Rattling from front of engine, but does NOT rattle when I turn.

hankcah · 03-16-2016, 07:55 PM

I have a rattle noise that was intermittent, but now happens on startup. Happens regardless of the Heat or A/C on/off.

It was rattling while I was pulling into the garage space, BUT it goes away slightly when I turn the wheel. My first thought was the power steering pulley. I think I had this replaced this past year, but not ruling it out. Had waterpump/thermostat replaced recently and had a hose disconnect, leaving me stranded. Would this have boiled the pulley or worn it down??

Could it be the cooling fan? Would you spray some WD-40 on the pulleys, or would this lead to an infamous squealing belt 200 miles from now, due to minimizing belt friction?

There's nothing cooler than having sports car and to pull up to places with a rattle. How embarrassing.

Any ideas would be helpful, or small tests or trials. I'm planning on driving it to the local shop 8 miles away for them to find the unicorn making all of the noise.

robthewrench · 03-17-2016, 12:05 PM

Is the rattle engine speed related? When you rev up the engine slightly does the noise also increase in frequency of rattles? Does the noise go away after the engine is warm?

Do not spray WD-40 or any other lubricant on your belts. This will only cause other issues.

If you are ambitious, you can remove the serpentine belt and then start and run the engine for a short amount of time. This would help determine if the noise is in any of the accessory drive system.

A different option is to get a 3 foot piece of hose and use it as a stethescope. Put one end to your ear and move the other end around the engine compartment to find where the noise is the loudest.

hankcah · 03-17-2016, 01:03 PM

I didn't pay attention to the engine while revving. But when I drive or get into 2nd gear you don't notice it / it doesn't amplify the noise.

While at red lights it will be silent for a minute and then noticeable the next. Doesn't change noise when I press/depress clutch pedal.

Yeah I'd be ambitious if I had a personal garage but when I did last year I remember being able to take out the fan shroud but not being able to get it back in, when I had a squealing belt.

I ended up dropping it off at the shop this morning. Fingers crossed that it's nothing more than a failing bearing on a pulley. If my car were human I would've dumped her over all of the small annoying problems.

Thanks for the reply and suggestions. I'm sure I'll be in the same spot again in the future.

03-16-2016, 07:55 PM	#1
hankcah First Lieutenant 43 Rep 364 Posts Drives: BMW 335i E90 Join Date: Jun 2010 Location: Saint Louis iTrader: (0) Garage List 2007 335i [0.00]	Rattling from front of engine, but does NOT rattle when I turn. I have a rattle noise that was intermittent, but now happens on startup. Happens regardless of the Heat or A/C on/off. It was rattling while I was pulling into the garage space, BUT it goes away slightly when I turn the wheel. My first thought was the power steering pulley. I think I had this replaced this past year, but not ruling it out. Had waterpump/thermostat replaced recently and had a hose disconnect, leaving me stranded. Would this have boiled the pulley or worn it down?? Could it be the cooling fan? Would you spray some WD-40 on the pulleys, or would this lead to an infamous squealing belt 200 miles from now, due to minimizing belt friction? There's nothing cooler than having sports car and to pull up to places with a rattle. How embarrassing. Any ideas would be helpful, or small tests or trials. I'm planning on driving it to the local shop 8 miles away for them to find the unicorn making all of the noise. Last edited by hankcah; 03-16-2016 at 10:30 PM..
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03-17-2016, 12:05 PM	#2
robthewrench Captain 266 Rep 952 Posts Drives: 11 E90 335i Join Date: Aug 2014 Location: Columbus OH iTrader: (0)	Is the rattle engine speed related? When you rev up the engine slightly does the noise also increase in frequency of rattles? Does the noise go away after the engine is warm? Do not spray WD-40 or any other lubricant on your belts. This will only cause other issues. If you are ambitious, you can remove the serpentine belt and then start and run the engine for a short amount of time. This would help determine if the noise is in any of the accessory drive system. A different option is to get a 3 foot piece of hose and use it as a stethescope. Put one end to your ear and move the other end around the engine compartment to find where the noise is the loudest. __________________ bone stock
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03-17-2016, 01:03 PM	#3
hankcah First Lieutenant 43 Rep 364 Posts Drives: BMW 335i E90 Join Date: Jun 2010 Location: Saint Louis iTrader: (0) Garage List 2007 335i [0.00]	I didn't pay attention to the engine while revving. But when I drive or get into 2nd gear you don't notice it / it doesn't amplify the noise. While at red lights it will be silent for a minute and then noticeable the next. Doesn't change noise when I press/depress clutch pedal. Yeah I'd be ambitious if I had a personal garage but when I did last year I remember being able to take out the fan shroud but not being able to get it back in, when I had a squealing belt. I ended up dropping it off at the shop this morning. Fingers crossed that it's nothing more than a failing bearing on a pulley. If my car were human I would've dumped her over all of the small annoying problems. Thanks for the reply and suggestions. I'm sure I'll be in the same spot again in the future.
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