I was wondering today. I started my car, and the usual clatter was a bit louder.

From what I understand, direct injection means the engine makes a bit more noise than usual. But this time, it was different.. it was a bit louder, but it went away in seconds.

How can I reliably identify whether it's the cold start problem? I'd assume the noise the car would make would be very similar to a loud diesel truck. Am I correct?

 

You have the right idea. Definitely sounds like an old diesel. Direct injection noise is normal but the old diesel sound is a loud clatter. The DI sound is more dampened too and doesn't have the sharp sound the clatter does. It's also comparable to the sound an engine makes without any oil! Think metal to metal tapping.

 

Or a chain being dragged across hollow metal housing.

There are recordings/videos on YouTube of the phenomenon.

 

Now that's a better method of checking it out. Youtube is polluted with videos of the cold start chatter. ENJOY!

 

Thanks! I now have an idea about how cold start noises sound. Definitely not my problem - I suppose it's just the DI.

 

If, immediately after starting the vehicle, you hear yourself say loudly "Holy S***! What the f*** was that!!!", then I'd say you might have the problem.



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Then I definitely don't have the problem. It was more like "Damn, I didn't know Peterbilt built my car's engine!!!" :D

 

That is pretty close to what went through my mind the first time I heard it... LOL

 

yes, very loud m2m tapping, coming from the glovebox area. like a little toy snowblower. 20 secs to a couple minutes. no cels or codes thrown, car otherwise idles smooth. best not to drive until it goes away.

a lot of people think the DI is the cold start knock and it's not. The latter is its own unique beast.

OP if U can, park yr car nose down, let it go cold 6+ hours, and see if U can reproduce it. If so, take it in.
Dealers are much more aware of this now than say six months ago, and the tensioner check is pretty fast.

My car's going in to have the front clip repainted (botched dealer c/b job) so I hope it knocks for them, real loud, like it did for me twice--parked nose down both times, dead cold.

 

I always park my car nose down, so if anything goes wrong, I'll surely know soon enough.

DI sounds.. interesting. The clatter is a bit like an old car.

 

a group needs to be started to remove all those videos of shitty r56 problems

its bringing value/selling price down

 

This is likely the timing chain issue we've been seeing lately - the chain has too much slack and until fully warmed up slaps/drags against the cover. Make sure you describe it like this - loud grinding/dragging chain noise when first starting, cold starts; that should alert them to the SIB and get your car fixed - it'll take the better part of an entire day, too, so keep that in mind.

There are cases where the same concern above is just due to low oil - check the oil level yourself to confirm it's ok (not just for your own benefit, but to avoid having the dealer write your concern off to low oil level)