Cold start rattle, timing chain tensioner

[mikewv1001]

I bought my 2011 genesis sedan with 3.8. Bought it with 90,000 miles, started rattling at 120,000. I have 180,000 miles on it now. Still making same noise. I have talked to 3 different service managers, they all have said that they are unaware of a timing chain failure in this car. Has anyone had an engine failure caused by the failure of the tensioner?

 

[Ozy44]

If you have noise that sounds like it's coming from the timing cover area, you will need to pull the cover to inspect the chain, guides and tensioner. I would first exhaust all efforts to find an external component that could be making the noise. Water pump, alternator, A/C compressor etc.. Try taking the serpentine belt off and running the engine on a cold start-up to eliminate any noise from the accessories. There are a pair of chain guides, one on each side, at the top of the chain between the cams. If they are worn this could be what you are hearing if the noise is in the upper chain area.

 

[mikewv1001]

I have had my car to 2 different Hyundai Dealerships. Both service managers told me the problem was with the timing chain tensioner. I am questioning their statement that this will not lead to an engine failure. If not, I can live with 5 seconds of rattling every morning.

 

[Easy]

Mikewv1001 Your tensioner makes sense since it's only at start up and last such a short amount of time. Taking off the serpentine belt and then coming back in the morning for a cold start is also a solid idea.

If it were me I wouldn't restrict myself to a Dealers opinion. Maybe check with an independent shop or two.

Pistons can slap like that as well during a cold start, and just for a hot-second.

First post here so if I missed the intro page, apologies.

 

[RemyBluePearl]

I’m at 77,600K 2012 3.8L and just recently I’m hearing a noise kind of like a grinding or whining I’d say so at first I thought it was the alternator but I went to my mechanic and he said it could be the pulleys which would be hundreds or if it is inside it could be thousands? Does that seem reasonable? I’m going back Saturday so he can take a look and hoping the noise is externally

Mikewv1001 Your tensioner makes sense since it's only at start up and last such a short amount of time. Taking off the serpentine belt and then coming back in the morning for a cold start is also a solid idea.

If it were me I wouldn't restrict myself to a Dealers opinion. Maybe check with an independent shop or two.

Pistons can slap like that as well during a cold start, and just for a hot-second.

First post here so if I missed the intro page, apologies.

 

[Ozy44]

I’m at 77,600K 2012 3.8L and just recently I’m hearing a noise kind of like a grinding or whining I’d say so at first I thought it was the alternator but I went to my mechanic and he said it could be the pulleys which would be hundreds or if it is inside it could be thousands? Does that seem reasonable? I’m going back Saturday so he can take a look and hoping the noise is externally

My 2012 3.8L had an idler pulley replaced at 68,201 miles due to a whining noise. The bearings had gone bad in the pulley. Part# 25286-3C250 was replaced and it eliminated the noise. Very easy job if you have ever replaced a serpentine belt, you can handle it yourself.

 

[Easy]

I’m at 77,600K 2012 3.8L and just recently I’m hearing a noise kind of like a grinding or whining I’d say so at first I thought it was the alternator but I went to my mechanic and he said it could be the pulleys which would be hundreds or if it is inside it could be thousands? Does that seem reasonable? I’m going back Saturday so he can take a look and hoping the noise is externally

Reasonable cost projection? Maybe.
Whether it's you or your fav mechanic, it's still a process of elimination. Does it sound like it's coming from right at the front of the engine AND external?
If so, he or you need to remove that Serpentine belt. And I'd remove it even if I suspected it was internal just to be safe. Plus, eliminating the natural noises associated with that drive belt and pulleys will further help you focus on the noise itself.

After belt removal, Noise gone? If so, now you simply rotate the differing pulleys and figure which *feels* rough provided it isn't easy to hear the noise spinning by hand. & etc.

Hope that helps.
E

 

[RemyBluePearl]

My 2012 3.8L had an idler pulley replaced at 68,201 miles due to a whining noise. The bearings had gone bad in the pulley. Part# 25286-3C250 was replaced and it eliminated the noise. Very easy job if you have ever replaced a serpentine belt, you can handle it yourself.

