Any ideas on this ?

[Khocquard]

So I purchased a 2010 E93 in the fall and got to drive for about a week before I put in storage. I live in Northern Michigan so it has been VERY cold. I start the car about once a week and let run for a while. I noticed a sound from the motor and was hoping someone could help. Below is a youtube clip (NOT MINE) but it sounds just like this. Start about 20 second mark.

[MaximusB]

You shouldn’t start the car every week. You’re much better off leaving it and only start it when you actually take it out of storage.

If your car does sound like that video then it is rod knock.

[Shiza]

It's hard to tell from a video but I'm not convinced that rod bearing failure. Click on users videos and check out the second video he has of the car while its warm. It sound more like an exhaust leak at the manifold.


The S65 makes a ton of loud and strange noises. I wouldn't write this off as rod bearing failure quite yet. Just to be safe I would tow it to a shop that is well versed in the S65 and have it diagnosed.


And much like Maximus said. Best practice is not starting the car while its cold and sitting if you're not going to drive it. Especially in such cold weather. It's much better for the car if you just leave it on a tender and sit until you're going to drive it.

[amrazM]

Originally Posted by MaximusB

You shouldn’t start the car every week. You’re much better off leaving it and only start it when you actually take it out of storage.

If your car does sound like that video then it is rod knock.

In agreement, leave it on a tender and only start it when you are going to drive it. Reason being the crankcase needs to reach 212*F to boil off any moisture inside.

Also there wasn’t any perceivable sound of knocking in that motor, just a lot of ticking which is fine that’s how these engines sound, maybe you guys are hearing something i can’t pick up

[Helmsman]

Sounds like mine so hopefully perfectly normal (btw I replaced shells).

[CSBM5]

I think what you're referring to is the rather radical noise the S65 makes during the time its cold start cycle is active. An electric air pump is activated injecting air into the exhaust headers, and what you're hearing during this time are the each of the cylinder's exhaust pulses -- the 'after' combustion burns in the exhaust header pipes exaggerate the noise transmitted. It always reminds me of the ancient days when installing thin tube headers on a car which always resulted in that ticking sound at slow engine speeds.

If you notice right as the air pump cycle completes (about 1:50 in that video), the "ticking" dramatically declines -- that is the air pump shutting down and that follow-on burn (loud ticking) in the headers going away.

You can tune out the air pump in the cold start cycle if you don't like it. All it does is help the cold cats light off slightly quicker.

If you pay attention to follow-on starts that aren't fully cold, you'll likely hear the cold start cycle for a much shorter period of time, sometimes just a few seconds. Also even when cold start isn't active, there is some typical tube header exhaust tick noise present as one would expect.

Rod bearing tick, unless it's majorly progressed, makes itself known more under load and low rpms usually (2000-2500). At least in the only experience I had with it on a small block a bazillion years ago, it was very evident under load and in that engine's case, easily caught in time. At idle it was not present (since loads are so small compared to when the engine is generating power and being put under load).

[bigjae1976]

I haven't driven my car for about 3 months, started it up and then I had a ticking noise. Of course...like any well informed E9X M3 owner I spazzed and then immediately searched the forum. I left the car running, went back out and the noise was gone.

Just needed to let the car fully warm up.

[commedeschatons]

all i hear is normal ticks, sounds OK to me

[Helmsman]

OP, any updates?