Connecting rod

I have a 2011 Kia Optima I went in for a routine oil change. a week later there was a noise a loud knocking noise and oil spilling from under my car I took it into the shop where I got the oil changed and they told me I thew the connecting rod in my engine… Is it possible the oil change has something to do with this problem?

It could be but that depends. The reasons for a thrown connecting rod are:
Metallurgical failure. (Odds almost zero)
Overrevving of the engine. (Not very likely or possible.)
Very high miles leading to excessive engine wear or wear due to extended oil change intervals.
Someone left the oil drain plug loose, the oil filter loose or double-gasketed, and the engine is out of or nearly out of engine oil.

The key question at this point is whether the drain plug and oil filter are where they should be; in place and secure.
If the shop screwed up the oil change they have a vested interest in covering their tracks and blaming it on something else.

Thank you so much for commenting…that’s exactly what I was thinking…that they tried to cover their tracks the car only has 63,000 miles on it and has been maintained properly they actually blamed it on a snow storm that we had before the oil change… they said I could have reved the engine too much and that I could have always had a leak


An engine with 63k miles should not be excessively worn with regular oil changes.

Was the car stuck in a snowbank and the engine excessively revved before the oil change?
Were there any noises at all during or shortly afterwards and before the oil change?
Is this facility a fast lube type business?

I don’t know what the specs are on the Kia but I’m sure it’s like most modern cars; it has a rev limiter designed into the ECU; or engine computer. If an attempt is made to overrev the engine the limiter will kick in and cause the engine to start cutting out.

Sorry I can’t be of much help without hands on the car but their mention of a leak at this point raises an eyebrow anyway. If there was a leak this should have been pointed out during the oil change; all assuming the leak is not a drain plug or oil filter.

Didn’t this car come with a 100k Powertrain Warranty?
If so, is the warranty still in effect?

I would have the car towed to a Kia dealership to see if they can confirm that the engine threw a rod.
If it did (as a result of something other than a low oil level), then the warranty should cover engine replacement.

OP: what you didn’t mention was:
Was the oil light on?
was the check engine light on?
did you check the oil level before the incident? After?
Did you have it towed to the shop? If yo drove it, then that was not a connecting rod issue.

“oil spilling from under my car”, that means the engine had some oil before the incident, so low oil was probably not the issue, assuming about a gallon of oil poured out.


a low oil light was not on… a check engine light was not on until after the noise started then the check engine light came on… I didn’t feel the need to check the oil before the incident because I just had an oil change. as soon as I heard the noise I pulled over I didn’t drive the car any longer it was towed to the dealer where I got a oil change.
@“Bill Russell”

If the oil change was performed at the dealership, and if the Powertrain Warranty is still in effect, I think that it would be very difficult for them to refuse to cover this under the terms of the warranty.

Has the OP phoned Kia at the corporate level, in order to discuss this situation?
The toll-free phone number can be found in your Owner’s Manual.

because I am the second one if the warranty is only covered at 60,000 miles, and I’m a 63,000 miles… the oil change was not done at a Kia dealership it was done at a dodge dealership where I bought the car… I am also taking a look at my oil changes in the past where the filter has a certain number repeatedly and now for the last oil change that I have gotten the filter has a different number what does this mean… could that mean the filter was not compatible with my car? @“Bill Russell” @VDCdriver


A different part number could merely indicate that a different brand of oil filter was used for the last oil change.

Even if it is the appropriate size/type of filter, different filter manufacturers will use different part numbers. So, this could have been a factor, or it may not have been a factor. From a distance–and without all of the parts numbers to compare–nobody can say for sure.

All of that being said, since this was a used car that you have only had for 3,000 miles, you are dealing with whatever abuse/neglect that car might have been subjected to by its previous owner(s) during the 60,000 mile period prior to your ownership.

I’ve actually owned the car for 12,000 miles and I’ve only had the oil changed by one dealership since I’ve had the car… I was saying the filter numbers match up except for this last oil change that I received. @VDCdriver @BillRussell

a woman wrote:
I didn’t feel the need to check the oil before the incident because I just had an oil change

Shops can make mistakes. Checking the oil after an oil change is a good idea that can save you some headaches.

It is rare for an engine to be running normally and suddenly with no warning throw a rod. All the thrown rods that I have seen resulted from the driver continuing to to drive despite hearing the loose rod tapping, as in Rod Knox. The term “Hot Rod” is almost certainly derived from the connecting rods tendency to fail when an engine is pushed beyond its designed limits. And when a rod is “thrown” it will usually blow out the pan or block and a great deal of oil will then leak out. A thrown rod is a very catastrophic failure. It would be rare that an engine with a thrown rod could be repaired. The freeze frame data from the check engine light might give an indication of the engine’s RPM at the moment of failure. That would be telling.

what are the numbers?

It could be a filter from a different manufacturer, different number, but intended for the same engine.


Even if the OP has owned the car for ~13K miles, the fact remains that whatever type of abuse/neglect the car was subjected to by the previous owner(s) could be the root cause of the current problem.

If oil changes were rarely done and/or if the car was driven in Severe Service conditions for the first 50K miles, it is very possible that the engine had lubrication issues that led to the rod problem.

Connecting rods break because of bearing seizure, and bearing seizure happens because of severe neglect and/or oil depletion. Sadly, it might be impossible for the OP to determine whether this seizure was due to this most recent oil change. I’m inclined to believe it likely was, but my inclination won’t help in court.

Because you’re the second owner, all bets are off. The “root cause” damage could have been there when you bought the car. All you can do now is to consider your options.

As so often happens here we are throwing guesses at the possible causes of a car owner’s situation with limited information. And as usual I begin to read between the lines and suppose the possible scenario that resulted in the thrown rod. Could this lady have been driving while dismissing the telltale knocking as just an insignificant rattle? Possibly she, or her husband or child or friend had become stuck in ice and found that holding the throttle wide open would result in successfully moving forward and eventually on their their way but doing so over stressed a connecting rod. Soon after that event, with a rod big end being loose on the crankshaft and hammering itself into oblivion and making a tapping that few of the public would recognize our OP finds herself facing a big problem and feeling certain that she has done nothing to cause the problem so she associates the last person who was actually under the hood with tools in their hands as a likely culprit.

It’s too cold here to bike or even walk today. Please excuse my efforts to deal with the boredom.

mountainbike, if the problem were due to the recent oil change, which implies the oil leaked out, would the oil light not have gone on? OP says it did not.

On second thought, I guess possibly the oil could have leaked out overnight when the car was not in use, then on first startup next day the rod broke immediately, thus the light never had a chance to go on. But is the rod breaking immediately a plausible scenerio? I would think the engine would run a few minutes at least, with the oil light on, before seizing.


PS, this is an interesting argument against remote starters, as you would not see the red light in time to shut down the engine.