Oil pump shim

[Hammerhead]

(05-20-2017 )slowpoke Wrote:  just shimmed my oil pump again had 5 dimes, now upped to 8 soon as i start engine oil pressure only climbed to 32 psi (used to be 42 when cold) then fluctuated to 28 back to 32 up and down for about 4 minutes then climbed to 45 at 900 rpm once it settled i raised rpm to 1300 and it hit 51 psi. what pressure does the bypass ontop of oil filter blow of at. i pulled allen plug out to check thats its up datted it is. didnt try to pull it out though. could that be what caused fluctuation was a little scarry. bolts in oil pump o ring to out side by cotter pin. oil filter 2 days old.

Also, something else to consider is that when you pull the dogbone assembly from the pump, you are opening up the pressurized oil rifle system at is very lowest point. Gravity will dictate that oil will flow down and out the opening.
Once restarting the engine after this, there will be air bubbles and gaps in the system that need to be evacuated which will cause some slight fluctuations for a short time.
If this only happened on the first startup since the mod, I would figure that this is exactly what took place.

[slowpoke]

okay thanks hammerhead that was the info i needed, big help were is the pressure sensor located cm871

[slowpoke]

never mind googled it found were it goes thanks again

[Rawze]

I see something that has been missed in this discussion. I have seen people pull their pan off and re-install it, causing the o-ring to fail where the pick-up tube meets the oil pump. Sometimes you have to take off this pick-up tube to get the pan off, and sometimes not. Either way, if that o-ring starts leaking, you will get fluctuations in the oil pressure because it is sucking air. I have seen people destroy engines because that o-ring was sucking air and aerating the oil.

-- Just letting you know since no one has mentioned it.

[slowpoke]

Guess Im going to get really familiar with my oil pan , well running down the road at 63 mph --1290 rpm and temperature 205 it ran at 39 psi thats up from 33 with 5 dimes. Stock used to be 30 , 31. Stock and Hot oil 225 would drop 27-28. Thats why I shimed.
Thanks Rawze.

[Hammerhead]

(05-21-2017 )Rawze Wrote:  I see something that has been missed in this discussion. I have seen people pull their pan off and re-install it, causing the o-ring to fail where the pick-up tube meets the oil pump. Sometimes you have to take off this pick-up tube to get the pan off, and sometimes not. Either way, if that o-ring starts leaking, you will get fluctuations in the oil pressure because it is sucking air. I have seen people destroy engines because that o-ring was sucking air and aerating the oil.

-- Just letting you know since no one has mentioned it.

Thanks for mentioning this. My big ugly work truck and the couple buddies trucks all had sufficient clearance that a blind man could remove the pan and not bump anything.
I've got another buddy that wants me to help him do this to his pavement princess, so I'll keep that in mind when we take that on...

[Rawze]

(05-22-2017 )slowpoke Wrote:  Guess Im going to get really familiar with my oil pan , well running down the road at 63 mph --1290 rpm and temperature 205 it ran at 39 psi thats up from 33 with 5 dimes. Stock used to be 30 , 31. Stock and Hot oil 225 would drop 27-28. Thats why I shimed.
Thanks Rawze.

If before you shimmed it, you were dropping below 33 psi or less stock going down the road above 1,000 rpms with water temp at 185-F, you have something wrong. Should only get down to 32 or so under high water temp 215+ and 240F on oil. If it was only getting around 30-32 in normal driving ...


YOU HAVE A SERIOUS PROBLEM WITH YOUR ENGINE!!!--- RAISING THE OIL PRESSURE IS MASKING YOUR PROBLEMS!!!!!!!!!!!!!!@!!!!

DON'T STICK BAND-AIDS ON ACTUAL PROBLEMS!!!



That or the oil pressure sensor is bad.

[Billdozer2]

(05-23-2017 )Rawze Wrote:  If before you shimmed it, you were dropping below 33 psi or less stock going down the road above 1,000 rpms with water temp at 185-F, you have something wrong. Should only get down to 32 or so under high water temp 215+ and 240F on oil. It it was only getting around 30-32 in normal driving ...


YOU HAVE A SERIOUS PROBLEM WITH YOUR ENGINE!!!--- RAISING THE OIL PRESSURE IS MASKING YOUR PROBLEMS!!!!!!!!!!!!!!!!!!

DON'T STICK BAND-AIDS ON ACTUAL PROBLEMS!!!

That or the oil pressure sensor is bad.

I was thinking the same thing. I rarely pull heavy (40k+), but when I do, I monitor my oil temp/pressure when climbing the one big hill I have to deal with. As my coolant temp bounces off of 210 with every cycle of the fan, my oil hovers around 233 temp and 33 psi. That is at 1700 rpms and 20 psi or so of boost. (Stock pump no dimes)

Slowpoke, I agree with Rawze. I think you have other problems.

[redbeard]

I'm still not convinced that the new super duper up graded oil bypass valve is doing it's job.

When I replaced the bypass valve on my 2250 with the new "super cure all bypass valve" the o-rings were very loose in the bore. I called and talked to numerous techs and they all told me that that was they way they fit.

Seems to me that if the oil slides past the valve, how can it regulate it?

I'm running a bypass filter, and doing oil changes at 14,000 miles with the mandated motor.

Oil pressure has been an issue since the day I got it and fluctuates greatly between fresh and at changing.

43psi with 8 dimes in pump and fresh oil, and starts creeping down to 35 at oil change running down the road at 1400rpm.

New filter and oil pops right back.

Changed rod bearings at time of pump mod just because wanted cheap peace of mind, 225,000 miles on engine and they looked pretty good. Engine sounds good and tight