What oil to use in 2005 6spd corvette

[Sweebation]

Hello, I am currently breaking in my engine. For the first start I used Driven BR30 break in oil. At first oil pressure was okay, a little lower than what I would consider normal however as the motor got to operating temperature the pressure dropped significantly, at idle it got to 7psi and I killed it, my builder advised me to continue break in as long as oil pressure continued to rise as the RPM’s did. So I continued break in. Oil pressure was a constant 39-43 between 2500-4000 rpm so I continued break in. When I pulled out that oil it came out watery so I suspect the car is running too hot for 5w-30 in hindsight. After that I put in Dino 5w-30 with ZDDP additive and began driving. It stayed at decent pressure the rest of that drive ~20 miles however the next drive as the car heated up oil temps got significantly lower. To the point it stayed around or below 1psi per 100 rpm. I am wondering if I should put in a heavier oil and if so what should I use?

 

[slacktide_bitog]

Is your new engine stock, or is it modified?

Didn't GM say to use 4718M back then? That was superseded by dexos1, but when the C8 came out, they switched to dexos2 and back-spec'd dexos2 to all Corvettes. Next year, dexos2 will be superseded by dexosR.

The C8 uses some version of M1 ESP. You can use that in your C6. The regular M1 0w40 is also popular in Corvettes.

PP Euro L is dexos2 and available at Walmart for a good price. These are slightly heavier than regular API/ILSAC 5w30

 

[JavierH19]

If you want to keep it thinner and free revving you can use castrol edge euro 5w-30 which is almost a 40 grade in viscosity. Has about 2000 ppm of phos and zddp combined and over 2800ppm of calcium. You could also use any 40 grade, I'm using quaker state euro 5w-40 in my stock l87 6.2 which is still under both factory warranties. Being in texas and me being me i'd use Delvac extreme 15w-40 but any 15w-40 will be great for it. If the rebuild was done well it shouldn't burn any oil.

 

[Sweebation]

Is your new engine stock, or is it modified?

Didn't GM say to use 4718M back then? That was superseded by dexos1, but when the C8 came out, they switched to dexos2 and back-spec'd dexos2 to all Corvettes. Next year, dexos2 will be superseded by dexosR.

The C8 uses some version of M1 ESP. You can use that in your C6. The regular M1 0w40 is also popular in Corvettes.

PP Euro L is dexos2 and available at Walmart for a good price. These are slightly heavier than regular API/ILSAC 5w30

Engine is a OE rebuild! Bottom end was done by machine shop and the top end was remanned OE heads. The only aftermarket parts are Melling oil and water pump. I have heard someone mention using the euro oil as well, would that be best instead of switching to a completely new weight, I don’t want to over compensate but I don’t know if it being a slightly heavier version of 5w-30 would make a big impact, thank you!

 

[Sweebation]

If you want to keep it thinner and free revving you can use castrol edge euro 5w-30 which is almost a 40 grade in viscosity. Has about 2000 ppm of phos and zddp combined and over 2800ppm of calcium. You could also use any 40 grade, I'm using quaker state euro 5w-40 in my stock l87 6.2 which is still under both factory warranties. Being in texas and me being me i'd use Delvac extreme 15w-40 but any 15w-40 will be great for it. If the rebuild was done well it shouldn't burn any oil.

Okay! I will most likely throw in one of these today, I am not too concerned about power or anything I just want to know that everything is properly lubricated, given that would you recommend one of those options over the other or does it not make a difference

 

[JavierH19]

Okay! I will most likely throw in one of these today, I am not too concerned about power or anything I just want to know that everything is properly lubricated, given that would you recommend one of those options over the other or does it not make a difference

Delvac extreme showed it having almost 2500ppm of phos and zddp and 2300 of calc and mag. So it's one of the most stout 15w-40's you can get locally at any wally. And even in the winter storms my trucks fired up like always with 15w-40. Texas isn't too cold thankfully.

 

[Sweebation]

Delvac extreme showed it having almost 2500ppm of phos and zddp and 2300 of calc and mag. So it's one of the most stout 15w-40's you can get locally at any wally.

