My 2014 Hyundai Tucson the engine got stuck, the engine oil get muddy and the car stopped and doesn't start. I removed the engine belt and try to turn the engine by turning the crankshaft with 22 mm spanner and nothing happen.

Please I would like to know if there is any sensor that stops the engine to protect them or I will have to take the engine out and do a complete repair?

  • I'm not convinced a regular 22 mm spanner by itself will provide enough leverage to turn the engine over by hand. Try increasing the amount of leverage before declaring the engine kaput
    – Zaid
    May 24, 2017 at 15:10

2 Answers 2


If there was a sensor to stop the engine, it would most likely cut the ignition to prevent it from running, not lock it from turning.

What you have described sounds like the engine was starved of lubrication resulting in bearing seizure, or worse. You will need to break it down to find the fault.

  • Or look at complete engine replacement. May 23, 2017 at 15:34
  • 1
    If you got really lucky, the problem might only be that the starter motor jammed when you tried to restart the engine. But if you can't turn the engine in either direction with a spanner, that is unlikely - especially if you try giving the starter motor casing a few thumps with a light hammer, and the engine still won't turn.
    – alephzero
    May 23, 2017 at 16:29

Muddy oil indicates coolant has gotten into the oil caused by a headgasket failure. Depending on the severity of the leak in the headgasket you may have either starved bearings and cylinder walls of lubrication, or had a lack of proper cooling- either of which could have caused a seized engine. It probably won't be cost effective to rebuild this engine if it won't rotate.

  • Headgasket failure is not the only way you can get a coolant in your engine. But overall I agree. This engine most likely will go in the bin. But for the sake of experiment we can pour some diesel into engine oil reservoir and see if it will dissolve the seizure. Mar 8, 2018 at 22:24

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