Skip the auto shop - Our mechanics make house calls

Q: Engine rod knock

asked by on

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Quit running, but starts after waiting a while?

Hi There, What you are describing sounds like a common problem with ignition coils failing related to what is known as "heat cycling." Ignition coils are prone to this type of erratic functioning or heat cycling when they are beginning...

Q: Push starter making scratchy sound and starts after 2 tries.

Hi, thanks for writing in. This sounds like a different starter issue. A lot times when you have this situation, the starter has a bad spot in it and when it gets to that bad spot it is hard to...

Q: engine knocking

You are correct in that the knocking sound, depending on how severe it is may unfortunately be rod bearings that have failed. As you know, this is usually due to excessive wear or not enough oil lubricating the connecting rod...

Related articles

What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.