Engine knocks

[Chargerfreak]

Hello all.

When i start my car it sounds perfect. Than after driving a while and it's warm/hot and i turn the car off and wait a minute and start again it's knocking a while. The knock also follws the rpm's.

Is this a typical lifter gone bad?

It' a 383.

Chris.

[Chargerfreak]

 

[ipstrategies]

I am no mechanic..
but I have always thought knocking sound (lower end of engine)
tapping type sounds top end (lifters )  and my 383 lifters tap some when I first start if it has been sitting for a while.

I am sure someone will post some ideas? 

[y3chargerrt]

Knock with engine rpm sounds like bottom end to me. Hows your oil pressure cold and hot?

[frederick]

Alsways very difficullt to tell over the internet.

But is it knocking at
engine speed = crankshaft, bearing problem
1/2 engine speed = camshaft, lifter rocker etc problem
faster than engine speed, look at ancillaries; alternator, waterpump, etc

Would it be possible to make a video of it?

[Chargerfreak]

Ok, will check these things this weekend.

You also kept in mind that it only happens when warm and started.. And then it fades away again after a while..??

Thanks already,
Chris.

[tan top]

got any video / sound of the motor running   

[Chargerfreak]

Ok first this: oil pressure cold is 55 psi and warm little over 60..

Also had my engine checked a while ago, and they tested compression and came up with this.

1 - 9          2 - 9,5
3 - 9,5       4 - 10
5 - 9          6 - 9,5
7 - 10,5      8 - 10

The guy who checked my engine also wrote on the list:

Maybe valves to tight. Engine is noisy, collapsing piston or bearing and lots of underpressure.


Chris.

[Chargerfreak]

O and by the way, video or sound is difficult for me to post. Still i think it's a hydraulic problem since it only occurs when the engine is turned off when warm and then started.. Mechanical problem would make the sound all the time right?

Chris.

[twinscrew698]

Just by chance ,make sure torque converter bolts are tight!
That will resemble a knock also!

[Tilar]

So will a cracked flex plate.

[Chargerfreak]

But it doesn't knock all the time....

Chris.

[twinscrew698]

That will do it also! Cracked flex plate and or loose converter!!

[Tilar]

Put it in gear with just a slight load on the engine and see if the knock goes away.

[firefighter3931]

O and by the way, video or sound is difficult for me to post. Still i think it's a hydraulic problem since it only occurs when the engine is turned off when warm and then started.. Mechanical problem would make the sound all the time right?

Chris.

It sounds like one or more of your lifters are bleeding down when the engine is warm. 



Ron

[Chargerfreak]

Thanks all!

I still think lifters too. Is there a way to tell for sure? Before i just go replacing them? And to determine the side, just listening?

Still will check flex plate, and torque conv. bolts too.

Again thanks,
Chris.

[Sublime/Sixpack]

I find that an automotive stethoscope helps in pin pointing noises.

[Tilar]

If it is a flex plate or loose converter bolts, the knock will go away if you put it in gear, put your foot on the brake and bring it just a little above an idle.