Bought a car with rod knock unknowingly


I’ll just say this up front, I did a stupid thing and I’m fully aware. If you must comment about how dumb I am at least do it in a funny way.

That out of the way the car is a 2006 Chrysler 300 with 52k miles and the infamous 2.7L engine. Guy told me it had some lifter issues which is apparently very common for these engines. On inspection it sounds like it does. It also sounds like it has rod knock. I’m like 95% sure. I’ll be dropping the oil pan to verify this weekend.

My understanding is at this point is the car needs a new engine due to rod knock. I’m sort of at a loss now. I don’t have the space or skills to drop in a new engine. I never intended to keep the car. What’s the best way to get rid of this thing? It has 20" replica hellcat rims and tires which are like 95% new. There’s a bit of curb rash on the passenger side. I also have the original wheels and tires.

So you guys got any suggestions? I’ve heard I can throw new bearings in if the damage isn’t too bad, but that’s obviously not a fix. I wouldn’t resell it as is to anyone without informing them. Would it be worth anything “fixed”? Should I pay someone to drop in a new engine and resell it that way? I’m currently about $3k invested.


Best suggestion I can think of would be to take a potential loss and sell it as is, including what you know in the listing. If you never intended to keep the car, its really not worth the investment to get a new engine put in because you aren’t going to recoup that cost.


Hey Jordan,

Sorry about your misfortune. I wouldn’t suggest replacing the motor unless you are going to keep the car, because you will have a super hard time recouping that investment.

Secondly, I see you are 95% positive the issue is rod knocking. Are you possibly over estimating your certainty here. I’ve heard that there are some more minor issues that can sound like rod knock to the less trained, like carbon on a piston which is more common the older the vehicle. Are you a mechanic or particularly talented around cars. Just saying you wouldn’t want to trash your investment based on a misdiagnosis.

If all is doomed, I would suggest putting it up on craigslist and getting what you can out of the vehicle. I find it surprising how well vehicles sell on that site.


Exhaust manifold leaks, and exhaust shielding rattling can also sound like rod knock.

Does the sound come from the top of the engine or the bottom?


Bring it to DMS and get 2nd, 3rd, 4th, etc opinion on it. :smiley:


How much you think a new engine would be? If I could sell it for anything less than a $3k loss then that’s a win in my mind. So if total I spend 7k but sell for 5k then I’m only losing 2k as opposed to 3k.


Be careful of the sunk cost fallacy.

Your example is exactly that. Putting in $4K to possibly save $1K is just not worth it. You can probably get $1K or $2K for an OK looking car that drives with know possible motor issues. There you only lose $2K or less while not having to invest another $4K. If your going to give up on the vehicle, sell it. It isn’t valuable enough to do the repairs.

Just look at the KBB, even an excellent version is only $5K. Just not worth the repairs.


IMO, ID the problem without any doubts first.
Then move on from there.

Not to Nick but to @jordansal


I would be hesitant with this advice. A lot of times fully diagnosing a problem with a vehicle can be very expensive. That is why mechanics will often do smaller cheaper fixes hoping that they will solve or prove the issue rather than large disassembling to prove the core cause.

We are walking the line between cost and return. Also, the car may be more valuable without the definitive answer.


My car still drive and looks good, but it may be having some engine issues.


My Car looks good, but the engine is wrecked and needs to be replaced.

Which one of those two options would you pay more for?


Neither. I’d walk away really quick, unless the purchase price had the price of a “new” engine to be swapped in discounted and then some.


Tough to say. I didn’t have anyone with me yesterday and it’s only obvious when hitting the gas. At idle I can hear an occasional rattle or knock. Here’s a couple videos I took. You can hear the lifter tick as well as the knock. If you listen closely you can hear the occasional knock at idle as well.


I do my own work on my car, but outside of that no professional mechanic experience or education. I do webdev for a living so I’d say it’s a definite possibility I’m wrong here. I posted a couple videos below for you to listen to if you wanna hear the noise.


I’d love to, but I’m afraid to drive it that far. Don’t wanna cause anymore issues.


A bad motor mount might also sound like that. What happens when you rev it?

Might want to look at this thread, too:


I am NOT a car repair guy.

I did sell a car with a disclosed blown head gasket on CL.One buyer was interested and bought If it to learn how to replace blown head gaskets. Only person that contacted me too.

The optics on that repair was worse. Quoted price was $2,400. In the right light and a semi blind buyer that car was worth $3,000. Putting $2,400 into a “$3,000” value car made no sense at all.


I did not want to be reminded of that whole affair, which ended in an ultimately unnecessary firesale :frowning_face:


Should’ve been two videos. Here’s the second of me revving it.