Rattle at Startup

[carpatcher]

2009 V6 Genesis Sedan, 36,000 miles
Recent development is a rattle under the hood, at startup. Only lasts for 3-4 seconds, but certainly has the sound of a loose timing chain / or lazy tensioner or something similar.
Took it to the dealer - who pronounced it 'normal' (grrrrr)
It's not.
He's now suggesting changing from the dealership oil (dino/syn blend 5W-20) to full synthetic. Specifically he's saying to go to Amsoil Signature 5W-30.
I'm inclinded to do it, as I'm still under warranty - and I'm thinking that IF I do all he instructs and the noise goes away; Fine. And, IF I do all he instructs and it's still making a racket, then the burden is on him.

I've read some threads on a similar noise - but have not found anyone who's actually resolved the problem - any help out there in G-land? Had this problem and found a real solution ???
much thanks.

 

[homeofstone]

Has anyone checked the valve lash? The 3.8 has adjustable valves that have to be serviced/adjusted to specs. (see manual page 7 - 8)

 

[carpatcher]

Thanks for the suggestion.
Excessive valve lash would probably not disappear in 3-5 seconds.
It would normally sound like a constant ticking or clicking sound, with the engine running.
In my case, after the initial noise, all is quiet and the engine runs and sounds very normal.

 

[homeofstone]

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?

 

[427435]

First, Amsoil is high priced snake oil. Your dealer will charge you dearly for it. On the other hand a good synthetic oil is a good idea. This link provides the oils that are approved for use in Corvettes and is a very rigorous spec.

http://ls1tuningguide.com/files/freefiles/gm_approved_engine_oils.pdf


Below is a link to the various Mobil 1 oils including which meet several tough European manufacturer specs.

http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf


Buy a case of your choice and take it to the dealer-------just make sure he uses it.

 

[TJPark01]

I used to get intermittent noise at start up. I switched to M1 0W-20 AFE, haven't heard it since. It's been about 9 months.

 

[carpatcher]

Thanks

Guys,
Much thanks for the input.
I'll go the full-synthetic route and will report back.

Scheduled for oil/filter next week....my oily fingers are crossed!

 

[carpatcher]

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.

 

[radicaltimes]

Mine has done it since new. The dealer said it was normal until the Hydraulic chain tensioners had oil pressure. It does not help that the oil filter is upside down on top of the motor.

 

[dkoelzer337]

My wife's IS250 used to do something very similar. Turns out there was a service bulletin for a "cam gear assembly". My 2002 VW 1.8T has made a similar noise at start up for years but the dealer has never been able to diagnose it.

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[carpatcher]

New Engine!

Well - I finally got the call.
The service manager has offered to install a new engine in the car!
(this is a v6)

The engine is at the dealership now (we waited for one to come over from Korea, according to the service manager) - and now are waiting on a few parts to be shipped in from the west coast.
The car should be in the shop within 10 days - and I"m hoping it will be running "like new"

I'll give an update, once it's back with new iron!

 

[ruggratt]

Why are they replacing the engine? Did they say what was wrong?

 

[carpatcher]

New Engine

Ruggratt,
The dealer has not been specific about what is wrong - I'll try to find that out next week, when we get scheduled in for the replacement.
Personally, I'm convinced (after listening to it with a stethoscope and hearing it from above, below and beside the engine over the past 6 months) that it is a problem with the tensioners or the chain ramps.
I think I"ll have them cut and inspect the oil filter carefully - I think the chain ramps are a high density FRP material - if so, some of that material might be visible in the filter.
If they are super-cooperative, I might ask them to pull the timing chain cover when they have the old engine out - we'll see how that goes!

 

[Geneva]

Initial rattle at startup is normal for 1-5 sec at startup depending on the Oil filter used. But seeing you take your car to the dealership, it sounds like possibly you have timing chain tensioner's that are bad, they are hydraulic and if the oil pressure has to build your hearing the chain hitting the guides and that will need to get the front cover pulled to replace the tensioners and guides.

 

[carpatcher]

Oil changes all done at the Hyundai dealer.
(his filter...his oil)
The noise started when the mileage was in the 30's.

I'll report in when I get the autopsy!

 

[carpatcher]

Rattle at Startup - Final Chapter!

Sorry for the long delay - I said I'd report in when this was settled and it now is.
The clatter or rattle at startup turned out to be a defective v6 engine. Dealer did a top-notch job: brought in the regional rep and they all listened and checked it out - rep said to replace it.
Upon removal of the old engine (42K miles) the mechanic pulled the pan and inspected it - and was nice enough to call me and I got to see it. Looks like there was excessive fore/aft play in the crank. He took a couple of screwdrivers and showed me that he could easily move the crank back and forth (like if the thrust bearings were worn out on an old GM block). The noise I was hearing was the crank/rods moving front-to-back at startup. Once oil pressure was up (3-5 seconds) it would quiet down.
They installed a brand new v6 - absolutely no charge to me. They did transfer some old parts to the new engine(alternator, plastic cover and some other pieces/parts) but everything else is new.
They also provided us a loaner for the time it took to do the repairs.
I'm saying Two Thumbs Up for the Medlin Hyundai guys.

After all was done - the defective engine was shipped to Hyundai Engineering, who (I am told) will do a tear-down and see what went wrong.
A happy ending for our Genesis.
Back on the road again....

 

[kf4zra]

wow, thats a lot of money they put into that car. Thank you for the update.

Did the guy that said it sounded normal have anything to say about Hyundai's solution?

 

[NSXNEXT]

Wow. Nice to see Hyundai step up.

 

[Vermillion3]

Did the guy that said it sounded normal have anything to say about Hyundai's solution?

Crow is a dish that the dealer rarely eats. Good for the OP though glad he was able to get his problem solved but again only through persistent asking for something to be done. To the point when the dealer does capitulate and address the previously labeled "NORMAL" noise; it is a great victory and vindication for the customer.

 

[carpatcher]

Well -in defense of the dealer, they did not stiff-arm me at all.
They did ask me to try a few things (synthetic oil, change of filter, inspection by service manager, then district rep, etc)
I did cooperate with all these requests and did make the car available to them when they asked (like when the rep was scheduled to be in town, and letting them keep the car overnight, so they could do a cold startup)

So - I think that being a 'good customer' pays (courtesy, polite responses, etc) - after all, I am the 2nd owner of this genny (not the original)
I think they've stepped up and done it right.

Here's the real proof: I'll buy another one!