Q: can the oil in my coolent reservoir be caused by a bad coil

asked by on May 25, 2017

I got a oil change and the mechanic said that the coolant reservoir had gunk in it .that I should maybe think about trading it in or take it to the dealer. then my engine light came on and I had the code check and it was coil 4 misfire. can this be the cuase

My car has 63000 miles.
My car has an automatic transmission.

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"Gunk" can simply mean that the coolant is old and in need of a cooling system flush.If it actually oil in the coolant reservoir, then odds are the head gasket may have failed. The head gasket keeps oil and coolant passages separate and allows oil and coolant to flow between the engine block and cylinder head. The misfire in cylinder #4 can be due to a bad coil or possibly the head gasket has failed around cylinder #4 and is causing the misfire. Something to consider: If you purchased the vehicle new, then your engine may still be covered under the Hyundai 10 year / 100,000 mile warranty. If the head gasket has failed, the repair may be at no charge to you.

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