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(This is copied and pasted from my thread in another forum dedicated for this car make, didn’t receive much help so I am now coming to you guys)
Hello! I own a 2007 Sonata 2.4l GLS with 120,500miles on it. In the past three weeks (recently after oil change) its developed a clunking noise only when warmed up (about 40 seconds). I purchased this car beginning of August and it had no noise then. I changed the oil with 10w30 castrol hm oil (the dealer I bought it from stated they put in same viscosity although oil cap reads 5w20 manual says 5w20-10w30 depending on climate is acceptable) . I’ve had it checked out by mechanics who have no clue what it is and want to tear down the engine. The noise goes away if it revs a bit higher that 1500rpm and then cones back worse when revving down until idle where its not as bad again. I’ve changed sparkplugs (they were factory anyways) and ran premium fuel and even bought a Hyundai filter afterwards hoping it would help but to no avail. I have a video sound clip where its clearly audible http://www.youtube.com/watch?v=ZVSjxpsOspU&feature=youtu.be
Your help is greatly appreciated
UPDATE- I’ve tried running an oil thickner from STP which claims to cushion noisy valves and engine noise but it did not help at all, infact the noise became worse. Today I poured in a whole can of seafoam into the crankcase before I change my oil and filter again on Thursday, should I try running a 5w30 Mobil 1 synthetic and if noise goes away try the HM version of the same viscosity synthetic? I believe the HM oil may have cause some debris to either come loose and stick the valves or removed the debris that was cushioning the noise.
EDIT: Could it be the PCV valve or loose flexplate bolts? I ordered a PCV valve which comes in Tuesday i’ll be replacing that since it is a maintenance item. I don’t to check the flexplate if it doesn’t sound remotely close to being the issue since I’d have to go through the hassle of removing mudguard, lifting car and removing the inspection cover.
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Hmm, engine damage at that low mileage is not too likely unless you waited WAY too long to change oil. Yeah I done that before on a ford :blush: Luckily my tapping never got worse.
Is it possible something outside the engine like maybe a spark wire is deteriorated or loose? That is what it kind of sounds like but that would not explain why it takes about a minute to start happening.
I guess you can never know this but is it possible someone dumped snake oil in the engine before selling to hide that noise (temporarily)?
Hopefully Eric will chime in.
The snake oil was my dad’s and I first hunch, the shop (former rental) claimed that it was regular 10w30. I wish if it was some type of chemical he’d just tell me I wouldn’t mind if it made the noise go away. I hope Eric chimes in too, I’ll get a new sound clip tomorrow the sound may be a bit different now from what it shows in the video. Thanks for helping out Nightmare!
It does sound like engine trouble to me…Sounds like a bad lhydraulic lifter in the engine, hence the rhythmic tapping sound. This isn’t the end of the world, but would require going into the engine. Best of luck…
I am not familiar with those engines but yeah, lifters sounds possible.
If the lifters are overhead then messing with them might not be too much of a hassle. Even if NOT overhead lifers it won’t be horrible. May take a day or two to mess with though.
If you pay a mechanic to do that job, one lubricant he might use is called astro glide.
“What does that do?” Well it’s for… ehh don’t ask. AAANNNNYYYways, see what it would take to investigate bad lifters.To my knowledge, this is a solid hydraulic lifter. Therefore no valve adjustment is necessary. Some of the Import/ Hyundai folks may want to weigh in….
It’s never a good idea to go outside of what is recommended on the oil cap. This can often make any damage much worse. We talk about this in this video. Resist the temptation to install thicker oil. The difference between 5w20 and 10w30 is significant. Enough to cause issues. Adding oil thickener just makes things that much worse. Also, it sounds like you have a sizable exhaust leak as well.
I switched out the oil today I put in 5w30 Mobil 1 synthetic with a fram ultra filter,the noise became a bit less audible once all the seafoam and STP thickener drained out. Eric it states that 5w20-10w30 is good for the car depending on the temperature so I wasn’t out of spec. An exhaust leak does seem plausible since its gotten generally worse with time after the initial oil change that started the whole ticking. I might use a stethoscope around the exhaust area on the engine, thank you for all the suggestions guys!
unfortunately it sounds like your engine is starting to wear out. those Korean cars do not hold up well over long periods of time and yours is 7 years old. most people get rid of them before they reach 100k because that’s usually when they start to have problems. my advice is just live with the noise because it will cost thousands to rebuild that engine and the car is just not worth that much.
[quote=”07Sonata” post=113616]I switched out the oil today I put in 5w30 Mobil 1 synthetic with a fram ultra filter,the noise became a bit less audible once all the seafoam and STP thickener drained out. Eric it states that 5w20-10w30 is good for the car depending on the temperature so I wasn’t out of spec. An exhaust leak does seem plausible since its gotten generally worse with time after the initial oil change that started the whole ticking. I might use a stethoscope around the exhaust area on the engine, thank you for all the suggestions guys![/quote]
Any way you could post where it says that? Perhaps a pic of where it shows that in the manual? I ask this because many newer vehicles don’t use the temperature recommendations anymore. They usually only list one viscosity and that’s that. The only place I see temperature listings is on off road vehicles these days. Not saying you’re wrong, just trying to educate myself.
[quote=”EricTheCarGuy” post=113729]
Any way you could post where it says that? Perhaps a pic of where it shows that in the manual? I ask this because many newer vehicles don’t use the temperature recommendations anymore. They usually only list one viscosity and that’s that. The only place I see temperature listings is on off road vehicles these days. Not saying you’re wrong, just trying to educate myself.[/quote]I understand! I screenshotted the online manual for easiness sake, both online and paper are identical. If you would like to check it out yourself its A3KO-EU6ON. Its section 6 page four or page 215/283 in online version. I still haven’t gotten around to doing the sound clip the car’s situation is depressing, will upload tomorrow for sure.
Also the whole newer vehicles not displaying the ranges anymore, I read somewhere that this car was produced with old Hyundai thinking it wasn’t until the 2009 they started producing better Sonatas of the same generation.
Here is a new sound clip from today. http://youtu.be/M9gFC0hMQ1o
That exhaust leak sounds worse to me, the ticking about the same… Better get on that, as you don’t want carbon monoxide poisoning in the cabin… Hope you get all this sorted out.
I don’t think there’s an exhaust leak when listening in person its much smoother I believe its just my phone distorting the sound a bit.
I may try seafoaming the intake today see if that helps
Thanks for posting that information. I didn’t expect that but it’s nice to know they listed that for you. Not using the correct viscosity is one of the main causes of increased engine wear. That said, you might start by repairing that exhaust leak and then seeing what kind of noise you have after that.
If it is indeed an internal engine noise, the only way to find it for sure would be to tear the engine down and check the clearances.
Keep us posted.
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