Lifter knock

[cowman79]

So I pulled the motor out of my truck that had a knock and the only thing I have found out of the ordinary is that atleast two of my lifters can be compressed very easy. My question is how much force should it take to compress the lifter and would this cause my truck to have a knock. I have not pulled the heads yet but I have pulled the oil pan and all rods and wrist pins seem to be tight.

 

[Cincinnati Guy]

How do the others compress compared to the two you checked?

 

[cowman79]

I have checked most of them with the rocker arms tight and the rest of them are firm that I can tell I guess I need to pull the rockers off all of them and check the resistance.

 

[BigDiesel]

They should be stiff enough that you have to use a vice and a socket to compress them as they stay pumped up for a long time. I have an old set out of my engine and after 5 months they are still hard. They are also quite cheap if any are bad replace all. I just put a cam and head studs in my engine and while firing up for the first time had a tick/knock like yours until my lifters adjusted to my new cam.

 

[cowman79]

Well If I replacd one I would replace all of them. I pulled the motor because of the knock I had I am really wondering if they would have caused the knock I had. The big reason I am concerned is that the motor I just put in consumed about two gallons of antifreeze in about 100 miles. I am hoping it is an air pocket but only time will tell. I might have to repair the original motor and stick it back in.

 

[BigDiesel]

A bad lifter in these engines will make quite a knock as the lifter has a bit of room to go before being collapsed. To make sure the bottom end isn't the culprit you could plastiguage the crank journals to rule that out. Also two gallons of coolant sounds a bit much my truck usually takes 1/2 to 3/4 gallon of coolant after burping the system after a swap. Good luck.

 

['94IDITurbo7.3]

A bad lifter in these engines will make quite a knock as the lifter has a bit of room to go before being collapsed. To make sure the bottom end isn't the culprit you could plastiguage the crank journals to rule that out. Also two gallons of coolant sounds a bit much my truck usually takes 1/2 to 3/4 gallon of coolant after burping the system after a swap. Good luck.

that 2 gallons of coolant is on the engine that he swapped in for this engine.

 

[cowman79]

I know that two gallons of coolant is a lot. I am trying to be optimistic which usually doesnt work out for me.