Okay sounds good, I will look into picking some up today. I am hoping what I’m experiencing is due to oil being too thin and not a hardware issue

 

[Tharber]

You have a mechanical issue and not an oil issue. I'd pull the oil pump off and make sure you didn't tear the seal and or use the right seal. It is true the newer engines do not run with as high psi as the older SBC but your idle psi is way too low.
TH

 

[JavierH19]

Okay sounds good, I will look into picking some up today. I am hoping what I’m experiencing is due to oil being too thin and not a hardware issue

I'd let it break in good before doing both a compression test and checking consumption. Maybe 3k miles as that's where most of it occurs before it slows down a lot until about 25k or so where it usually ends. Hope that rebuild was done well, I'd hate the headache so fingers crossed. But what Melling pump did you use exactly. They have a standard and high pressure one. Some aftermarket pumps can also be lower pressure to increase performance at higher rpm's.

 

[PontiacHO]

You have a mechanical issue and not an oil issue. I'd pull the oil pump off and make sure you didn't tear the seal and or use the right seal. It is true the newer engines do not run with as high psi as the older SBC but your idle psi is way too low.
TH

That o-ring at the oil pump pickup tube has been a source of problems for years. Were the oil holes blocked that fed the AFM/DFM lifters?

 

[Sweebation]

I'd let it break in good before doing both a compression test and checking consumption. Maybe 3k miles as that's where most of it occurs before it slows down a lot until about 25k or so where it usually ends. Hope that rebuild was done well, I'd hate the headache so fingers crossed. But what Melling pump did you use exactly. They have a standard and high pressure one. Some aftermarket pumps can also be lower pressure to increase performance at higher rpm's.

It is a Melling 10295 high pressure standard volume. I used the included o-ring for the design of my pickup tube.

 

[JavierH19]

It is a Melling 10295 high pressure standard volume. I used the included o-ring for the design of my pickup tube.

Did you oil or grease the o ring and carefully install it. I've had instances of o rings shredding or twisting in cylinder rebuilds causing leakage.

 

[GMBoy]

I own a 2006 and a 2007 C6 - Mobil 1 (or your preferred Dexos Syn) in 5w/30 is fine and meets all the specs you need. I do not agree with running non approved and non spec'd oils such as 15w/40 and such as has been mentioned here. With that being said - something is wrong with your motor and sounds like the engine builder is blowing BS to you in waves! I do a lot of engines as well and EVERYONE starts up with full oil pressure at the 1st start. Running that engine to 3000 miles to "let it break in" is simply BS. Go back and have them FIX the mechanical issues on that fresh motor. Also don't run conventional oil - doesn't meet specs either.

 

[pbm]

If you want to keep it thinner and free revving you can use castrol edge euro 5w-30 which is almost a 40 grade in viscosity. Has about 2000 ppm of phos and zddp combined and over 2800ppm of calcium. You could also use any 40 grade, I'm using quaker state euro 5w-40 in my stock l87 6.2 which is still under both factory warranties. Being in texas and me being me i'd use Delvac extreme 15w-40 but any 15w-40 will be great for it. If the rebuild was done well it shouldn't burn any oil.

Good choice on the QS Euro 5w40 which is one of the best bargains out there on a fine product.

 

[Sweebation]

That o-ring at the oil pump pickup tube has been a source of problems for years. Were the oil holes blocked that fed the AFM/DFM lifters?

This engine does not have AFM/DOD

 

[Sweebation]

Did you oil or grease the o ring and carefully install it. I've had instances of o rings shredding or twisting in cylinder rebuilds causing leakage.

I used engine oil to lube the o-ring before install but i can definitely see the possibility of it being twisted. What would be the easiest way to diagnose/replace?

 

[Sweebation]

That o-ring at the oil pump pickup tube has been a source of problems for years. Were the oil holes blocked that fed the AFM/DFM lifters?

Never mind I just did some research, so from what I’ve seen the AFM towers still have oil flow on non AFM engines correct? And if so is this problem possible if orings were not installed correctly on the valley cover

 

[twX]

Some LS engines have had issues with the oil pump pressure relief valve sticking open. This results in low oil pressure at idle, when the valve should be fully closed, but normal pressure at higher rpm.

See this thread, and this one.

The issue is definitely mechanical and has nothing to do with the oil grade.