Gas mileage suddenly got worse. – Submit Your Question HERE – Ask Scotty Community (carkiller.com)
Here´s a link to my previous question.
Bought this ´04 Elantra from a used car lot 3 years ago. Last oil change was October 2021 and we then moved states. Turns out my old mechanic put the wrong oil in this car. No lights on the dash, but car runs poorly. The garage where I took it says there is no point in putting a junkyard engine in a 19 year old Hyundai. Guess we´re done with this Elantra, then.
Should I buy my daughter a new car?
What kind of oil was put in the car? It would have to be something really off the wall to destroy the engine. How did the garage determine that the engine is shot? Is the engine knocking? Sludged up inside? Did they do a compression and/or leakdown test? Did they check it for codes and live data to see if maybe it's an O2 sensor or fuel injection problem?
If the engine is worn out it is not worth putting any more money into that car, but I'd want to know for certain that the problem is really that serious.
They found out 5W-50 was used during the oil change. Scan tool shows no serious codes. The Elantra just clatters on idle like mad. No, engine knock is not present. Compression was bad and they changed all spark plugs.
If it's clattering at idle (probably low oil pressure or worn valvetrain) and has low compression then yeah, it's done. Don't put any money into it. Time now to look for a replacement vehicle.
They found out 5W-50 was used during the oil change.
I wonder how they managed that. What oil is recommended for your car?
They utilized a rotary viscometer. 5W-30 should be used.