l99 low oil pressure

[1JEWLDSSRS]

I have the Melling in my engine but not sure which one it is. Idling warm it sits at 32-35psi and when cruising at 2000rpm it sits at about 55ish. Cold start she is at 65 or so then drops back down when the oil is up to temp. 5w30 Mobil 1.

[morepowerjoe]

Originally Posted by gunchamp

L99 pump is higher than the LS3. Generally speaking, the L99 pump does not suffer from the LS3 issues. It has to have more due to the AFM system. I deleted my AFM when I built the top end and the factory pump has a pile of pressure with all that removed. I'm seeing roughly 30psi at idle as well when warm.

I don't know where you heard that the l99 uses a higher volume / pressure pump but that's bull because I looked up the part number for my 2012 SS2 l99 and the oem part number is 12612289. If you look at the melling M365 it says replaces oem number 12612289 which is a standard volume / pressure pump. As for everyone out there that believes that the l99 uses a higher volume / pressure oil pump you are wrong.

[morepowerjoe]

Originally Posted by 1JEWLDSSRS

I have the Melling in my engine but not sure which one it is. Idling warm it sits at 32-35psi and when cruising at 2000rpm it sits at about 55ish. Cold start she is at 65 or so then drops back down when the oil is up to temp. 5w30 Mobil 1.

Thank you for the numbers but I would need to know which oil pump you actually have to be of help.

[1JEWLDSSRS]

You're welcome, I will see if my shop remembers which one they installed.

[Aqua Blue RS/SS]

Originally Posted by morepowerjoe

I don't know where you heard that the l99 uses a higher volume / pressure pump but that's bull because I looked up the part number for my 2012 SS2 l99 and the oem part number is 12612289. If you look at the melling M365 it says replaces oem number 12612289 which is a standard volume / pressure pump. As for everyone out there that believes that the l99 uses a higher volume / pressure oil pump you are wrong.

Not calling you a liar, but asking a question here. If that’s the case than why are there so many fewer L99 failure threads vs. LS3 here. I know for a fact the pumps between the two are different however. (This is talking GM pumps, which as I understand come from melling, but not the melling brand if that makes sense) I don’t know other than GM part numbers what the different is between them. High volume on the L99 makes sense to me, because there’s a lot more being asked of the oiling system. Why do a lot of the performance shops not necessitate the replacement of the L99 pump in certain circumstances(mileage being a big one) because of its volume and reliability vs. the LS3 pump which they all seem to recommend. Again not calling you out or anything like that just asking questions.

[1JEWLDSSRS]

Originally Posted by morepowerjoe

Thank you for the numbers but I would need to know which oil pump you actually have to be of help.

I just chatted with my builder and they installed the 10295 in my engine. He also said that is the one they use to replace the LS3 ones. He also said that if you are an L99 you could use the 10296 and it would be the same as the stock L99 pump replacement. Hope this helps you out.

[morepowerjoe]

Originally Posted by Aqua Blue RS/SS

Not calling you a liar, but asking a question here. If that’s the case than why are there so many fewer L99 failure threads vs. LS3 here. I know for a fact the pumps between the two are different however. (This is talking GM pumps, which as I understand come from melling, but not the melling brand if that makes sense) I don’t know other than GM part numbers what the different is between them. High volume on the L99 makes sense to me, because there’s a lot more being asked of the oiling system. Why do a lot of the performance shops not necessitate the replacement of the L99 pump in certain circumstances(mileage being a big one) because of its volume and reliability vs. the LS3 pump which they all seem to recommend. Again not calling you out or anything like that just asking questions.

I'm not sure. All I know is when I called melling this morning the tech I spoke with said that the Vin #J which that is what I have the eight digit in the Vin # it shows him in his computer that it takes the M365 which is a standard volume / pressure oil pump. I have all data that shows me the part number for my l99 engine like I said is oem# 12612289 and if you look call any parts store they will tell you that is a standard pump.

[1JEWLDSSRS]

Joe, did you see my post above about the pump info you requested?? Post# 34..

[morepowerjoe]

Originally Posted by 1JEWLDSSRS

I just chatted with my builder and they installed the 10295 in my engine. He also said that is the one they use to replace the LS3 ones. He also said that if you are an L99 you could use the 10296 and it would be the same as the stock L99 pump replacement. Hope this helps you out.

Well that is a mystery to me because melling makes a 10296 that's a high volume/ pressure pump and they make a M295 for the ls3 that's a standard pump but I can't find a 10295. So I don't know. Knowing what I know now I would have put something better in because I do have a little bit of valve train noise and they actually sell a high mileage oil pump #M365HV that is 20% over the standard pump. I appreciate you taking the time to call your shop for me.

[morepowerjoe]

Ok I found the melling #10295 it is a high pressure oil pump that puts out 10% higher than stock so thank you 1JEWLDSSRS and TheFlyingBananaSS.

[1JEWLDSSRS]

Mystery solved?? I hope. You are welcome my friend!!! Glad we could help you out.. Good luck with everything!!

[Babobetoe]

My 2011 camaro 2ss idles warm at 25psi-30psi bone stock... on the pedal.. 40-50psi..Hard on the pedal 50-60psi.

L99, how ever I use a range AFM disabler so I run v8 all the time.

[morepowerjoe]

Originally Posted by Babobetoe

My 2011 camaro 2ss idles warm at 25psi-30psi bone stock... on the pedal.. 40-50psi..Hard on the pedal 50-60psi.

L99, how ever I use a range AFM disabler so I run v8 all the time.

Thanks for the info. But what does your car rpm idle at?

[PlymouthBarracuda]

Old topic but still I haven’t found the answer, what oil pressure should be at hot idle (Vin J) ?

Few years ago I saw somewhere on YouTube an old official video from GM, where they said that if the pressure is less than 26 PSI at idle, then this may be the cause / or consequence of improper operation of the AFM...

My 2011 SS L99 at hot idle at 250F show on gauge 15 psi, 240F = 18 psi, 230F 21 psi. Warm engine 26 psi, cruising at low speed 30 psi, cold start 50 psi. Using Range AFM disabler.

I started to use Lucas Heavy Duty Oil Stabilizer and idling pressure increased +5 psi.

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I also replaced my oil pump to MELLING M365.
Stock oil pump was 12710304 (but 12612289 and 12710304 are the same thing).

I'm currently considering the MELLING M365HV as larger displacement pump - 20% Additional Volume Over Stock Oil Pump.
Or MELLING 10355HV - High Volume and High Pressure +10 PSI Higher Pressure