TheSamba.com :: View topic - High oil pressure at start up & low oil pressure when wa

Wed Jun 27, 2012 4:04 am

Fresh 2276 Turbo runs pretty well but here's my problem. At start up I get about 80psi then once its warmed up the pressure plummets to damn near nothing. I have a 26mm pump with the oil pressure booster in one of the relief valves. Running 20w50. Any Ideas?

Wed Jun 27, 2012 5:23 am

I have found that on many engines, this is normal--especially in the summer when the oil heats up quicker. My last two were anywhere from 60-70psi before they got warm, then back down to 15. In the summer heat, they hit the point where the light comes on the dash-about 5 psi or so. Does your light come on once the engine is at idle and fully warmed up? Does it do it all the time (once warm) or just idle? May be idle speed adjustment. To remedy this, I set my idle in the summer slightly higher than normal. As long as everything is setup right and the internals are getting lubed, it is fine. This is just a suggestion, it may not solve your issue.

I had this issue more when I would use full synthetic 10w30 or straight 30w oil...I now just use 15w40 Rotella w/Zinc additive and slightly raise idle speed in summer months. Your 20w50 should be just fine.

Wed Jun 27, 2012 5:28 am

smitty24 wrote: I have found that on many engines, this is normal--especially in the summer when the oil heats up quicker. My last two were anywhere from 60-70psi before they got warm, then back down to 15. In the summer heat, they hit the point where the light comes on the dash-about 5 psi or so. Does your light come on once the engine is at idle and fully warmed up? Does it do it all the time (once warm) or just idle? May be idle speed adjustment. To remedy this, I set my idle in the summer slightly higher than normal. As long as everything is setup right and the internals are getting lubed, it is fine. This is just a suggestion, it may not solve your issue.

I can understand some flickering maybe but i get a solid warning light. Another thing is that on the hwy @65mph/ 3k rpms pressure starts at 40psi after about 15min of hwy driving the psi slowly drops to almost 20psi at 3k rpms. Not healthy for the motor what so ever... I got alot of $$ into this motor last thing I want is to screw something up.

Wed Jun 27, 2012 5:39 am

Put a 30mm pump with a turbo.

Wed Jun 27, 2012 5:50 am

yes, my light does NOT flicker but stays on at idle as well. 20psi DOES sound a bit low on the freeway!

Wed Jun 27, 2012 6:09 am

smitty24 wrote: yes, my light does NOT flicker but stays on at idle as well. 20psi DOES sound a bit low on the freeway!

LOL! troubleshooting in progress... smh

Wed Jun 27, 2012 6:10 am

vince1 wrote: Put a 30mm pump with a turbo.

That would probably be the last thing I do if I can't figure out whats wrong. I'll probly check the pressure relief plugs to make sure they're not sticking before I do that.

Wed Jun 27, 2012 9:38 am

Did you check all your clearances?

The pump gears to cover would be the first to check, should be zero gear end play without the thin paper gasket in place. The gasket dictates the final end play clearance once installed.
Also check the pump body to case for fit, should be rather snug fitting in the bore.
What about your bearing clearances, all within spec when built?

Also once warm try firing the engine very briefly, idle only, with the feed line to the turbo plugged. You could be flowing to much oil through the turbo causing a pressure loss.

Wed Jun 27, 2012 9:48 am

SRP1 wrote: Did you check all your clearances?

The pump gears to cover would be the first to check, should be zero gear end play without the thin paper gasket in place. The gasket dictates the final end play clearance once installed.
Also check the pump body to case for fit, should be rather snug fitting in the bore.
What about your bearing clearances, all within spec when built?

Also once warm try firing the engine very briefly, idle only, with the feed line to the turbo plugged. You could be flowing to much oil through the turbo causing a pressure loss.

ok motor has maybe 50mi on it ha so its super fresh. all clearances are good. I do however have the sending unit tee'd off/ in line the supply line to the turbo. Any chances that would cause a misreading?

Wed Jun 27, 2012 9:53 am

You're all wrong....nobody caught this from the first post?

OP wrote: oil pressure booster in one of the relief valves. Running 20w50

Oil's too thick, and it's at too high a pressure all of the time. The oil is heating up by simply being pushed around the case, then you ask it to do actual work? :? No wonder you have no pressure.

