Jump to content

AFM Lifter failure cause


CDNSS

Recommended Posts

So the Oil Pressure Sending Unit / Sensor and filter screen are located at the front of the engine under the throttle body?

 

All prior posts - videos - in this thread indicate this oil pressure sending unit / sensor and filter screen are at the rear of the engine.

 

 

Link to comment
Share on other sites

So the Oil Pressure Sending Unit / Sensor and filter screen are located at the front of the engine under the throttle body?
 
All prior posts - videos - in this thread indicate this oil pressure sending unit / sensor and filter screen are at the rear of the engine.


On a 5.3 it is located just under the throttle body. If you’re standing at the front of the truck looking at the throttle body, it will be just to the left of it.

The Haynes service manual describes the removal and cleaning procedure.
Link to comment
Share on other sites

IMO

If the oil pressure sending unit screen is plugged there are similar deposits in other places inside the motor.

It's called sludge.

A better oil, filter but most likely more frequent oil changes would prevent this.

Let the fall out begin.

 

:)

  • Like 4
  • Thanks 2
Link to comment
Share on other sites

I agree use the recommended oil wt and change oil frequently  For these engines IMO. Why some have lifter issues some don’t.  However  early yrs did have defective lifters. So dirty filters are not 100% of the afm lifter issue but pbly most of the reason 

Edited by CDNSS
Link to comment
Share on other sites

54 minutes ago, 14GMCZ71 said:

OK - Man that is tons easier than removing the intake or trying a taped up socket swivel and bent up levered ratchet to try and remove it from the back of the engine.

 

Thanks for your post!

Some yrs the the sending unit is at the rear depends on yr and engine size 

Link to comment
Share on other sites

2 minutes ago, CDNSS said:

I agree use the recommended oil wt and change oil frequently  For these engines 

Not true!  You can and will have issues even being the 5K OCI guy it's GDI.  Using the correct products is all you need.

Link to comment
Share on other sites

IMO
If the oil pressure sending unit screen is plugged there are similar deposits in other places inside the motor.
It's called sludge.
A better oil, filter but most likely more frequent oil changes would prevent this.
Let the fall out begin.
 
[emoji4]
Hard to understand how sludge could be a problem with the temps these engines run and the types of oil that are available today. My brother in law routinely keeps his Tahoe 300K miles he's on number 4 and a high mileage p/u. He follows manufactures service schedule. He just got a 13 his first cylinder deactivation engine, this will be interesting. He only had one failure, a rear end went out on a suburban right at 300K a couple of rides ago.


Sent from my iPad using Tapatalk
  • Like 1
Link to comment
Share on other sites

I have the 5.3 V8 and here is my maintenance record to date - Truck purchased new on 8-16-14 - All work done by me.

 

On two oil changes the miles traveled was higher - couldn't get to it.  I use MS Excel and keep this in a spreadsheet.

 

Truck now has a little over 28,000 miles.

 

image.thumb.png.0ba210d2f5e26b413adb741b43faf5c8.png

 

 

image.thumb.png.a79df002a7f13710ba42495dd2e396b7.png

 

 

Edited by 14GMCZ71
  • Like 1
Link to comment
Share on other sites

I said my opinion and let the fall out begin.

I know how most regulars on here feel about most things.

I also know from the regulars posts their history on maintenance.

 

I will do oil changes that make me feel good with the products I like.

My way of doing vehicle maintenance has an excellent history having never had an engine failure of any type.

And keep in mind I buy used vehicles.

 

And IMO any motor can get sludge if not properly maintained.

 

:)

 

 

  • Like 2
Link to comment
Share on other sites

Between the Melling and the GM video's there is a ton of enlightening information. I took special note that both sources say the failure is caused by a 'mistimed' switching event. That is, switching, while off the base circle. Switching events on the ramps or nose 'bite' the pins while under load damaging the outer shell "shelf' locking it to the inner assembly. I also noticed that Melling, speaking of the LS motors ONLY specifies 27 psig as the minimum latching pressure while GM speaking of AFM in general specifies 22 psig as the minimum. Odd as they do not concern themselves until oil pressure drops to 19 psig hot idle.

 

So the question is what causes a 'mistimed' event? Pretty sure the ECU and the solenoids in the VLOM don't step out of time. Ones and Zeros and all.  So it seems reasonable that plugged filters or restricted channels hinder rapid pressure up of the lifters taking longer to reach the 22/25 psi minimum. Time in a motor is degrees of rotation correct? It positional thus the ECU fires and the solenoids hit on time but the oil pressure rise time lags long enough for the cam to turn to the ramp or beyond. Ops, horse is out of the barn! :lol:

 

On ‎2‎/‎9‎/‎2019 at 8:19 AM, diyer2 said:

What oil and filter you using?

How often changing oil and filter?

:)

On point. 

Link to comment
Share on other sites

  • 3 weeks later...

Oil pressure sensor locations from Alldata for my 2011 Yukon, 5.3L. Both are at the rear of the engine and the filter screen sits inside the hole under the pressure sensor.

 

For those running frequent oil changes, you may consider sending off your oil for analysis (Blackstone Labs, etc.). Other than an 800 mile break-in change, I run 15,000 mile OCI with Mobil1 EP and Mobil1 filters. I've never had an issue, don't consume any oil between changes, and the oil tests fine. Current odo is 124,000 miles. The only repair in 8 years was a warranty seal replacement on my midshaft differential. 

OilPressureSensor_woRPOLZ1.JPG

OilPressureSensor_wRP0LZ1.JPG

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.