Knock sound when turning car off
 

Occasionally, when I turn my car off, there's a knocking sound, fast at first and then 'winds down' until it goes away (probably 2-3 seconds). It sounds, and feels, like the engine is off.

I looked at this thread: https://www.crossfireforum.org/forum...ine-knock.html but didn't really find anything concrete.

Seems like it's only been doing it the past couple months, which I've replaced the ABS/ESP control modules, throttle body, and added a CAI. None of these seem like they would be the cause of the problem. I've changed the oil, using 0w-40 (8 quarts) and the correct WIX filter, but aside from that I have no idea what could be going on as I've not heard this in any of my other cars.

I'll try to get a sound file to post today or tomorrow, but until then, any ideas?

Re: Knock sound when turning car off
 

...Winding down......sounds like the fan is hitting something.

Re: Knock sound when turning car off
 

And it probably is. I had to replace the upper coolant hose because the fan slowing rubbed a hole in the side and made the hose blow. Have someone turn the car on and off for you with you looking under the hood maybe?

Re: Knock sound when turning car off
 

There is a recall or TSB on this.
Go to Chrysler.com > owners and enter your VIN to check if your car is part of the recall.

Re: Knock sound when turning car off
 

Are you sure it was not the fan shroud that was rubbing the hose, as there is a TSB on that issue. It seemed to occur on 2004 models, mine among them, and the fix is to turn the hose a little, which moves it away from the shroud.
I really can't see the fan hitting the hose when the engine has stopped because it would be too obvious and the hose would not last too long.
I would think that if some object was in the heating fan area it may hit the fan there and that has certainly occurred before.

Re: Knock sound when turning car off
 

the only noise I hear when cutting mine off is a knocking sound from the lifters oiling down on shutoff

Re: Knock sound when turning car off
 

do you have the six speed or the auto? because i have the same noise when turning the car off. i though it was the engine but when i push in the clutch and turn it off there is no knocking sound. maybe something in the transmission.

Re: Knock sound when turning car off
 

That is exactly what my car does??? I just posted it yesterday in the roadster sec. asking if anyone had a clue. No responses. im asking the dealer about it tomorrow.

Re: Knock sound when turning car off
 

6spd. Both make the same noise. The litters are hydraulic when they lose pressure on shut down they chatter

Re: Knock sound when turning car off
 

The litters?? Im not sure I know what that is? So I can assume that
all 6spds make this noise then? Thanks for the reply.

Re: Knock sound when turning car off
 

lifters, sorry I was on my phone. autospell hates me sometimes

Re: Knock sound when turning car off
 

Re: Knock sound when turning car off
 

has nothing to do with it. this is a mechanical function of the engine, nothing more. nothing you can do about it unless you run an accumulator

Re: Knock sound when turning car off
 

Holy smokes, forgot I even started this thread :|

It ended up being my cooling fan. Seems that it was slightly off-balance and rubbing around the outer rim of the fan.

Easiest way to find out if it's the fan is to have someone else turn your car off after the fan has been running.

Re: Knock sound when turning car off
 

I get 2 ponits ;)

Re: Knock sound when turning car off
 

my fan doesnt rub, my lifters are just noisy

Re: Knock sound when turning car off
 

Thanks for the reply. My car is not a turbo and I understand what you are saying about the ticking of the cooling exhaust on shutdown. My issue is not those. I usually do let it idle a min. or so before shutdown. I am wondering why the clunk with the clutch pedal not pressed and no clunk when it is pressed in on shutdown. I have heard of thers with this issue I wonder if it is all 6 spds and is normal? I only run 93 octane. It dosen't sound good. Thanks.

Re: Knock sound when turning car off
 

No problem Infinite. How would that not happen when the clutch is pressed in if it's the lifters? also please see my other post for more info on this. Thanks!

Re: Knock sound when turning car off
 

Most of the time the fan is just hitting something which cause the noise but the engine can be at fault too. But it can be the fan, the coolant, or throttle body that cause the sound. Better check all the car parts to be sure.

Re: Knock sound when turning car off
 

coolant doesnt make a knocking sound, nor does the throttle body.

The M112 motors have hydraulic lifters... When they lose oil pressure on shutdown they collapse, causing valvetrain chatter for the last few revolutions of the motor as it spins down. Thats what you are hearing. If it were the fan it would be a constant sound as the fan would be hitting that same point everytime it engaged.........................