OP wrote: At start up I get about 80psi

Really? Here's yer sign.... :roll:

Wed Jun 27, 2012 9:58 am

miniman82 wrote: You're all wrong....nobody caught this from the first post?

OP wrote: oil pressure booster in one of the relief valves. Running 20w50

Oil's too thick, and it's at too high a pressure all of the time. The oil is heating up by simply being pushed around the case, then you ask it to do actual work? :? No wonder you have no pressure.

OP wrote: At start up I get about 80psi

Really? Here's yer sign.... :roll:

Ok what is the oil temp when the pressure drops to 0?

Wed Jun 27, 2012 10:01 am

miniman82 wrote: You're all wrong....nobody caught this from the first post?

OP wrote: oil pressure booster in one of the relief valves. Running 20w50

Oil's too thick, and it's at too high a pressure all of the time. The oil is heating up by simply being pushed around the case, then you ask it to do actual work? :? No wonder you have no pressure.

OP wrote: At start up I get about 80psi

Really? Here's yer sign.... :roll:

thanks but no need to be smart here. Ill be changing the oil to 10/30 today. with 20/50 it hasnt gotten hotter than 190/200 degrees before I shut it down due to LOW OIL PRESSURE at idle and running at 3k rpms so how will a lighter oil fix the pressure problem if im already at low oil pressure when warmed up when lighter oil gives you lower oil pressure already?

oh and btw it clearly states here that at start up 82psi is the normal high.

Wed Jun 27, 2012 10:02 am

Quote: Ok what is the oil temp when the pressure drops to 0?

Pretty much between 190 and 200*

Wed Jun 27, 2012 10:06 am

Quote: The pump gears to cover would be the first to check, should be zero gear end play without the thin paper gasket in place. The gasket dictates the final end play clearance once installed.

Good but incomplete advice. The paper cover gaskets are made of different paper stocks from different sources. Some are as much as .008" thick, a pump with that much endplay would raise very little pressure hot. To do what is advised you need paper that mics at .003.-004", as that will be the pump gears' endplay, and you don't want it to be more than that. It's hard to tell the difference in thicknesses by appearance alone, put a caliper on it.

Wed Jun 27, 2012 10:33 am

wicked1lbc wrote: with 20/50 it hasnt gotten hotter than 190/200 degrees before I shut it down due to LOW OIL PRESSURE at idle and running at 3k rpms so how will a lighter oil fix the pressure problem if im already at low oil pressure when warmed up when lighter oil gives you lower oil pressure already?

I had typed up a whole response to this, then I realized it's pointless to comment until you remove that booster spring. Do that, then come back with new numbers. My guess will be you need a 5W-30 or something along those lines.

Wed Jun 27, 2012 10:49 am

miniman82 wrote: wicked1lbc wrote: with 20/50 it hasnt gotten hotter than 190/200 degrees before I shut it down due to LOW OIL PRESSURE at idle and running at 3k rpms so how will a lighter oil fix the pressure problem if im already at low oil pressure when warmed up when lighter oil gives you lower oil pressure already?

I had typed up a whole response to this, then I realized it's pointless to comment until you remove that booster spring. Do that, then come back with new numbers. My guess will be you need a 5W-30 or something along those lines.

the booster will remain for now but I will switch my oil then repost the numbers.

Wed Jun 27, 2012 11:01 am

Nothing wrong with the oil temps, that's fine.
I'd say check out the pump and work from there.
Post up what you find.

Wed Jun 27, 2012 11:11 am

SRP1 wrote: Nothing wrong with the oil temps, that's fine.
I'd say check out the pump and work from there.
Post up what you find.

thanks bud ill keep posting until the problem is fixed :D

Wed Jun 27, 2012 11:13 am

I have used 20/50 for years with 0 oil pressure problems. I know there are many here who dissagree and that is fine, to each thier own. Point is it is not the oil causing the problem, I am thinking srp1 is on the right track. I have seen a bunch of loose schadeck pumps, both end play and case fit wise

Wed Jun 27, 2012 11:19 am

I'll bet the turbo is pulling your pressure away from the idiot light sensor.

Like the engine I built using a fram bypass filter. I put a 1mm restrictor in and oil pressure is fine now.