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Q: Engine rod knock

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Trading my car at the dealership & they inspected my car & gave me the value. Next day before I go to trade in my car I turn my engine on and hear a loud rod knocking. Called the dealership and explained the problem. They said since they already inspected my car, to just bring it to them and they will repair the engine. But in order for me to get to the dealership they said to use a thick oil in the engine to temporarily stop the loud knocking. What's the best oil to use for my Chrysler 300 for the rod knock? And how many quarts do I need? Thanks in advance!!

My car has 89000 miles.

A: Hello and thank you for contacting YourMech...

Hello and thank you for contacting YourMechanic. The oil to use is a thick 15/40W oil for diesels. This oil is thicker than normal engine oil and can keep an engine from knocking for a little while. If the engine continues to knock after putting the oil in, I suggest not driving your vehicle to the dealership. If the dealership will take your vehicle in for trade, they will do anything to get your vehicle to them, even if it requires a tow. I recommend having a professional, preferably a professional from YourMechanic, to come to where you are and check out the knock in your engine.

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