Knock Three Times (Not a song)

[SixFootSix]

My 5.0 engine has developed a strange knock when it is first started. It only makes the knock 3-4 times, and then runs fine. The only time I have heard that type of knock before was on an engine with a bad connecting rod. I'm hoping it's only a temporary oiling issue. Has anyone else experienced this knock at startup?

 

[xiaphin]

Could be related to the oil consumption issue with these 2012 engines. Have you checked the oil level? I do not have any personal experience with this engine but there are a hand full of threads on the oil consumption issue for the 5.0. Many have been replaced under warranty.

Made me think of this song though...
Ariel Pink's Haunted Graffiti - Fright Night (Nevermore)

 

[SixFootSix]

Oil level is fine and I check it each week. I have not had ANY oil consumption issues in the past 5k miles that I have been driving. The car has 35k miles on it. The problem has now gone away (for the past two starts). Keeping fingers crossed.

 

[Mark_888]

My 5.0 engine has developed a strange knock when it is first started. It only makes the knock 3-4 times, and then runs fine. The only time I have heard that type of knock before was on an engine with a bad connecting rod. I'm hoping it's only a temporary oiling issue. Has anyone else experienced this knock at startup?

Can you provide the following:

• Model Year
• Trim Level
• Build Date (sticker in driver door jam)
• Bought new or used?
• What oil did you use at last change?

 

[84FordMan]

As long as it doesn't knock four times, you are good:

 

[SixFootSix]

2012 Utilimate, build Oct 2011, purchased used only 4K miles ago. Hyundai has performed all services. Oil is 10w30.

 

[Mark_888]

2012 Utilimate, build Oct 2011, purchased used only 4K miles ago. Hyundai has performed all services. Oil is 10w30.

I assume you have the either the 2012 V8 Technology Package, or 2012 R-Spec 5.0 (basically same features as Technology Package). There was no Ultimate in 2012, unless you have an Equus.

There were some problems with the early 2012 5.0 engines (Genesis and Equus). But the 4.6 was available in early 2012 model year, and that one had very few problems. One of the problems with the 5.0 seemed to be excess oil consumption, and Hyundai replaced a lot of engines because of that, and I would assume that along with the oil consumption problem, there may have been damage to internal engine parts.

If you car was CPO, you get the 10 year -100K mile warranty on the drive train. Otherwise I would consider getting a Hyundai Platinum Extended Warranty for about $1500.

I would also suggest you try a 5W-30 synthetic oil, or if you live in a very cold climate, try Mobil 1 0W-30.

 

[Gunkk]

If it was temporary on cold startup, then it's probably just a lifter. It's not an issue. The lifters are hydraulic and take a moment after a cold restart to refill with oil before they get pumped up, eliminating the tapping. Depending on cam position when the engine stops, a lifter might be stopped aligned with the oil supply hole, allowing the oil in the lifter to drain back. Many, many modern engines will do this and it's entirely normal.

Watch this video: https://www.youtube.com/watch?v=lorANZ1Tptw

If it's a big loud low pitch THUMP that you can feel, and not just a medium-pitch CLACK, then it's a bigger issue: oil not getting to one of the crankshaft bearings.

If the car was not purchased from a Hyundai dealer, I would recommend taking it in for an oil change, or DIY with the correct spec parts. Possible that the wrong kind of oil and/or filter was used which may contribute to the problem.

 

[SixFootSix]

Sorry, it is the 2012 5.0 with Tech Package. The nock is no longer heard, but it does seem to shudder a bit when accelerating. The idle is still just purring like a kitten, so it's a little confusing.

I will bring it to the dealer for an oil change, and before taking a 700 mile road trip.

 

[Mark_888]

Sorry, it is the 2012 5.0 with Tech Package. The nock is no longer heard, but it does seem to shudder a bit when accelerating. The idle is still just purring like a kitten, so it's a little confusing.

I will bring it to the dealer for an oil change, and a 700 mile road trip.

I would ask the dealer if you can bring your own oil, and then go to Walmart and get some Mobil 1 5W-30 in 5 quart jugs.

As mentioned, that particular engine has had problems, and many were replaced by Hyundai.

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[Doc W]

. . . it does seem to shudder a bit when accelerating. . .

If it knocks at startup and shudders under acceleration, it might just be a bad motor mount. Easy to check, and less catastrophic than a lube-related engine failure.

Doc

 

[SixFootSix]

Thank you for your insight on what might be the problem.

The dealer could find nothing wrong, and no engine codes that would indicate any problems. They replaced the oil filter, and replaced the oil with 5w-20 synthetic. The car is running just fine now, and ready for a long road trip.

It should be interesting to see if the thinner oil gets past the rings. It did not lose any oil in the past 5k miles of mixed driving.

 

[xiaphin]

Looking at some of the old threads I commented on and was wondering if your issue has gone away for good?

 

[MrWhite]

The first thing that I would do with this problem is to change gasoline. Sounds simple, but sometimes the simple things get overlooked.

Years ago, I developed a similar engine knock in my Isuzu. I switched from 87 octane gasoline to 92 octane and the knock has never come back.

Again, this may not be the problem. But it is very simple to rule out at your next fill up. If it doesn't fix the knock, you're only out a couple of bucks for the cost difference of the better gas.

 

[SixFootSix]

The knock at start-up can be heard only one out of every 6-8 starts. I truly believe it is one of the hydraulic lifters. The knock at start-up can occur after only a few minutes of the engine being off (i.e. At gas station, after fill-up).

The surging under acceleration went away after the car was recently serviced by the dealer.

 

[427435]

I would also recommend going to a 5w-30 synthetic oil. It's still a 30 weight oil at operating temp, but the 5w part will get the lifters pumped up quicker when starting.