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Discussion Starter · #1 · (Edited)
In the ongoing saga of my Magnum...

So I recently swapped out the 5.7 on my RT for a new one. When I put on the intake manifold, it had blue gaskets already installed. The engine came with a set of gaskets with screens on the ports to prevent trash from getting into the engine. My mechanic friend said I don't have to install them because the intake manifold already had gaskets, and the screens would lower engine performance. Do I need to install the set of gaskets along with the ones that came already installed on the intake manifold?

Everything ran great for two weeks. But now, whenever I stop, the car would sputter and the check oil light would come on. This only happens after the car has warmed up to operating temperature and the idle dips below 1,000. I took it to a shop to have it diagnosed and they said it had low oil pressure, so I should change the oil pressure sensor, which was already brand new, or I may need a new oil pump, which is also a brand new Melling High-Performance pump. I opted first to switch the oil pressure sensor. I'll be doing that this weekend.

Something told me to check inside the intake manifold, so after removing the throttle body, I noticed a decent amount of oil pooling at the bottom. I know a little oil in there is typical, but this was maybe concerning. What's also concerning is that the oil was a dark brown, which is typical of used motor oil. However, the oil on the dipstick is still clear, like I just put it in. So, ultimately, I believe I may have received a faulty oil pump. I'm hoping it's just the OPS, or worst case scenario, I have to install the intake manifold gaskets along with the gaskets on the intake manifold. 馃
 

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This based on zero info submitted about engine type or size...

If this is really a new (rebuilt/ remanufactured), you need to quickly determine if the stalling is due to an actual oil pressure (oil pump) issue or a faulty oil pressure sending unit (OPSU). A new OPSU can / will demonstrate failures early in their service life (infant failure).Under normal serviceable conditions, spark / fuel will be cut when oil pressure falls below 4-5psi.

It the engine is a junkyard / used - then its is very likely near the end of its service life (<170,000Km). Note that oil pumps do not fail - unless they have ingested stuff that is (almost) as hard as the geroter interface.

Know nothing about intake gaskets assemblies with "screens." Either way - gimmicky and should be avoided. If 5.7; the OEM silicone gaskets are the only thing you should be using. 6.1; nothing but the OEM gaskets (avoid gimmicky / waste of money "thermal isolation gaskets - an ineffective waste of money).

The Melling unit meant as an OEM replacement is (way)more than enough. There is zero reasons to buy the same unit that offers three springs that alter relief pressure.



Side note: this came up today...again...someone who is being bamboozled on a truck forum into believing that a heavier viscosity (along with ridiculous oil additives and some sort of boutique oil) will somehow save their engine from the boogie monster and puppies from burning buildings (sad really - the BS never ends). Those who wrongly believe oil pressure is indicative of a healthy engine - really need to drop the touchie-feelie that - somehow - a higher idle pressure is somehow "better." It really is a silly idea to switch from the OEM 5W20 recommendation - which in fact the engine was designed for - to some heavier viscosity.
 

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Discussion Starter · #3 ·
This based on zero info submitted about engine type or size...

If this is really a new (rebuilt/ remanufactured), you need to quickly determine if the stalling is due to an actual oil pressure (oil pump) issue or a faulty oil pressure sending unit (OPSU). A new OPSU can / will demonstrate failures early in their service life (infant failure).Under normal serviceable conditions, spark / fuel will be cut when oil pressure falls below 4-5psi.

It the engine is a junkyard / used - then its is very likely near the end of its service life (<170,000Km). Note that oil pumps do not fail - unless they have ingested stuff that is (almost) as hard as the geroter interface.

Know nothing about intake gaskets assemblies with "screens." Either way - gimmicky and should be avoided. If 5.7; the OEM silicone gaskets are the only thing you should be using. 6.1; nothing but the OEM gaskets (avoid gimmicky / waste of money "thermal isolation gaskets - an ineffective waste of money).

The Melling unit meant as an OEM replacement is (way)more than enough. There is zero reasons to buy the same unit that offers three springs that alter relief pressure.



Side note: this came up today...again...someone who is being bamboozled on a truck forum into believing that a heavier viscosity (along with ridiculous oil additives and some sort of boutique oil) will somehow save their engine from the boogie monster and puppies from burning buildings (sad really - the BS never ends). Those who wrongly believe oil pressure is indicative of a healthy engine - really need to drop the touchie-feelie that - somehow - a higher idle pressure is somehow "better." It really is a silly idea to switch from the OEM 5W20 recommendation - which in fact the engine was designed for - to some heavier viscosity.
My bad. 5.7 Hemi on my 2005 RT. It's a new (refurbished) engine from Powertrain Products. I'm not switching oil types. I know better. 馃槈馃憤

A new OPSU can / will demonstrate failures early in their service life (infant failure).Under normal serviceable conditions, spark / fuel will be cut when oil pressure falls below 4-5psi.
Does this mean the failures will work themselves out?

Note that oil pumps do not fail - unless they have ingested stuff that is (almost) as hard as the geroter interface.
I'm praying this is true. Again, this is a brand new oil pump on a brand new engine, and I was extremely careful not to let anything get into the cylinders ports before installing the intake manifold.

I'll replace the OPSU tomorrow and report back. Thanks for the info. 馃槑馃憤
 

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*My bad. 5.7 Hemi on my 2005 RT. It's a new (refurbished) engine from Powertrain Products. I'm not switching oil types. I know better. 馃槈馃憤

Not aimed at you MM :^)

Its gets real tedious after a while -trying to explain why it bull**** because one has to get deep into how things actually work / operate - in order for the recipient to understand first - then get the ahah moment, then get pissed off cause they almost fell into acting on emotions...especially where there is zero evidence to back up the assertions (otherwise know as anecdotal BS) instead of facts and logic (called critical thinking).


*Does this mean the failures will work themselves out?

No, infant failure means the device has fallen outside of specification and will never recover. Oil sending units, similar to T-stats have early failure rates (over many years I've experienced both).


*I'm praying this is true. Again, this is a brand new oil pump on a brand new engine, and I was extremely careful not to let anything get into the cylinders ports before installing the intake manifold.

When I said ingested - I meant engine failure where metallic particulate of sufficient size and volume has compromised the gerotor and sidewall interfaces. The pump may still function, but with the increased clearancing, pressure drops exponentially.

*I'll replace the OPSU tomorrow and report back. Thanks for the info. 馃槑馃憤

I don't recommend folks throw replacement parts in an effort to solve issues - hoping it solves the issue(s) without first determining root-cause. Sending units are not returnable once taken out of the box. In simple terms, it would be prudent to remove the sending unit and replace with a mechanical gauge to actually determine hot idle psi.
 

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Is it possible the new to you intake manifold was already full of oil when you got it? That would explain the disparity between your fresh engine oil and the garbage in the intake.

edit: trust me, they are really hard to clean out fully due to the baffling inside.
 

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Actually super-easy to clean; take it to a manual car wash along with an environmentally friendly cleaner that is capable of cutting oil.
 
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