Oil Pressure Loss on LS7 Dry Sump
09-13-2014, 12:48 PM
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Oil Pressure Loss on LS7 Dry Sump HELP!
Replaced the Oil Pressure Sending Unit and added an analog gauge as backup thinking it was the issue.....STILL LOOSING PRESSURE!
At idle and 195-200deg. Pressure is fine BUT when loading the engine at 3500-5500 rpm the pressure is lost... all of it! If I shut the engine off and wait 5-10min. I get my pressure back at idle.... totally crazy!!
I was told to add some oil and watch the level in the oil tank. WELL..WELL... When it drops pressure I noticed that there is no oil in the tank...Could it be a bad oil pump? Dipstick was dry (after waiting a couple of minutes)!!!! Where did the oil go?
Replaced the Oil Pressure Sending Unit and added an analog gauge as backup thinking it was the issue.....STILL LOOSING PRESSURE!
At idle and 195-200deg. Pressure is fine BUT when loading the engine at 3500-5500 rpm the pressure is lost... all of it! If I shut the engine off and wait 5-10min. I get my pressure back at idle.... totally crazy!!
I was told to add some oil and watch the level in the oil tank. WELL..WELL... When it drops pressure I noticed that there is no oil in the tank...Could it be a bad oil pump? Dipstick was dry (after waiting a couple of minutes)!!!! Where did the oil go?
09-13-2014, 04:46 PM
#2
Do you have a cooler inline? Sounds like you might not have enough total oil in the system. Also, if you pump is running too much volume, it could in theory be tossing so much up top that it doesn't have enough time to drain back down. Maybe cut the top off an old valve cover and run it and see how much is hanging around up there?
Just throwing stuff at the wall. Wish I had enough budget in my project to have dry-sump oiling issues.
Just throwing stuff at the wall. Wish I had enough budget in my project to have dry-sump oiling issues.
09-13-2014, 08:07 PM
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Do you have a cooler inline? Sounds like you might not have enough total oil in the system. Also, if you pump is running too much volume, it could in theory be tossing so much up top that it doesn't have enough time to drain back down. Maybe cut the top off an old valve cover and run it and see how much is hanging around up there?
Just throwing stuff at the wall. Wish I had enough budget in my project to have dry-sump oiling issues.
Just throwing stuff at the wall. Wish I had enough budget in my project to have dry-sump oiling issues.
I have an Oil Cooler as per OE C6Z. I did over-fill the oil tank for in order to keep better eye on level. What happened was the oil came to temp (195-210) and at high rpm I lost pressure ,,,I also noticed that when I lost pressure the Oil Tank dried up. However, after a couple of hours I walked out to look at the car and noticed that the oil returned to the oil tank. I think that there is a possibility that the return side (oil return to tank ) is not functioning properly. Otherwise, where did the oil disappear to ? and where did it return from after a period of time?
09-14-2014, 01:15 AM
#5
This might explain where the oil is going https://www.youtube.com/watch?v=8YzY8DhlnUw#t=160
Pay particular attention at about 2:10 into the video..... It will explain why the oil mysteriously reappears.
Pay particular attention at about 2:10 into the video..... It will explain why the oil mysteriously reappears.
09-14-2014, 08:14 AM
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09-14-2014, 08:19 AM
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This might explain where the oil is going https://www.youtube.com/watch?v=8YzY8DhlnUw#t=160
Pay particular attention at about 2:10 into the video..... It will explain why the oil mysteriously reappears.
Pay particular attention at about 2:10 into the video..... It will explain why the oil mysteriously reappears.
I'm aware of the video ad process. However, it explain the proper function NOT cause of failure or lack of pressure and lack of oil return to Oil Tank. Also, my oil returns ...only after shutting the engine off for a period of time. Im thinking the return side is constricted or plugged at times where the oil doesn't return freely. So, upon given rest time (without the oil pump circulating or pulling from oil tank) the oil returns from SOMEWHERE.
:-/
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09-14-2014, 10:28 AM
#8
I'm thinking the only way the oil can return over time after the car is shut off is by gravity. That video shows how the oil/air separation works inside the oil tank by using gravity to bring oil from the separator at the top to the holding area in the bottom of the tank. That could explain where the oil is sitting and returns from "SOMEWHERE"... It shouldn't take long unless it's clogged or the oil level is low.
You are right it still doesn't explain the loss of pressure. The oil pump has two stages pressure and return, You have pressure as long as you have oil available for the pump to pick up so the pressure side doesn't seem to be the issue. That only leaves the return side.
What year is the car? I read that 2006-08 holds 8qts and 2009+ holds 10 1/2qts.
When did the problem start? was it after an oil change or just out of the blue?
You are right it still doesn't explain the loss of pressure. The oil pump has two stages pressure and return, You have pressure as long as you have oil available for the pump to pick up so the pressure side doesn't seem to be the issue. That only leaves the return side.
What year is the car? I read that 2006-08 holds 8qts and 2009+ holds 10 1/2qts.
When did the problem start? was it after an oil change or just out of the blue?
09-14-2014, 10:41 AM
#9
I'm sure you know this but the manual also says to warm the engine the shut it off and wait at least 5 minutes before you check the level and not more than 20 minutes so the engine oil has time to settle.
How long are you having to wait before you see oil come back?
Sorry for asking so many questions but without being able to help hands on I can only ask questions instead of just checking myself.
How long are you having to wait before you see oil come back?
Sorry for asking so many questions but without being able to help hands on I can only ask questions instead of just checking myself.
09-14-2014, 10:44 AM
#10
I've been around sprint cars (Multi-stage systems) all my life and can tell you that dry sump systems are actually very simple but rely on proper level to work correctly. To little oil and you suck the system dry and lose pressure, To much oil and it will usually push oil out.
09-14-2014, 11:43 AM
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I've been around sprint cars (Multi-stage systems) all my life and can tell you that dry sump systems are actually very simple but rely on proper level to work correctly. To little oil and you suck the system dry and lose pressure, To much oil and it will usually push oil out.
Thank you for the continued effort in solving this riddle.
I drained the oil and cut open the oil filter...WELL...I noticed some dirt\grid like material...Also, there was glider like flakes in copper color. I Didn't like the latter so, I opened the oil tank and found the same in it.....THIS IS A NEW BUILT WITH NO MILES ON ENGINE...ONLY BREAK-IN, HEAT CYCLE AND DYNO TUNE.
I will post pictures in a sec....
09-14-2014, 12:40 PM
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Do you think the copper flakes are valve guides (bronze) debris? what else would be copper in color?
09-16-2014, 07:23 AM
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Motor is coming out for inspection as debris in oil filter and oil tank point to bearing issue. The Builder blames the Dealer for not cleaning the oil system properly after removing old blown engine and claiming that the Dealer should have replaced the oil cooler for sure and maybe even oil lines. The Dealer claims the Builder didn't assemble the new motor correctly....and the saga continues. I'm not a motor expert but the fact that the oil cooler was not changed (as it can not be truly be flushed of ALL debris) leads me to believe that improper cleaning took place.
Once the motor is our and we can inspect the bearings we will know more. I'm told if the bearing are not broken or spun than the debris was introduced via dirty oiling system however, if the bearings are spun or chipped than its a bearing failure that introduced the debris hence it will fall back on the engine builder.
I welcome feedback from those who has such service by Dealer and\or bearing information....
Once the motor is our and we can inspect the bearings we will know more. I'm told if the bearing are not broken or spun than the debris was introduced via dirty oiling system however, if the bearings are spun or chipped than its a bearing failure that introduced the debris hence it will fall back on the engine builder.
I welcome feedback from those who has such service by Dealer and\or bearing information....
09-16-2014, 10:31 AM
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At idle and 195-200deg. Pressure is fine BUT when loading the engine at 3500-5500 rpm the pressure is lost... all of it! If I shut the engine off and wait 5-10min. I get my pressure back at idle.... totally crazy!!
I was told to add some oil and watch the level in the oil tank. WELL..WELL... When it drops pressure I noticed that there is no oil in the tank...Could it be a bad oil pump? Dipstick was dry (after waiting a couple of minutes)!!!! Where did the oil go?"