Qfly

iTrader: (1)

A few days ago, I changed out the oil in my Camaro to 0w40 Mobil 1 and decided to take it for a test drive today to do some HP Tuner Logging. I also have a ported high pressure pump installed.

Before the swap, running 5w30, my oil pressure would come down to around 42 to 45 when warmed up. Driving around today, my oil pressure came down to 60 psi or so after the engine was warmed up. If I put my foot in it, the oil pressure was shooting to 75 psi or so.

Is the higher pressure with the 0w40 safe or do I need to drop back to a 30w oil?

Btw, I checked the oil dipstick and the oil level is showing 1/8" or so above the max fill line: never had issues with that oil level and 5w 30.

Thanks,

Sawacs

farmington

iTrader: (14)

heavier oil only costs you horsepower, UNLESS you have lots of bearing clearances and need the heavier oil.

Qfly

iTrader: (1)

Copy that. After a lot of reading and seeing that a few folks were running the 0w40 stuff, I figured I would give it a try.. oops..

5w30 is going back in tomorrow..

Thanks

JakeFusion

iTrader: (7)

What pump?

kinglt-1

iTrader: (26)

It says Melling HP in his sig.

Qfly

iTrader: (1)

Its a ported GM pump from back in 2002..

The parts in the sig have not been put on the car yet..

Changing back is not that big of a deal since I don't have to change out the oil filter.

JakeFusion

iTrader: (7)

Even Melling HP doesn't tell me... they have 4 pumps.

Try the thinner oil. Ported LS6 shouldn't be pushing the pressure that high when truly hot.

I run a ported LS4 and see hot idle at 40psi. But I have 16 little oil leaks called Johnson pressure fed oil lifters.

Qfly

iTrader: (1)

You just jogged my memory and I do believe it is a ported LS6 pump. Before the oil change tomorrow, I am going to take it for a longer drive (more than 10 or 15 minutes) and see what happens with the oil pressure.

JakeFusion

iTrader: (7)

Yeah, remember that just because coolant comes up to temp doesn't mean the oil comes up to temp. Drive it for 20 mins.

01ssreda4

iTrader: (96)

That pressure isnt gonna hurt anything, the pressure relief valve in the pump will bleed off anything higher.

kinglt-1

iTrader: (26)

^This.

pantera_efi

iTrader: (1)

Hi Fly, your oil pressure is fine as is your viscosity choice.
Mobil 1 was used by myself in many racing cars as this was the first non petro oil.

ONE guess for the low oil pressure is the HP tuning method you have stated.
There is a chance that you may have diluted your oil with fuel.

I would keep the higher temperature range oil in the engine, get your tuning correct.

Lance

Qfly

iTrader: (1)

So the needle hitting the 75 PSI mark under heavy throttle and high rpm's is okay?

I just want to make sure as this is my baby

Thanks!

Shawn

RockinWs6

How accurate is you oil pressure gauge? Of course heavier oil will show higher readings on the gauge but higher is ALWAYS better. I wouldn't worry until it gets over the 80 psi mark.

redtan

iTrader: (5)

There are some benefits to running heavier oil, even if you don't have the bearing clearances. Sometimes those outweigh the slight loss in HP.

That's not necessarily true. Volume is key, not pressure. If you get foreign materials stuck in the oil galleys it's gonna increase your pressure but starve your bearings of oil...that's not a good thing. I'd rather have 20psi with good flow to all the moving parts rather than 60psi but barely any flow because there's a major blockage.

ImprovedRacing

You mentioned it was a high pressure pump. Does it have a 75 PSI spring? I believe the stock spring is 60 PSI. If you have a 75 PSI spring then it's normal for it to top out at 75 PSI. If it's supposed to be lower, then your pressure relief valve could be stuck closed (though it's unlikely).

Since your pressures are a bit high I would switch back to 5w30. Unless you are tracking the car and experiencing very high oil temperatures, there is no reason to run the thicker oil. If pressures still seem high you could go further down to 0W30, which will be just slightly thinner and better for cold startups.

RockinWs6

Well of course that goes without saying....he didn't say he had noises or blockage etc....HIGHER IS ALWAYS BETTER

Qfly

iTrader: (1)

I was always under the impression that higher was better up to a certain point. At what point do you start blowing seals on a stock LS1?

I did go ahead and switch back to 5w30 which brought my oil pressure back to normal as far as my gauge readout went.

Thank you everyone for the information: great discussion.

Cheers!

kinglt-1

iTrader: (26)

You are not going to blow seals on a LS1 with any oil. There are posts over www.bobtheoilguy.com/forums where a member put 20w50 Vr1 oil in his stock ls1 then sent the oil in for analysis. The 20w50 showed less wear then 5w30. Thinner oil is used for better fuel economy, lower emissions, and more hp. I am not saying to run 20w50, but 0w40 is not hurting a damn thing. 40 weight synthetic is commonly used in the LS1 and has been discussed many times in the past.

Qfly

iTrader: (1)

Much appreciated for the information. I am rather ignorant about a lot of this stuff but LS1Tech always comes through with helping educate me

Out of curiosity, what kind of HP loss could occur from using a 40w vs 30w?

Since I have plenty of 0w40 left, I'll change over around mid summer and letter rip

Thanks again!