Oil pressure / pump problem

[ToLows10]

So.... I think I might have a problem with my oil pump. To be more exact the pressure relief spring.

I've always changed my oil viscosity with the seasons to accommodate different oil temps. Normally between 10/15w 40 in the summer months and 5/10w 30 in the winter months. I constantly monitor my oil temps and plain as day can see the influence temp has on viscosity and pressure. I've always had good oil pressure, 60 psi at cold start up, 10-15 psi at idle once at temp and about 10 psi per 1000 rpm after idle up to 60 psi. That's not so much the case any more. It's about 40 psi at cold start up. Idle pressure @ 950 rpm is 10 psi if oil is under 180 degrees. As soon as my oil gets up to 215-220 degrees my pressure drops to about 5 psi. If my idle drops to say 700 rpm my oil pressure dummy light comes on. As soon as i tap the gas oil presure jumps right up... 1500 rpm 20 psi but oil pressure wont exceed 40-45 psi. Even at 6000 rpm. AND IM RUNNING 20w 50 NOW JUST TO GET THESE RESULTS.

Any thoughts?

I'm thinking oil pressure relief spring. Ya think it might be stuck open or something? It's a Meiling 10% +volume stock pressure pump.

[wikd]

how long has the engine been put together??? and when it was rebuilt were new cam bearings put in???

was the pick up welded onto the pump??? and when was the last time you changed the oil???

the reasons i ask all of this is because if it is a new motor build i would say yeah it could be the pressure spring or the pump has issues... if its been built for a while then i would suggest bearings... if it was rebuilt without new cam bearings how many miles did it have before rebuild...

all of these things can and will affect oil pressure...

heavier weight oils in a weak pump will not produce higher oil pressure levels... in fact if the pump is weak it can result in lower ppressure levels than a thinner oil as the pump cant push and draw the thicker oil as easy as it can thinner oils...

these are just things to think about...

[Diabolical]

I am leaning towards the bearings as well.. Specifically, The cam bearings..
Unless that thing has seen some really high rpm's.. That spring is not the issue.

Where are you taking your readings from? The back "China walls" of the block?
Can you access the one by the filter?

John also hit it good with the pick up..
If that pick up is loose you will have really bad oil pressure.

[ToLows10]

Engine is two years old. Less then 5000 miles on. New (not rebuilt but brand spanking new everything) block, crank, rods, pistons, and all the bearings. I Change the oil every two months no matter how much it's driven (except when it sits in the winter). Oil pump is new also. M55 I beleive.

The pick up is a long story...

My oil pump came with a bolt on pick up, my moroso deep sump pan came with a press in pick up. The bolt on pick up wouldn't fit the pan, the press in pick up wouldn't fit the pump. So I cut the flange off the pick up that bolted to the pump and welded it to the pick up that came with the pan then I bolted the whole assemblly to the pump so there was no welding done to the pump. If I recall correctly there was a gasket between flange and the pump. Maybe that could be it.

I guess I'm just gonna have to pull the motor and investigate. I planed on doing some BIGTIME suspension mods and frame work over ther winter anyway. Guess I'll be doing motor work too. Lol.

I don't know why I'm Laughing cause this could potentially be a big problem I'm just thinking (when I say thinking I really mean praying) its only the pump.

[Diabolical]

With everything being new..
The first place I would go is that pick up.
Especially after reading your issues with it.
Could be a simple fix.

[ToLows10]

I am leaning towards the bearings as well.. Specifically, The cam bearings..
Unless that thing has seen some really high rpm's.. That spring is not the issue.

Where are you taking your readings from? The back "China walls" of the block?
Can you access the one by the filter?

John also hit it good with the pick up..
If that pick up is loose you will have really bad oil pressure.

Motor has never seen over 6500 rpm (msd chip) I always I mean always warm the motor (watching oil temp not just water temp) before getting into it.

I take my oil pressure from the back of the block, behind the intake. I have my oil temp sender installed in the provision in the oil filter area.

