Hi guys, recently bought myself a Hyundai sonata with 171k miles for a grand and it has all paperwork done from 30k miles onwards. It runs great and has 180k now but I recently noticed the engine making this noise while idle, is it normal or something to be concerned about? This is my first Hyundai so not sure if it's normal or not. Currently running Mobil 1 5w 30 full synthetic. I have scanned it with my tool, no errors.
Video link https://www.youtube.com/watch?v=RP1fVXTMw_A
It sounds like it may be the serpentine belt making noise with the idler pulley and the tensioner pulley. Do you know if the timing chain kit has ever been changed out?
You might be right, when I start it up in the morning it does squeal for a minute or so until it quiets down. Based on the records I have it doesn't appear the timing chain was ever changed. I see the MAP sensor, crankshaft position sensor and oil sending unit were replaced about 12k miles ago, 2k before I purchased it. Should I look into getting the idle tensioner, belt and then timing chain done?
The timing chain is about a $1500 proposition. If the engine rattles when started cold and the noise goes away in a second or two, it is definitely the timing chain. If not, probably not. I'd start with belts and pulleys, including the pulleys on the PS, alternator, water pump and ac compressor to isolate where the sound is coming from.
Oh wow, yeah that's quite expensive for the timing chain, I'd like to avoid that if at all possible! Sorry I wasn't clear in my last comment, but I can certainly hear the serpentine belt squealing/squeaking for the first two minutes or so of my drive on cold starts. I will start with getting all that done, thanks for the help1
If the timing chain is not making noise and there are no symptoms then there would be no need to install a new chain. A quick test is to check stability of ignition timing. Scotty shows doing that with a timing light in this video, but you can also use a scan tool that displays live data:
https://www.youtube.com/watch?v=3zyjyVUoe6c
I would have to take a look again but did check live data earlier and if I remember correctly it was all stable at 9 degree, could be off but I know whatever it was it wasn't fluctuating.
The video says "How to check a timing belt" but the guy is pointing at the timing chain. Huh?? @chucktobias. Is this an April Fools thing?
Scotty says that method can be used to check either for looseness, which makes sense, though with belts of course it's best to adhere to the recommended change interval. Properly designed timing chains will usually last the life of the engine if regular oil changes are performed.
Too bad that shaft drive used in some early overhead cam engines like Wills St. Claire in the 1920s and postwar Crosleys fell out of fashion - no chain or belt worries! You'd also never have head gasket problems on those engines. (Though I guess there you had to worry about gears and bearings wearing out in the camshaft's shaft drive.) Image below is cross-section of Wills St. Claire V8 engine:
