Oil pressure sanity check

[iamdub]

Yeah paid $25 for the part and $15 to ship. It is what it is. They put the right address on it, so I am not going to make a big stink about it. It's really fedex's fault but they also don't give a shit.

My response was intended to show my interest in the outcome of plugging the AFM towers. I don't know of anyone that has done just that so they were able to have a direct before and after comparison. Some say the towers don't leak, others say they can and do. You doing this may prove something.

 

[iamdub]

Yeah, still kicking myself for not plugging that dumb thing but at least it's good to see dropping the pan doesn't require dropping the diff.

I doubt the relief valve causes issues at idle though. I probably don't even have any issues and I am just chasing ghosts.

That relief valve is to bleed off pressure from the AFM system engaging and disengaging. Unless it's leaking, it can't affect the oil pressure anywhere below it's active threshold which is supposed to start at 55psi.

 

[ls1frc]

My response was intended to show my interest in the outcome of plugging the AFM towers. I don't know of anyone that has done just that so they were able to have a direct before and after comparison. Some say the towers don't leak, others say they can and do. You doing this may prove something.

Yup. And pulling intake manifold is easy. Truck still at the shop, but weather is heating up next week finally. I'll do it over a lunch break. I found like 10 posts saying Johnson lifters dropped oil PSI by 10 though, that is likely all it is. It's too quiet to have a real problem. But $35 and an hour of work is no big deal, may as well try.

That relief valve is to bleed off pressure from the AFM system engaging and disengaging. Unless it's leaking, it can't affect the oil pressure anywhere below it's active threshold which is supposed to start at 55psi.

That's what I figured. What about the relief valve in the pump? Does that work same way? I used the standard spring. Not sure if the 10% stiffer spring affects idle at all.

 

[Geotrash]

What he says makes sense. I think @Geotrash found he could do it this way on his ride.

Sorry for the delay - been out boondocking with the camper. Yeah, that’s correct - didn’t have to drop the diff to get the oil pan off.

By the way, I ended up not plugging my AFM towers after all, and used the GM flat valley pan with the seals. I did replace the pressure relief valve in the pan with a new one, though plugging it probably would have worked out fine also but I was trying to minimize the number of variables. Either way though, my oil pressure has been fine since I completed the job.


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[iamdub]

What about the relief valve in the pump? Does that work same way? I used the standard spring. Not sure if the 10% stiffer spring affects idle at all.

Basically, yeah. The valve in the oil pan is for the AFM system, the bypass in the oil pump is for the total system maximum pressure.

Putting in a stiffer spring or shimming it or what have you raises the "full open" psi. It won't really raise the pressure anywhere below this. It will some since it's a linear type, but nothing you'd see at idle.

 

[ls1frc]

Ok i aint touching it then. Ive read people who had 12 to 15 psi on brand new vehicles. If it bothers me in summer ill just run a 10w 40.