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Sonata Rough idle no power

looking for some advice. I’m looking to sell my 2009 sonata soon. I had an engine light and saw p0017 a couple weeks ago, accompanied by a tapping noise from the engine that speeds up as the engine does. On Friday I figured I’d take it for an oil change before getting a price on it from carmax, but didn’t wanna bother spending a lot to fix whatever was causing the code/noise. My Last oil change was August 2015, 6k miles ago. Jiffy lube said the oil was low and clearly it had been a long time since I had a change (time, yes, but not so many miles, but guilty I guess) so they recommended an engine flush. I said ok. Drove the car home from them and all seemed fine. Went to drive it Saturday night and it shakes and the lights flicker and I didn’t seem to get any power, I was afraid to drive it and wasn’t even sure I’d get enough power. My battery does this weird thing sometimes where it’s almost dead in the morning (no lights on and no parasitic draw, I’ve checked) and if I try a few times to start, with each try it gets better until it starts. So I charged it with a trickle charger and tried again but same problem. After this started it was also giving me a p0035 and p0135. I had it towed to a mechanic and they said something big time busted with the motor and it needs to be replaced. He said he didn’t even pull it into the garage, he just did something in the lot. I’m just looking to get it into good enough shape for carmax to give me more than a hundred bucks. I just decided to see if I could hobble it to another mechanic for a second opinion. It’s still doing the same thing, and if I let it idle the engine dies after maybe 10 or 15 seconds, but if I gas it right away it doesn’t Rev up fast but eventually does get up there and then it runs mostly ok, albeit noisier, now with a lower pitch noise accompanying the tap. The p0135 and p0035 are gone but now I still see the p0017 along with a p0170. I know this isn’t much to go on, but any thoughts? Am I actually screwed or could it be something else? Maybe a bad alternator or battery or spark plug? Something that could have been fouled up by the engine flush?

You are screwed. The combination of the two codes is not a good sign. I believe the P0170 is really a result of P0017 and that is not a good sign. For the ease of typing I just copy and past here potential causes:

  • Timing chain stretched, or timing belt skipped a tooth due to wear
  • Misalignment of timing belt/chain
  • Tone ring on crankshaft slipped/broken
  • Tone ring on camshaft slipped/broken
  • Bad crank sensor
  • Bad cam sensor
  • Damaged wiring to crank/cam sensor
  • Timing belt/chain tensioner damaged
  • An improperly torqued crankshaft balancer
  • A mis-built or mis-timed engine
  • A loose or missing crankshaft balancer bolt
  • The CMP actuator solenoid stuck open
  • The CMP actuator stuck in a position other than 0 degrees

I don’t think you get $100 bucks from Carmax

I’ll try to be a bit more diplomatic than the previous responder, but I do have to be blunt.

Going 12 months between oil changes is a very bad thing, and that is despite the fact that few miles were accumulated during that period of time.
Failing to check your oil (and replenish it as needed) every few weeks is potentially a very bad thing.
Engine flushes–especially if they are done by people with no mechanical skills–can damage an engine. Please note that few–if any–of the people at Jiffy Lube and their clones have actual mechanical expertise.

I suspect that this car’s engine has been a victim of poor/lax maintenance for more than just the past year, and now the chickens are coming home to roost–so to speak.
From afar, nobody can tell you exactly what the actual cause of the current problem is, but I suspect that the timing chain was damaged as a result of (pick one or more):

Low oil level
Oil sludge that resulted from that 12 month oil change schedule
The engine flush itself.

Of course that possibility is based on whether the engine has a timing chain. If it actually has a timing belt, then that leads to the next question:
Has the timing belt been changed? Based on elapsed time, it is either due, or is overdue.
Whether the engine has a timing belt or a timing chain, the problem could be due to valve timing that is “off” as a result of a stretched timing chain or a bad timing belt.
However, that is just a guess from afar.

What can the OP tell us about the car’s maintenance history?
Does it have a timing chain or a timing belt?

I think that’s what the mechanic was telling the OP when he said “…something big time busted with the motor…” I think that is the technical term for the more detailed explanation you gave.

Absolutely I have not been maintaining the car properly. As my first car, I’ve been a dumbass. Learned my lesson and will be keeping to proper maintenance schedules going forward.

That being said, the second shop that I took it to last night just called me, they said its the timing chain and recommended a new motor as well. Since they know I’m just looking to sell it, they said I’m better off just selling it for whatever I can get as is.

Googling tells me that a timing chain replacement costs $500-$1500. Why wouldn’t they recommend that? In better shape it should be worth closer to $3500, so I’d think it would be worth putting some money into. Is replacing a timing chain not actually that cheap? Or did it likely break other things in the motor?

If the timing chain slipped or broke, it is very likely that there was damage to the engine’s valves, and possibly to pistons.
If that is that case, that entails totally disassembling the engine for repair.
Between parts and labor, you would likely be looking at a bill of…maybe…$1,500, over and above the cost of simply replacing the timing chain.
If the car has been as badly maintained as you imply, I seriously doubt if this 7 year old car is worth the “investment” of a few thousand dollars, especially since the next thing to go will probably be the transmission.

Just a thought for the future:
Timely maintenance is invariably cheaper than the cost of the repairs that result from bad maintenance.

In my opinion you have 3 choices:

  1. sell the car “as is” and do let people know what is wrong. Some might be low on funds, but have the talent to do some work themselves.
  2. Get ONLY the timing chain fixed, probably tops $500 and hope that it puts the car in good enough condition to sell it for a little more than what you would get for now.
  3. Take the dive and spend the money, then sell it, but I am not sure how much you will get for it.

I don’t know if you could donate the car and take a tax break.

Take it as an expensive learning experience