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Gary, ASE Certified Technician
Category: Chevy
Satisfied Customers: 804
Experience:  Senior Technician
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I changed my oil pressure sensor and filter under it. My oil

Customer Question

I changed my oil pressure sensor and filter under it. My oil pressure is fine now but now I have a tapping/tick that is there from the time you start engine and never goes away when warm. It increases when speed and rpm increase. Trying to determine if it is a lifter or something else. My only other question is it has another noise in lower part of engine when first cranked, like maybe something rotating.
Submitted: 11 months ago.
Category: Chevy
Expert:  Gary replied 11 months ago.

Hi there,

Your noise is most probably roller lifters starting to fail.

Very common in the LS engine.

The lower noise is also a concern.

Have you measured the oil pressure with an accurate gauge?

How many miles on this engine?


Customer: replied 11 months ago.
I have not checked the pressure with a different gage. I changed the sending unit and filter and my pressure showing fine.I have 242000 on the motor.
Expert:  Gary replied 11 months ago.

Wow, that is good mileage from one of these.

What oil did you refill the engine with this time?

Does the ticking sound come from one side of the middle of the engine?


Customer: replied 11 months ago.
The tick sounds like it is coming from the passenger side.It just has conventional 5w30 oil.I show the engine as an LMG because the VIN # ***** is the 8th digit. Just want to make sure we are talking about the same engine.When you are saying the rolling lifters, you are meaning the lifter under the push rod and rocker arm correct?
Expert:  Gary replied 11 months ago.

Your engine have AFM (drops from 8 to 4 cylinders under cruise condition)?

Yes the roller lifter (cam follower) operates to pushrod then the rocker arm.

The oil is correct spec.

If you are keen you can remove the passenger rocker cover, get a feeler gauge of about .010, and push it between each rocker arm and the valve stem tip with the engine running.

When you find the one which is ticking, it will go quiet momentarily.


Customer: replied 11 months ago.
it does have AFM.Sorry for asking for clarification on the roller lifter name, just I had not heard it called that before.Would it throw much oil with the valve covers off.
Expert:  Gary replied 11 months ago.

Hi again,

AFM is great on paper, but I have seen many failures from roller lifter failure.

Can be the the "zero lash part" of the lifter that normally gives quiet operation, can be roller wheel or axle failure which can give a squeak to tapping noise, can be a lifter rotated in the block which gives permanent AFM on that cylinder and hence permanent misfire.

Does throw a little oil, but the test only takes about 30 seconds or so at idle.

I set up a large "splash shield" or box cardboard or similar which absorbs some oil and keeps most of the inner guard components.

You are the 3rd customer I have had in the past few weeks with an AFM engine issue.

Hope this helps.


Expert:  Gary replied 11 months ago.

Hi again,

I hope my advice has been of assistance to you.