Reasonable cost projection? Maybe.
Whether it's you or your fav mechanic, it's still a process of elimination. Does it sound like it's coming from right at the front of the engine AND external?
If so, he or you need to remove that Serpentine belt. And I'd remove it even if I suspected it was internal just to be safe. Plus, eliminating the natural noises associated with that drive belt and pulleys will further help you focus on the noise itself.

After belt removal, Noise gone? If so, now you simply rotate the differing pulleys and figure which *feels* rough provided it isn't easy to hear the noise spinning by hand. & etc.

Hope that helps.
E

It does sound external and in front of the engine. With Ozy saying he had to change out the idle pulley it could be that since I did start hearing it at idle (coincidence maybe) but I’ll take your advice as well still have to do trial and error so you both have been a big help Thanks!

 

[PhorenReign]

Bump. My 2011 Genny is in the shop now for this grinding sound. Its become a lot louder over the months and I feel like the car doest accelerate well anymore. Anyway repair for guide a cvvt replacement is already at 5K waiting on an inspector to come take a look.. If they find metal shavings then the engine may be replaced. Did you get the issue resolved ?

 

[carguy75]

I have had my car to 2 different Hyundai Dealerships. Both service managers told me the problem was with the timing chain tensioner. I am questioning their statement that this will not lead to an engine failure. If not, I can live with 5 seconds of rattling every morning.

I would not follow that advice. If the timing guides are broken the chain could skip some teeth and cause some serious internal damage. However, it may take awhile for the issue to become that serious or it may happen out of the blue in the next couple weeks if the timing is thrown off too much.

I would either fix the problem soon or trade the car in as soon as possible before the rattling become more noticeable while driving.

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[RemyBluePearl]

Bump. My 2011 Genny is in the shop now for this grinding sound. Its become a lot louder over the months and I feel like the car doest accelerate well anymore. Anyway repair for guide a cvvt replacement is already at 5K waiting on an inspector to come take a look.. If they find metal shavings then the engine may be replaced. Did you get the issue resolved ?

If your asking me then yes I got it resolved and it was my idler pulley which cost me $220 at my mechanic.

 

[PhorenReign]

If your asking me then yes I got it resolved and it was my idler pulley which cost me $220 at my mechanic.

Remy did yo experience any acceleration issues? Slipping of any sort?

 

[DSXMachina]

Remy did yo experience any acceleration issues? Slipping of any sort?

An idler pulley just allows a belt to turn a corner. Worst thing that happens with a catastrophic idler failure is that the idler pulley wobbles so much that the serp belt comes loose. That of course can lead to other serious problems but that takes a while. Meanwhile you have all sorts of lights flashing at you on the dashboard. An idler pulley problem will not affect engine performance in any way -until the belt comes off the pulley. Then you are done driving for the day.

 

[Easy]

Also to add, part of the confusion was definition of *Idler* earlier in the thread.

Idler in this sense is; it does nothing, much like a person at idle.
It is an extra pulley positioned to allow the serpentine belt to align with the other items on the front of the cars engine that do *do* something. E.G., alternator, A/C compressor, Power steering pump and so on. Without the idler pulley it might be impossible or difficult to make the transition from one to another of the *work* pulleys. Idlers do sometimes get used as a tensioner for the belt. But usually those are called a tensioner pulley.

When remy replied to my comment ( April 30th) I didn't come back in and make a distinction; car idling/hearing the noise at engine idle. The only correlation there would be the engine is typically quieter at idle making a noise easier to hear.

 

[Rodraid]

Hi,

Reviving this, I used to be around this forum 10 years ago but have not stopped by in a long, long time. I still have my 2011 3.8 sedan, it has been a great car for me. A little over 157,000 miles without any issues. I didn't see the exact thread on this start-up noise I posted in many years ago but my car continues to make that awful noise on cold start-ups. I really could care less about it with the caveat it isn't doing real harm. Some mornings it seems to go on forever and sounds just horrible.

So my question is, has anyone had engine failure they contribute to this? If no I'm happy.

Thanks,
Rod