Oil Pressure before & after AFM/DOD Delete

[01burban]

should there be any difference in Oil Pressure before & after AFM/DOD Delete???

 

Before the repair I could swear that when warm, idle on my 07 5.3 suburban was at just under 40 psi for oil pressure.

 

After repair.... (all new parts mentioned are OEM GM) new plain valley cover, new oil sending unit & deleting the screen just below it ( which was spotless btw), new cam, 16 new hydraulic lifters (tossed the 8 AFM lifters as 1 of them was seized closed). warm idle is at 22ish, 2000rpm just over 40 and higher as it revs further up.

 

Is it possible that by removing all the crappy AFM items and that oil screen just below the sender sensor that on idle there is less oil restriction causing a lower pressure?

Maybe the sensor is just reading different than the original? Only replaced it because it was the easy ideal opportunity to do so at 140k.

 

 

 

Ron

[diyer2]

Oil pressure is important but the real deal is Gallons Per Min. IMO.

[Jsdirt]

Melling is what I will install when it's my turn. They've been around for decades. Quality stuff, even still today.

[Jsdirt]

Yep - flow is the true measure.

 

Did you block off the towers in the lifter galley during the modifications? If not, those will puke oil constantly, resulting in low flow. There's a modified plate with o-rings that go on every tower, and seal them up.

 

[01burban]

Is there a mechanical pressure tester other than the one that mounts to the oil filter? Thats the only one I am familiar with.

 

Yes the valley cover replacement was fitted with the AFM tower o-ring blockers.

 

Here is a link that some may be familiar with but it was my only sanity to this AFM failure... http://lt1swap.com/afm_delete.htm He listed all the right parts for the job.. cam, valley cover, lifters & retainers... also re-flashed the ECU for a reasonable cost and turn-around & very knowledgeable about the whole process

 

Engine now sounds amazing and strong. Used to use a qrt of oil in between changes... going to see what happens on my next oil change

[01burban]

I thought about the oil pump replacement also but I had no pressure issues in the past and just wanted this thing back on the road asap. Didn't want to deal with that pesky pickup tube bolt that can barely be accessed without lowering the oil pan... no patience for it after what I had already been working on everyday after work for a few hours a day. I agree it was the ideal opportunity do replace the pump and pickup o-ring, but financially I was tapped on this project as I also need new front CV axles (my next post).

 

Hammer Head... do you recall if your pump was oem or aftermarket? Just curioss as to what others are installing if I ever come across that repair.

[Jsdirt]

Just a regular oil pressure gauge. It normally screws into the sender port, or some other port in the block.

 

http://www.harborfreight.com/engine-oil-pressure-test-kit-62621.html

[dsr611]

I had The AFM-DOD kit installed on mine back in January, and pressure before the kit was installed would drop to about 25 psi at idle and up to right at 40 psi under load. After I had the kit installed, pressure is running about 40 psi at idle and about 55 psi under load, but I also had a new oil pump installed. I spoke with several mechanics/shops and they all recommended installing a new oil pump along with the kit.

[Justin101714]

I'd check the pressure with 2 gauges, one at the sender and one at the filter. This will tell you if you happen to have camshaft bushings worn or the regulator valve in the pan is stuck open. The pressure shouldn't vary too much between readings. The specification for this engine is right around 22 at idle. But out of all the 5.3's I've worked on, once the pressure starts getting on the lower end like that, there's normally something not quite right

 

 

Sent from my iPhone using Tapatalk

[01burban]

I could of easily swapped back in the old sender as a test but rather not fight that location... Is there an easier more accessible location to tap into with the mechanical gauge?

 

thanks Jsdirt for the HF link... my favorite go to store for when you got to have it right this minute! And its only 15 min. from my house!!!

[Jsdirt]

No problem - there's usually one near everyone here in the Northeast, and if not, just a click away on the net.

 

Might not be the best quality stuff, but will get the job done anyway. I'd test it with a known pressure of compressed air, so that you know how far off it is. I do that with any product made of chinesium.

[dsr611]

Hammer Head... do you recall if your pump was oem or aftermarket? Just curioss as to what others are installing if I ever come across that repair.

Aftermarket...Melling pump

[newdude]

Have you checked oil pressure with a mechanical gauge? If you really want to be sure, I'd check it with one. A 6.0 HD engine (non AFM) runs 24-30psi hot idle per the gauge in the cluster, and the 2012 1/2 ton I had before that with AFM 5.3 ran around the same hot as the 6.0, so I am going with normal on the oil pressure.