal to the engine or one of pullies is causing the noise.

While the belt is off, and the engine is OFF, spin each of the pullies (power steering, water pump if applicable, AC compressor, belt tensioner and see if any of the pullies have a 'play' in them or making any noise. They should spin smoothly without any wobble/noise.

Kalil147
06-20-2012, 01:09 PM
I just did it but it didn't help much. Engine sounded awful and preferred to put it back together. I feel like it might be the water pump or belt may be slipping. Can it be that I just might need new belts?

borderchris
06-20-2012, 03:06 PM
Every morning when I start my 545i. I hear this loud squeaking noise coming from the engine. It goes away after engine is warm. I can't tell if its coming from the timing belt, or the engine. My 545i is a 05 with 70k miles. After about 5 minutes it goes away. Car runs perfectly, idles fine. Has anyone experienced this issue?

Your car doesn't have a timing belt; it has a timing chain. You most likely need a new tensioner and possibly a new serpentine belt. Check the condition of the AC belt as well.

Kalil147
06-20-2012, 05:37 PM
I turned off the AC in the morning and squeaking continued. No other choice but to take it back to the stealership. :( Ill post the results

nyoung
07-12-2013, 06:31 AM
Hello,

I am having the same problem. Please tell me what your remedy was.
Thanks!

Bad Debt
07-12-2013, 07:51 AM
Your car doesn't have a timing belt; it has a timing chain. You most likely need a new tensioner and possibly a new serpentine belt. Check the condition of the AC belt as well.

This is the correct answer. While you are there change your water pump if you haven't already.

bimmerfan52
07-12-2013, 09:43 AM
I turned off the AC in the morning and squeaking continued. No other choice but to take it back to the stealership. :( Ill post the results

As previous posters have stated, the most common cause for the squeaking or squealing you describe is the drive belts (serpentine or AC belt).

The serpentine belt is driven by the crankshaft vibration dampener pulley to turn the water pump, power steering pump and alternator. In addition to driving the water pump, power steering pump and alternator pulleys, the belt is guided through its path by by idler pulleys (no function other than to guide the belt) and the tensioner (a spring loaded idler pulley used to set the final tension or "tightness" to the belt).

The belt itself or any of the total of seven (7) components the serpentine belt touches - 4 pulleys, 2 idler pulleys and the tensioner, can be the source of the noise.

As a previous poster recommended, remove the serpentine belt and run the engine for 15-20 seconds (NOTE: Mark the rotational direction of the belts prior to removal and if they are to be reinstalled keep the same rotational direction). If the squealing is gone then you can say definitively it is being caused by the belt or one of the seven components. Then begin rotating each component by hand until you find the culprit.

As a previous poster stated, the most common cause of noise is failure of the tensioner, followed by failure of an idler pulley, followed by one of the components that is driven (water pump, steering pump, alternator) exhibiting bearing failure noise.

Once you located that item I suggest you replace both belts, the tensioner and idler pulleys.

From your post it sounds like you removed the serpentine belt and the squealing continued.

If while the serpentine belt is off the squealing continues the removal of the AC belt to test for noise is required. The AC compressor on the 545i is clutchless, meaning that the compressor is turning all the time, so the fact that the AC is on or off will not change the physical rotation of the the AC compressor.

CAUTION: The AC belt is a stretch belt and does not include a tensioner. A special tool is provided by BMW to install the belt and without it, unless you have had a good deal of experience handling automotive belts it is a real PITA to install.

If neither belt or the components driven by them are the cause of noise then we will all say a prayer for you as your noise is internal to the engine.