The problem started this summer, progressively got worse, and seems to have plateaued

[ToLows10]

With everything being new..
The first place I would go is that pick up.
Especially after reading your issues with it.
Could be a simple fix.

I hope

[wikd]

yeah if there is a pin hole in the welds on the pick up it will cause all kinds of issues...even if it has cracked over time i would start there...

could be something as simple as that...

[mytmouz]

What brand oil filter? And the Mellings had a problem with cracking due to a redesign...

[ToLows10]

Oil filter is a Fram HP4.

[Rickracer]

You would NOT BELIEVE how many oil pressure problems I've heard of with Fram filters recently, I'd change that POS for a real filter, (Wix, NAPA Gold, Purolator Pure One, etc.), and then see what you've got. :wink5: :cool4:

[mytmouz]

Ditch the Fram first thing. I speak from experience. I use either a Wix, or the premium NAPA or Carquest premium filter, they are made by Wix...

[ToLows10]

I'll run to the parts store tonight (i really dont think its the issue but i can check for $10 and 30 minutes of work.) Any thoughts on a descent filter I could pick up at Advanced, Pep Boys, or Auto Zone. No Napa's close to my house.

I'm gonna try (and hope it works) but I feel I need to explain why I don't think this is the problem... I've always ran royal purple. Anywhere's between 5w 30 and 15w 40 pending the seasons and operating oil temps. Need less to say I change the oil about every two months or 5-800 miles. Always using a new filter. This problem has been progressive and no matter if the filter was new or had a couple hundred miles on it.

I was using royal purple 10w 40 since September and my longest oil change interval of 3 months (still less then 1000 miles). Did an oil change in December because the problem had worsened to the point that I couldn't let the truck idle once at temperature cause the oil pressure would drop. My initial thought was that the oil had broken down (I heard rumors of Royal Purple full synthetic doing this) and lost its viscosity and lubricity. I'm in between jobs right now so I couldn't afford the $8 a qt and 8 qts for an oil change with Royal Purple so I improvised. I was able to acquire 4 gallons of Shell Rottela T deisel 15w 40 (friend is a truck driver) for free! Did my oil change with a new filter and the problem was worse. I couldn't beleive it. I learned two things. One is that Royal Purple 10w 40 is actually thicker then Shell 15w 40... And two... I have a problem. I ran to the parts store and bought 7qts of Pennzoil 20w 50 conventional oil, drained the Shell, replaced it with the 20 50, did not replace the filter and saw a noticeable increase in pressure. Even at higher oil temps the pressure was alot more consistent. Especially at idle. So even with all the differant filters (all HP4's) I doubt that every single one had a problem. Oil and filter in there now have less then 100 miles / 3 hrs on it.

Sorry for the novel but I just felt the need to explain why I didn't agree with the answer to a question that I asked.

I am still gonna try it on the simple fact that all the filters used were Fram HP4's and this isn't the first time I've heard of problems with Fram filters.

Thanks for all the ideas. Please keep up with the suggestions. I'll post with how the filter change goes.

[Diabolical]

Cool

[83blazerV8]

ditch the synthetics we had a oil presentation at the shop all the synthetics did no better than conventional on bearing drag the only oil that didnt allow the bearing to stop was a H.D. motorcycle oil. i run 30wt castrol HD and wix filter up here in washington all year long consistancy is key to diagnosing problems

[Rickracer]

I've heard a LOT of BAD STUFF about Royal Purple recently as well. Advance Auto carries Purolator Pure One filters, that's what I've been running on my truck since I built the motor, (since my shop does a lot of business with them), they test well and have done well for me. I've ALWAYS run either Castrol or Valvoline 20w50, and literally 100s of 1000s of miles. :cool4:

[ToLows10]

I tried to post this last night but I kept getting error messages that the server stopped responding. Either way... I replaced the filter with a parts store el cheapo filter and still have the same problem. Couldn't even make over 40 psi with 20w 50 on a cold motor. And when I say cold it was barely above freezing, so I just shut her down and put it back in the trailer. I think it's time to just pull the motor and investigate.

