Ok, so hopefully "time bomb" is a little over the top....

My 2003 M3 has been happy as a clam without issue. Spent the night in the city parked on one of those famous SF hills (nose high, for those curious) and when i started the car next morning, the motor is making this rather obvious ticking sound (pretty loud actually). I confirm it increases with revs and then pop the hood to check for the fan or other areas contacting plastic shroud or other obvious culprits and find nothing.

With no obvious items contacting each other on the front of the engine, i listened to every area of the engine from the top to try and pinpoint, but alas it's loud enough under there that I could only say it appeared to be coming form the passenger side of the engine. With nothing left to do at that point, I drove away with this racket even worse at driving speeds...for about 2 blocks that is, when the noise disappeared!

Is it just me or is it possible that parking on the hill caused something loose in the motor to settle in the wrong place?

I recall finding my oil pump in the e34 dangling loose before and couldn't help but wonder what items are known for coming loose on the E46 M3 motor?

Any/all ideas appreciated.

 

If the noise goes away after you warm it up I would not be too worried about it. I'm sure parking it on the hill does not help, possibly starved of oil. I doubt it. If the sound continued and never stopped I would be concerned. If it does blow up I'll take your Dinan parts

 

Trust me, if you had heard how loud this metal/metal noise was while driving, you would be worried. While it is gone, it was clearly very bad for whatever surfaces were meeting each other. Ain't nuthin like a good mystery

 

I had the same exact noise on my 06 e46 m3. It ended up being the Vanos, thankfully bmw replaced it under warrantee or it would have cost over 10 grand.

 

what went wrong with vanos and what were symptoms.

thanks, BOSS

 

only thing that immediately pops into my head would be oil starvation because you were on the hill has the noise continued since? vanos could be at well depending on the mileage and how hard you drive the car...when was your last oil change? could be the oil is getting too dirty perhaps?

 

The old E34s were known for it as the bolts as you said, would back out. Causing no oil pressure.

The M3 oil pump is a two chamber design. The front chamber picks up oil at the front portion of the pan (which is baffled). And transfers oil to the rear main sump, where it is pumped in the main gallery.

I don't see oil starvation being a problem on a hill, unless you are quite low on oil.

If you want to avoid the stealer, go buy a cheap stethoscope and interrogate all the obvious areas at the top of the motor. Both sides, intake and exhaust of each cylinder (you may have to bend the heat shield a tiny bit, but it can be pushed back down). Check the vanos, A/C compressor etc.

How many miles on the car? Valve adjustment been done? I've seen people goof up the valve adjustment, grenading the head on the motor. But the car still ran for 15K+ miles with track days, and lots of 8100RPM action.

Retaining spring was installed incorrectly....

 

My guess is it was a vanos noise and the engine was oil starved...try parking it flat and see what happens.

 

how many miles are on your motor and car? those motors have always been noisey in the morning but you would know best as the owner if its a different sound. I'd say double check your oil level and try to park with the nose down and see if the noise comes back...? want to sell me the car for cheap??

 

Should have provided the obvious details... oil level is fine and this was a one time event during and overnight in the city. Short of lifting the nose of the car on jacks over night, I can't duplicate.

Car has 80K mi, has always been current on scheduled maint and has run like a champ. I've never noted the motor as being noisy, but then the Dinan exhaust is pretty much all you hear on startup each morning.

Worth noting this was a mild hill (perhaps 10% grade), so oil starvation to VANOS or anywhere else would be strange.

 

wow glad im not the only one... Mine happened when i was picking up a friend he lives on a very steep hill. only thing i recalled was scraping the front bumper alittle coming down the hill. Instantly while driving down I started to notice a metal clinging noise coming from the passenger/rear underneath.. at times the noise got really bad. after 15 minutes of driving the noise completely went away. I drove it really hard for the next few hours. everything seems fine... On a side note my suspension seems to be worn out audible hissing noise when i go over regular bumps.. maybe it has something to do with that?

 

Park the car level, let it warm up and check your oil level. My E36 M3 and friends E46 M3's every once in awhile would get the ticking nosie, it's a typical BMW noise and means you burned some oil and are a little bit low.

People often get it during AUTOX and such or on a skidpad when going repeadetly in one direction causing a little oil starvation.

 

Definitely oil starvation. Check the oil level on a flat surface. As long as it doesn't come back, you should be fine.

Nice to see you on here Cory, how's the lotus treating you?