2007 Hyundai Sonata Intermittent code P0018

2007 HYUNDAI SONATA

30,000 MILES • 3.3L • 6 CYL • FWD • AUTOMATIC

APB520

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Vehicle with 30k miles (bought new and with regular oil changes) throwing p0018's intermittently. No noticeable difference in way the car drives: idling seems normal, fuel consumption regular, no power problems 0-50mph (I haven't taken it above 50 since the problem code first appeared.) There has been a slight engine tapping sound at low speeds only heard until the engine warms up after a couple of miles (I'm in Florida, temp is regular in the 70-80's), and the sound is not evident during the start-up, only while accelerating slowly.

Brought to dealer who, same day, requested doing an oil/filter change (I had done a change 900 miles/3 months prior) claiming that a wrong oil filter could cause blocked oil galleys. They did the change, repaired a valve cover leak and 6 days later called to tell me the car was fine. No mention of the car having been low on oil or evidence of sludging. Also, no mention of whether or not the filter that was replaced was the incorrect filter for the vehicle.

6 miles from the dealer after pickup (2 key turns) CEL returns, with same code. I have now driven the car about 160 miles in the last month with the CEl going off and on 6 times now, and each time the same code, p0018. The longest the CEL has stayed off was for a 30 mile span, typically returns after 10-15 miles. The CEl stays on for 3-6 key turns before going off. The tapping sound mentioned above continues too.

I've read up on the p0018 and it would seem that the initial dealership check using their GDS found nothing
except possible blocked oil galleys, hence the oil change. The p0018 could indicate a lot of different problems, but what could be causing only intermittent CEL p0018's (or intermittent CEL in general)? If the CEL stays on for an extended period again, I'll be returning to the dealer.

Apr 24, 2015 at 8:53 AM

ED-WEEZY21

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P0018 is a CVVT code right? Somewhere along the lines like a timing advanced or retarded? What does the actual code say?

Apr 24, 2015 at 2:43 PM

APB520

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p0018 is DTC for Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor A)

Yes, the CVVT might be involved. There's a TBS on it. Do you think the CVVT could be intermittently failing to operate properly, undetected by the GDS?

Apr 24, 2015 at 5:20 PM

ED-WEEZY21

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These are one of the more tougher codes to diagnose due to having multiple reasons to cause it. I had one of these same codes on a Santa Fe and chased it for awhile. My last step is how I figured it out. Under the GDS, I used current data to monitor and graph all 4 camshaft position sensors. The options to click are the camshaft actual positions and the desired positions. If there is any deviation between any of them (I used graph because I can easily compare the lines), then you have a problem with the CVVT on that camshaft and possibly the camshaft itself as well. The dealership should use this as diagnosis. If they find what I found, they need to inspect the affected camshaft and the CVVT for any signs of defects.

Apr 24, 2015 at 7:19 PM

ED-WEEZY21

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For example, there should be something that says Camshaft position "A" exhaust or intake actual position and under that would say Canshaft position "A" exhaust or intake desired position. Both of these choices are for the same camshaft and both should be almost identical. The desired position graph is going to stay constant and not change. If the actually position is bouncing up and down and looks nothing like it, there's your problem. Hope you figure this out.

Apr 24, 2015 at 7:26 PM

APB520

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Thank you. I'd been told something similar on another forum.
Still, the question remains: is it possible that what you've described (which seems to be due to a mechanical failure) can be happening intermittently and with no obvious symptoms except the CEL coming on? So, like right now the CEL is off, the dealer won't even put it on the GDS as there seems to be no problem.

Apr 24, 2015 at 7:38 PM

ED-WEEZY21

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I think that dealership is feeding you some BS. Just because the CEL isn't on right now doesn't mean that there isn't a code stored in memory. With the GDS, you can see how many times the code was triggered. So even if it is a history code when they scan it, but they see that it came on 5 or 6 times, that tells you right there that it will come back on eventually and won't just fix itself. And to answer your other question, yes it can be intermittent. It will see the fault and then set the light but then when the ECU runs its check again, it might not see the fault at that point in time and then shut the light off until it catches the defect again. The ECU will try to compensate the problem by either advancing the timing or retarding it. It will only set the light if after compensation doesn't work.

Apr 24, 2015 at 8:45 PM

APB520

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Thanks. Well, I can see the code p0018 stored in memory and how many times it's been triggered without going to them for the use of the GDS. And how it's always the same code. What I was told is that if I bring the car in to the dealership without the CEL on at the time, they won't handle it as if it was
an emergency problem, so wait until the light comes back on. If the problem isn't being triggered when the car is in the shop, what use is the GDS? This is what seemed to be the case when I first brought the car in, although they had it for 6 days. The problem doesn't seem to get triggered after the CEL reset (3-6 key turns) for 10-15 miles avg. Are you suggesting that the technicians should be able to see the ECU compensating in some way even when the CEL is off or even if the CEL is on but before the CEL reset occurs?

Apr 25, 2015 at 6:37 AM

ED-WEEZY21

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That's probably what they're getting at. They're claiming that they won't see anything while the check engine light is off. I can't say for certain that they will or will not see anything but they should've at least tried and had printouts showing what they did. If they don't show their work, and get taken to court, which happened quiet often with dealerships, they lose their case become there wasn't any proper documentation. Your best bet is to just drop in on them when the check engine light kicks on that way they can't turn you away because you're doing exactly what they're telling you to do. Sorry I can't be much more help. Seems like that dealership isn't trying very hard.

Apr 25, 2015 at 3:28 PM