Rattle at Startup

[g_128570]

too much valve clearance can cause a noise before oil is fully circulating. Does it do it every time engine is started or only after it sits for more than an hour or so?

It only does it after car sits for about a hour plus

 

[MrSimpleClarity]

What a cliffhanger!

So I've read this entire thread and had the same experiences of initial rattle.

After the first few years, I've always done my own oil changes on my original model 2009 Genesis Sedan 3.8, usually with Mobil 1 5W 20 and Mobil 1 filter. Never especially observed the filter, but wanted to try the dealer filters after this thread (cheaper than an engine, since I'm way out of warranty).

Can anyone please confirm that switching back to the OEM filter has stopped this rattle from occuring and kept it off?

 

[MrSimpleClarity]

I know this is an ancient thread. I've been lurking this site for years. If anyone is out there, thank you for helping me!

 

[PMCErnie]

Could be a faulty idler pulley.

 

[MrSimpleClarity]

It only happens for a few seconds at startup... wouldn't the idling pulley have more to do with idling?

 

[Gunkk]

A bad idler pulley bearing will sound more like a supercharger whine (pitch variable with RPM). Kinda sounds like a power steering pump w/ low fluid at idle, but rises in pitch pretty quickly like a supercharger.

Definitely keep to the OEM oil filters. I've seen enough horror stories from folks trying to save the literal $1 per year and doing Bad_Things(TM) to their cars.

Upping the oil viscosity one notch (to 5w30 full synth like Mobil1) has helped a lot of folks with noisy valvetrains. Just don't beat on it when cold .

 

[MrSimpleClarity]

Very helpful. I'll check it out. Thank you for the replies!

 

[Jatu]

too much valve clearance can cause a noise before oil is fully circulating. Does it do it every time engine is started or only after it sits for more than an hour or so?

Mine does it only on cold start up or after it sits for some time

 

[Jatu]

Noise at Startup - Sounds Like Timing Chain

OK - I promised an update, so here it is...
Dealership changed oil to Amsoil (their recommendation) and new filter. The noise improved slightly - but only briefly. It has come back and is now probably a bit worse than before. (about 3,000 miles since the change)
I've crawled around and listened and I strongly believe that it is the timing chain or guides. Looking at the engine breakdown, I see a pair of hydraulic timing chain tensioners that utilize relatively light springs that hold them in place (when there is no oil pressure) At startup, it takes a few seconds for oil pressure to build up - and during that time, there is probably sufficient slack in the timing chain, that it is making the noise. When the tensioners finally 'pressure-up', the chain rides on the tensioner guides and gets quiet.
The noise seems to be coming from the front cover - so this all makes sense to me.
At this time, we're waiting to hear from the district rep - who is supposed to come to town and listen to my car. Again, I'll post up as I find out more

 

[rmod]

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[BigSarge]

I've had my 2012 3.8 sedan for 6 years, bought used, has always made this sound at start up and still does LOLOLOL Runs great (130,000 miles) still reaches 130 mph easily.