Hey there guys

a friend logged my truck and sent me this

oil pressure problem, which on a stock motor can only be due to the head swap, lifters perhaps? Oil pressure at idle is a good 45psi, however does not go above 55psi during WOT, and goes down to 48psi at 6000+ rpms which is BAD. Taking into consideration the car is running almost one of the thickest oils Castrol 10w-60 and not seeing sufficient oil pressure without even beating on the car = low oil temp. When the temps go up, the oil will thin and pressure will be even less. Even the 10psi per 1000RPM norm cannot be met. Another thing to consider it, while the shortblock is stock it probably isnt working well with the thicker oil, and tight bearing clearances even though a certain something in the heads is causing the low-oil pressure which is forcing you to use the thicker oil.

 

a bad lifter could definitely drop oil pressure, but not alot. do you have a stock oil pump? cuz 55 psi doesn't sound that low.

 

I think that is too thick of an oil. You do realize multi-weight oils (10w-60) get thicker when they warm up. It starts as a 10w(thinner) when cold and goes to a 60w(thicker) when at operating temp.

Also was this verified by something other then the factory oil pressure sender? Like a mechanical gauge to make sure the sender is not faulty.

Mike

 

there is a TSB on the oil pump bypass. Since the truck is modified and not under warranty, you might want to just go ahead and change out the oil pump.

had this happen on a 2010 Camaro, that is how I found the TSB.

 

its fine until 6000+ rpm , u think thinner oil could be the solution?

 

hell it's worth a try...

 

I would get that oil out of there,these engines clearances are not meant for 60wt oil.
With an oil that thick at normal operating temps can accually increase wear.This would have to be verified by doing a UOA.

 

I had a problem with my 5.3 swap and oil pressure and ended up being motor sludge and buildup making its way to the pickup at higher rpms..possibilitie depending on how the motor looks inside

 

Incorrect. It is a 10w when cold yes, but has the flow characteristics of a 60w when warm. It does not actually get thicker, but it resists flow just as a 60w oil would when at operating temp.

 

^^^ Correct