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I drove the car to Pismo Beach Coffee and Donuts this morning, about 100 miles round trip. I definitely have an oil pressure problem. After the engine gets to 200degrees, the oil pressure drops to about 30psi @2500-3500 rpm, and almost nothing at idle. The oil takes forever to get up to 180 degrees, so it’s doing good with the oil cooler not hooked up yet.
Either the oil is too light, 5W30, or my auto meter sending unit is bad, or the engine has a mechanical problem.
I changed the oil when I got back home to Castrol 20W50, and I’ll order a new sending unit from Summit in Monday. I’ll drive the car to church in the morning to see if the thicker oil fixes it. I hope it’s something simple, the dry sump oil pump is expensive.
HAPPY FATHERS DAY!
Could the overheat coming from the fact you plugged the heater core lines, with one being used as the temp sensor plug, as seen on post #193?
You have to allow water to flow there and if you don't use heater you need a u shaped bypass tube.
I didn't followed the whole thread so maybe you drilled out a passage from the inside of the water pump body, in that case discard what I said.
Could the overheat coming from the fact you plugged the heater core lines, with one being used as the temp sensor plug, as seen on post #193?
You have to allow water to flow there and if you don't use heater you need a u shaped bypass tube.
I didn't followed the whole thread so maybe you drilled out a passage from the inside of the water pump body, in that case discard what I said.
The thermostat is the factory standard 197 degree, and the engine runs mostly at 200degrees. Everyone says that is normal, but I’m ordering a 180 degree thermostat along with a new oil pressure sensor. The hottest the engine got to was 210 degrees. Overheating is not the problem. Low oil pressure is.
Your water and oil temp is fine for the LS7, just like in my 10C6Z06...water around 205-210, oil temp around 175-185 with the factory oil cooler. That oil pressure is not right, and as you said, either the gauge is wrong or you have a problem. My LS7 with Mobil1 0W-40 European Formula (I do not use 5W-30, ever, as specified by the factory) never shows less than 40 PSI under any condition. I will also use Castrol Edge 0W-40 European Formula only......European C6 Z06's came from the factory with Mobil 1 0W-40 European Formula only.
Last edited by jb78L-82; Jun 16, 2019 at 03:29 PM.
The Castrol 20w50 really seemed to help. I drove the car 15 miles to church today, and at 200 degrees coolant temp, I get 25psi at idle, and 50-75 psi cruising around at 2000 to 3000 rpm. Cold start, about 70 psi at idle. 200 degrees and 25 psi at idle.
Still way lower than my 6.0 GMC pickup and my 427 Convertible Corvette. One is a brand new Chevy built engine (427) and the truck is a 15 year old truck with 225,000 miles. This engine blew up in the 427, but I had the bock resleeved, honed, and inspected. It was built with standard size crank and rod bearings and the clearances checked out. Standard size LS7 crank and titanium rods. I disassembled the oil pump, cleaned and inspected it, it looked perfect. It only had 7000 miles on it. I re assembled it and used it. I hope that wasn't a bad decision. New oil pressure sensor is on the way.
Still way lower than my 6.0 GMC pickup and my 427 Convertible Corvette. One is a brand new Chevy built engine (427) and the truck is a 15 year old truck with 225,000 miles. This engine blew up in the 427, but I had the bock resleeved, honed, and inspected. It was built with standard size crank and rod bearings and the clearances checked out. Standard size LS7 crank and titanium rods. I disassembled the oil pump, cleaned and inspected it, it looked perfect. It only had 7000 miles on it. I re assembled it and used it. I hope that wasn't a bad decision. New oil pressure sensor is on the way.
Yes, my 2010 LS 7 C6Z06 with 5,000 miles on the motor shows 40 PSI at idle when hot with 0W-40......70-80 PSI under load at higher RPM
The thermostat is the factory standard 197 degree, and the engine runs mostly at 200degrees. Everyone says that is normal, but I’m ordering a 180 degree thermostat along with a new oil pressure sensor. The hottest the engine got to was 210 degrees. Overheating is not the problem. Low oil pressure is.
My ls3 runs 200-210 with ac on and 90+ outside idling in traffic. When i get some air going over the radiator it drops below 200 quickly. I'm running a 187 tstat. Ecm not tuned for it yet. Dewitts replacement radiator with ford focus fans. I think your temps are normal for the ls engines, i started a recent thread at ls1tech that made me feel better about it. My gauge reads 180 at the center so the 200-210 degrees still bugs me even though it's ok.
Yeah your oil pressure is a little concerning. Sounds like you got it under control. I can't help you much though since i went the ls3 route. Sorry man.
How much carb clearance does that hood give you? I need almost 6” from the drip rails to clear my supercharger but can’t find a reasonable option. Yours has the hump in the right spot though.
How much carb clearance does that hood give you? I need almost 6” from the drip rails to clear my supercharger but can’t find a reasonable option. Yours has the hump in the right spot though.
No clearance with a 3” air cleaner. I have a 2.5 element ordered. This hood gave me 3” additional clearance over the stock hood. The quality is excellent though.
During the research for parts for my 496 build (I know completely different engines) the speed/machine shop and almost everyone else I talked to advised me against running a high volume oil pump in my build.
They all stated that a high volume oil pump will have extremely low pressure at idle speeds and not recommended for street use.
Could it be that the oil pump you used is rated at a higher volume than you need and is causing the low oil pressure at idle?
During the research for parts for my 496 build (I know completely different engines) the speed/machine shop and almost everyone else I talked to advised me against running a high volume oil pump in my build.
They all stated that a high volume oil pump will have extremely low pressure at idle speeds and not recommended for street use.
Could it be that the oil pump you used is rated at a higher volume than you need and is causing the low oil pressure at idle?
I’m running the stock oil pump that came with the engine. I disassembled and cleaned it, and used it again. It only had 7000 miles on it. I used to run a big block oil pump in my 383 small block. 70 psi at idle! The engine leaked oil everywhere, and at high rpm driving, oil would make its way up the dipstick and the valve cover breather. I’d go thru oil like crazy too. So I know some of the drawbacks of a high volume, high pressure oil pump.
Thanks, any chance you can measure how tall the top of your air cleaner sits above the drip rails?
The front of my 3” air filter is 4” higher than the fender, the rear of the air filter 3” higher than the fender. It’s the most I could fit under the hood, but it rubbbed against the hood. So, I’m going with this 2 1/2” tall air cleaner. I hope 2.5” by 14” diameter flows enough for a 427 cubic inch engine.
I forgot I had one stashed. It’s from my Q jet days. The overall height is 3” again, but only the front of the air cleaner is rubbing against the hood. I put a strip of electrical tape to keep it quiet.
I forgot I had one stashed. It’s from my Q jet days. The overall height is 3” again, but only the front of the air cleaner is rubbing against the hood. I put a strip of electrical tape to keep it quiet.
Get a bigger hammer and see if you can bend the front end down a tad so it doesn't rub?? Or shave down some of the rubber on the air filter itself to gain 1/4"?
Last edited by davidbii; Jun 19, 2019 at 12:31 PM.
I forgot I had one stashed. It’s from my Q jet days. The overall height is 3” again, but only the front of the air cleaner is rubbing against the hood. I put a strip of electrical tape to keep it quiet.
