2011 Sonata GLS, 133,XXX miles, 2.4L 4 Cyl.

I've only owned this car for a few months and it's been driving fine except for every once in a while the RPM's would drop to around 500-600 at idle for a second or two then go back to normal. I've only noticed the RPM drop maybe once every two weeks or so, and I drive it every day. One time the car loped after starting but when I turned it off and started again it was fine, and that has not happened again. Today driving to work I noticed an intermittent rattling/clicking noise coming from the engine when accelerating. On the drive home, the clicking noise suddenly became constant and the CEL came on. Code is p0011 'A' Camshaft Position Timing Over-Advanced Or System Performance Bank 1. Checked the oil and it was half a quart low, so I added oil. Other forums indicate one likely culprit is a bad Oil Control Valve (OCV). I removed the control valve on the front left side of the engine and it is not obstructed (stem moves freely), the resistance of the solenoid measures within spec (8.0 ohms), and when I apply 12 VDC the valve seems to be actuating properly (in both directions, depending on applied polarity). I removed and repeated the tests on the OCV on the rear-left of the engine, just to have something to compare to, and I got the same results. What concerns me the most now is the constant loud clicking noise coming from the top of the engine. Has the engine been damaged? Should I replace the OCV anyway even though it appears to test ok? I don't want to just waste money on parts (who does?). Could the problem be a cam position sensor? Is there a reliable way to test those?

I do not know the service history of the engine. I have only put 3,000 miles on the car since I bought it. Been averaging 31 MPG city and highway, so whatever has been going on has not been affecting fuel economy. I'm pretty good at troubleshooting and fixing everything attached to the engine, but when it comes to problems with the engine itself I don't have a lot of knowledge or experience. Any ideas of things to check would be very helpful.

EDIT: The knocking sound in the top of the engine sounds to me like insufficient lubrication in the overhead cam housing. So I just changed the oil this morning, but that made no difference. Any ideas?

 

Sometimes we can pin down the source of noises with a stethoscope and if that is not available, you use can use a piece of rubber hose to do the same thing.
You just must be very careful poking around an engine with a piece of hose when the engine is running. If possible try to see if you can determine where the noise appears loudest.

 

As far as I can tell, the noise is coming from the top of the engine.

 

That is still a bit vague. Maybe you can identify the cylinder and if it is on the exhaust side or the intake side. You can listen to the injectors and hear if they all make the same sound etc.

I have to admit this diagnostic matter takes some experience. Our '08 Sonata 2.4 also makes some ticking noise in the valve train. I believe some hydraulic valve lifters are clogged up.

 

*****UPDATE*****

This has been resolved. The problem was engine bearing failure. I thought it was a timing issue so when I dropped the oil pan to remove the timing cover and take a look, there were large quantities of metal shavings in the oil pan. At least two different types of metal. The engine is shot. I had it towed to my local Hyundai dealer. THE GOOD NEWS: Hyundai is going to replace the engine under a safety recall, so I got lucky there.

Thanks all, and regards!!

 

Yes! - We need to remember that there was a production error with certain engines. They did not clean the cylinder bores properly prior to assembling the engines. It appears yours was one of them.

 

The problem with those engines was junk rod bearings. Grit on the cylinder walls will cause ring damage not a spun rod bearing.