I'll let ya know what I find. Might be a couple weeks.

[Diabolical]

Please do..

[jameskirk1]

x2 and stuff

[RedRider85]

Sounds like loose bearing clearance. My 78 camaro 350 did the same thing. Like the exact same thing. It ended up being the main bearing clearance. Over the engines long life it manages to wallow out .014 clearance average. The motor wasn't knocking or making any noises, just low oil pressure at idle after warm up. Just my opinion.

[ToLows10]

So I've played with the idea of big blocks and blowers, but alot my friends have kinda steered me towards doing what I've been saying I was gonna do all along...and that's body work. I have to pull the motor for the oil pump issue anyway so I figured it's time. Suspension and body work. I'm going to do as much fiberglass as possible. Tubular control arms, air ride, something with that ugly brake booster, aluminium calipers, and maybe a complete firewall rebuild.

Last year I was in a rush to have everything done on a time line. Not this year! I would like to have it done by May but if it's not... It's not!

I'm not sure where to start. I'm thinking if I'm really gonna go though with this firewall idea that's the place to start because that will be the foundation for everything else. My idea is to make a nice flat firewall. One peice, no bends, set back about 2-3 inches. Plus front wheel tubs if nessesary. We'll see. Any way, here's some pics of the tare down. I worked in the trailer all day. Lol

http://i1092.photobucket.com/albums/i408/ToLows10/80220e01.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/cd163be3.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/be62d197.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/7b88d2a8.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/156dfa9b.jpg

COUGH COUGH... Might I add GO RAVENS!!!

[ToLows10]

So I got the motor pulled today. Also took the doors off. Maybe I'll start pulling the front suspension apart tomorrow...or maybe I'll just drink beer and watch football we'll see. I'm at least gonna put the engine on the stand (it's still dangaling from the engine hoist) and pop the pan off to see if there's anything obvious going on.

Here's some pics.

http://i1092.photobucket.com/albums/i408/ToLows10/4be0e72f.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/2c28ba0b.jpg
Got the girlfriend to take the headers off

http://i1092.photobucket.com/albums/i408/ToLows10/b1cc0458.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/44a66782.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/dfd81598.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/b9053114.jpg

What ya think of that header? Almost cracked all the way around! It was the drivers side.

[m.a.d.]

well, atleast you found the crack

[ToLows10]

well, atleast you found the crack

Lol

[ToLows10]

So my girlfriend said she was going to the mall. Well she did. And beings my girlfriend is who and what she is, a trip to the mall involves a stop in the sears tool section. I was watching football and she comes home with this!

http://i1092.photobucket.com/albums/i408/ToLows10/f8a5daa5.jpg

One badass 3 ton floorjack, jack stands, and a creeper. Something like $150 OFF! Right! So she paid $99 for it AFTER TAXES! She said she feels better with me working under my truck with a real jack.

But the important part is having a girlfriend that go's to the sears tool section without me and buys tools.

http://i1092.photobucket.com/albums/i408/ToLows10/3bbf5eca.jpg

Oh... We already had the dog. Lol.

[ToLows10]

Well. I know it took longer then expected. I've been extremely busy with my new job and buying a house and what little bit of time I've had here and there has been dedicated to the chassis. Either way I spent all day yesterday fooling with the motor. I checked a couple bearings and nothing looked out of wack. Clearances were within spec too. I also installed a new oil pump. It's meiling p/n 10552C. Obviously I haven't started it yet but that will soon come. Either way... Hopfully this new oil pump does the trick. Here's some pics. I installed some new shiny stuff and painted it too. Lol.

http://i1092.photobucket.com/albums/i408/ToLows10/97449974.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/11e9a7d8.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/1a16edb4.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/5a5ad876.jpg

http://i1092.photobucket.com/albums/i408/ToLows10/6edcc7ad.jpg

[spib]

:rock::rock::rock::rock: