Yes. Another low oil pressure thread. UPDATE 7/28
07-22-2011, 08:54 AM
#21
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Put a mechanical gauge on it. Or just keep driving it and stop worrying about it. The stock oil psi gauge is a joke at best in these cars.
But something that wasn't mentioned. Have you added any kind of ZDDP additive?
When i bought my TSP forged 347 I did this routine. Valvoline VR1 (racing) oil, half a bottle of GM EOS additive and delco filter. Did the proper break in of hot and cold cycle. Changed the oil again. Still using the Valvoline and GM EOS additive. Drove it 2500-3K. At 5K I changed it and switched to Mobil1. That car held fantastic oil psi. Crusing at hwy speeds it would hold 60-65. Even on Power Tour 2010 with the a/c blasting and coolant temps ready to boil over, it still held 50-57psi at idle. A conventional oil these days does not contain near the amounts of ZDDP that a "racing" oil does. Change the oil out to a racing oil, get a bottle of the EOS additive from the chevy house and see what that does for ya.
But something that wasn't mentioned. Have you added any kind of ZDDP additive?
When i bought my TSP forged 347 I did this routine. Valvoline VR1 (racing) oil, half a bottle of GM EOS additive and delco filter. Did the proper break in of hot and cold cycle. Changed the oil again. Still using the Valvoline and GM EOS additive. Drove it 2500-3K. At 5K I changed it and switched to Mobil1. That car held fantastic oil psi. Crusing at hwy speeds it would hold 60-65. Even on Power Tour 2010 with the a/c blasting and coolant temps ready to boil over, it still held 50-57psi at idle. A conventional oil these days does not contain near the amounts of ZDDP that a "racing" oil does. Change the oil out to a racing oil, get a bottle of the EOS additive from the chevy house and see what that does for ya.
07-22-2011, 07:04 PM
#23
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Well I was using Joe Gibbs break in oul which should have some of the highest amounts of zinc that goes in oil. i switched it out with some conventional 15w40 since we don't carry any racing oil at the shop.
The color was silver. It was a very very light metallic hue to it. and a few very very small shards. But isnt that normal on a fresh rebuild?
Here is a video if what happens. I would think if my oil pressure drops to 20psi when how that it wouldn't even make it to 70psi.
http://www.youtube.com/watch?v=8EuPwqoKgUE
The color was silver. It was a very very light metallic hue to it. and a few very very small shards. But isnt that normal on a fresh rebuild?
Here is a video if what happens. I would think if my oil pressure drops to 20psi when how that it wouldn't even make it to 70psi.
http://www.youtube.com/watch?v=8EuPwqoKgUE
07-22-2011, 07:34 PM
#24
My fresh build did the same thing, it started off kinda high after a few hundred miles the pressure was 15 at idle. I then did oil change to zr1 20 50 and it stays at 25 - 27. I've put another 3k miles on it with out issue. Oil pressure stays steady, I watch it like a hawk.
07-23-2011, 04:10 PM
#25
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The silver is piston skirt and things like that. It's copper color you have to worry about.
When the oil is its most hot and the engine has been running a long time and the idle oil pressure starts getting below 20, what is the pressure at 4K, 5Krpms ect?
When the oil is its most hot and the engine has been running a long time and the idle oil pressure starts getting below 20, what is the pressure at 4K, 5Krpms ect?
07-23-2011, 09:57 PM
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Today I cut open another filter that had a few miles on it. Look pretty good. Only thing in it was some black stuff that wasn't magnetic. The only thing black made of aluminum in there is the Mehling oil pump. My builder said that was common if I didn't get the pump centered exactly on the snout of the crank.
Since the .070 restrictor, oil pressure is much better. Not where I want it. Cruising at 40mph at 1500rpm it sits at 40psi. Im going to switch it out for some 20-50vr1 and see how she fairs then.
There was no copper flakes....yet. But if it was a bearing there would def. be copper in the filter.
I think the turbo just heats the **** out of the oil, thinning it out alot.
Since the .070 restrictor, oil pressure is much better. Not where I want it. Cruising at 40mph at 1500rpm it sits at 40psi. Im going to switch it out for some 20-50vr1 and see how she fairs then.
There was no copper flakes....yet. But if it was a bearing there would def. be copper in the filter.
I think the turbo just heats the **** out of the oil, thinning it out alot.
07-28-2011, 11:32 PM
#27
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Any other opinions? it seems half the people I talk to say its cool, go drive the ***** off it. Others are say no way! Tear that bitch apart!
The clearances on the rods are .0024 and the mains are .0023.
The clearances on the rods are .0024 and the mains are .0023.
07-29-2011, 12:18 AM
#30
I notice this when I got my car. It would idle cold at 50 and cruise at 1500 at 60 then once it warmed up it would go to 20-25 and 40-45 at cruise. I changed the oil to 20w-50 Amsoil High ZDDP oil and it is at 55 idle cold now and around 65 cruise and 30-35 idle hot and 50-55 cruise. Try that 20w-50 ZR1 or the Amsoil or any other high quality 20w-50 oil. The first number doesn't matter in your case since your cold pressure is fine the 2nd number is what's going to make a differnece for you since you are seeing low pressure when its hot.
I think you are right about the turbo heating the **** out of the oil and making the pressure drop.
I think you are right about the turbo heating the **** out of the oil and making the pressure drop.
07-29-2011, 01:00 AM
#34
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Not yet. I was pretty hesitant to waste the oil if it wasn't going to help much. I may just wind up saying **** it for right now because I want to drive it so badly. Then again, I don't really want to screw anything up. But a few other people are saying it cool just keep an eye on it. If it keeps getting lower you will need to do something about it.
07-29-2011, 04:31 AM
#36
I'm on a stock bottom end but I used to always have around 40-60 lbs when the oil was warmed up. Now that I have a front mount turbo I'm still using the same castrol german synthetic 0-30 and when it's not up to temp it is around 60lbs at 2000 rpm. After the coolant gets up to temp I would say it takes another 10 minutes before my oil pressure is down to 40 lbs cruising. When I get on it never goes above 50lbs anymore so I think turbo's heat the **** out of your oil. Maybe an external oil cooler would be a great investment.
07-29-2011, 11:40 AM
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Most would be .0015 to .002.....not over .002 because when it warms up the clearance increases even more.
your at .0023 increasing to say .0026
a .002 engine would increase to your .0023.....and maintain your cold start numbers.
I would run it till there is a reason to tear it apart. Worst case is new rods and crank, but either way your turning what you have, so you mine as well run it for awhile. If it breaks.....most likely itll make noise and your still turning the crank, probably about a 90% chance you get away with the same "repair" weather you do it now or later, which could be much much later.
07-29-2011, 12:29 PM
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Mains cause fluctuations in oil pressure from cold to operating temp. Your answer is right there.........................................0023 .
Most would be .0015 to .002.....not over .002 because when it warms up the clearance increases even more.
your at .0023 increasing to say .0026
a .002 engine would increase to your .0023.....and maintain your cold start numbers.
I would run it till there is a reason to tear it apart. Worst case is new rods and crank, but either way your turning what you have, so you mine as well run it for awhile. If it breaks.....most likely itll make noise and your still turning the crank, probably about a 90% chance you get away with the same "repair" weather you do it now or later, which could be much much later.
Most would be .0015 to .002.....not over .002 because when it warms up the clearance increases even more.
your at .0023 increasing to say .0026
a .002 engine would increase to your .0023.....and maintain your cold start numbers.
I would run it till there is a reason to tear it apart. Worst case is new rods and crank, but either way your turning what you have, so you mine as well run it for awhile. If it breaks.....most likely itll make noise and your still turning the crank, probably about a 90% chance you get away with the same "repair" weather you do it now or later, which could be much much later.
.0023 is loose!! I don't think it will harm anything, but you're going to have the pressure drop when it gets hot. For now, I would switch to the 20w-50 oil and just have fun with it, it should help out some.