My engine will make a random knocking noise while its idling. I have been told it was the flex plate and all sorts of stuff.

heres the deal. when I switch from 10w30 to 20w50 the dang noise goes away mostly. it still knocks randomly but much less.

this pretty much confirms that its in the engine somewhere.

When it knocks, it seems to effect the idle/exhaust sound slightly.

It does not make a knocking noise when driving, so im pretty sure its not any bearings.



Could it be the oil pump shaft? thats the only other gear in the motor I can think of.

could the timing chain make a knocking noise?


thanks

 

i think the bearings wouldnt knock all of the time b/c when youre driving theyre getting more oil, not + tho.....hows your pressure?

 

there is a heat shield between the motor mount and manifold. on mine the one the driver side has limited space and it rattles once in a while so i jus give it a little bend and it goes away could be that but maybe not, worth a try though. good luck

 

Ya, my heat shield was bent too.

I read that somewhere and sure nuff... but apparently that was only part of the noise.


Thats the other thing... my oil pressure is constant and around 45...

I read about the transmission linkage thing, which Im gonna check tomorrow. The thing is, It seems to go away with the heavier oil. I'm gonna get 2 ratchet straps and hold the motor really still by straping it to the front axle and see if it is still there. that way I can see if it has to do with loose motor mounts/rattling shaking noises.

im gonna leave the 10w40 in it for a few days so I can take it by a shop and let them hear it again.

thanks for your ideas

 

Yes to the timing chain causing a knock. I've had it happen. The plastic coating was worn down to the metal on one tooth. I was lucky it didn't jump time.

 

Another theory of late on the board is that these knocking/rattling noises are caused by piston slap or a loose wrist pin. Another guy, Trucklover(?), has a very similiar problem that he just can't track down. I'm starting to open up to the wrist pin theory myself. How many miles do you have on your engine?

 

Does it sound like the sound clip here: http://www.pistonslap.com/photos.htm ?

 

mine has 108k really not extremely high.

thats very interesting. I'm trying to imagine how serious that would be... the piston slap or wrist pin

 

Well, they are really one in the same. If you have really sloppy wrist pin to piston clearances, the piston will slap against the combustion chamber on the exhaust stroke. If the wrist pin is also floating around free from the rod, then it will also cause damage to the cylinder walls. As far as time/money to repair, I would rather have a cracked head.

 

LOL,

"Like a knock!"

Just need them to team up with Dodge and install a 46re tranny behind that thing.