Help! Lost 10-15 lbs of oil pressure
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Help! Lost 10-15 lbs of oil pressure
My engine lost about 10-15 pounds of oil pressure. It used to make just under 40 at idle (hot) and a little over 40 at higher revs. Pressure really didn't go up much with revs.
Then it lost about 10-15 pounds at some point. Now at idle it makes 20-25 and never gets over 35 and that is after going to Mobil 1 15w50, which added about 5 pounds.
Is there something wrong with the bearings or do you think the pump might be going bad? It is a 99 LS1. Stroker, 6.1L, heads and cam. It has an oil cooler in the radiator but that was put on before the pressure problem. AFAIK the pump is stock 99LS1.
If it is the pump what would you recommend? LS6, LPE hi volume, Melling 296? I may be adding an Accusump to it also so there will be like 9-10 quarts of oil in the system.
Thanks,
George
Then it lost about 10-15 pounds at some point. Now at idle it makes 20-25 and never gets over 35 and that is after going to Mobil 1 15w50, which added about 5 pounds.
Is there something wrong with the bearings or do you think the pump might be going bad? It is a 99 LS1. Stroker, 6.1L, heads and cam. It has an oil cooler in the radiator but that was put on before the pressure problem. AFAIK the pump is stock 99LS1.
If it is the pump what would you recommend? LS6, LPE hi volume, Melling 296? I may be adding an Accusump to it also so there will be like 9-10 quarts of oil in the system.
Thanks,
George
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Idling at around 40 and staying at 40 at high rpms sounds strange first of all. Idling at around 25 and high rpms at 40 doesn't sound uncommon, especially with stock pump. 6 to 8 psi per 1000rpm is sufficient but not always desirable. May be worth taking it in and getting a "true" reading from a mechanical gauge. Just my opinion.
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Oil was changed when I went to the 15w-50. I'm positive that the guage is reading proper. I had the low pressure light come on slightly in the middle of the Carasel at Road America.
Which pump should I get?
Is it possible some bearing clearances have opened up? I can't think of anything else that causes a drop in OP.
Which pump should I get?
Is it possible some bearing clearances have opened up? I can't think of anything else that causes a drop in OP.
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I would say your oil pump is the problem, it seems alot of 1999-2000 models have this problem. I have a 1999 z28 and it was doing the exact same thing yours is. I installed the SLP pump when I did my heads and cam and now it idles cold at 65 lbs and 50 lbs hot . Just change the oil pump and you should be fine .
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I put the 15W 50 in to get more pressure. The car is roadraced and the 10w30 I used was too low when it got hot. I'll try a new pump before anything more dramatic.
So which pump? I saw Lingenfelter sells a high volume pump for $90. Seems decent. Any others? Like I said, the car has an oil cooler and will be getting an Accusump also so there will be almost 10 quarts in the system.
So which pump? I saw Lingenfelter sells a high volume pump for $90. Seems decent. Any others? Like I said, the car has an oil cooler and will be getting an Accusump also so there will be almost 10 quarts in the system.
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hahaha
well you raoad race it....sounds like you hasve lost a lil clearance throw in a new hv melling pump and the pressurev will return....and theres nothing wrong with 50 weight oil.....i run nothin but 40 in mine.....
oh and how many miles on the rotating assembly???
well you raoad race it....sounds like you hasve lost a lil clearance throw in a new hv melling pump and the pressurev will return....and theres nothing wrong with 50 weight oil.....i run nothin but 40 in mine.....
oh and how many miles on the rotating assembly???
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my 99 gave up the oil pump in 2001 so I swapped in a high pressure unit.
GMs have this issue but the General refused to recall.
...swap it or loose you engine...
GMs have this issue but the General refused to recall.
...swap it or loose you engine...
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My engine lost about 10-15 pounds of oil pressure. It used to make just under 40 at idle (hot) and a little over 40 at higher revs. Pressure really didn't go up much with revs.
Then it lost about 10-15 pounds at some point. Now at idle it makes 20-25 and never gets over 35 and that is after going to Mobil 1 15w50, which added about 5 pounds.
Is there something wrong with the bearings or do you think the pump might be going bad? It is a 99 LS1. Stroker, 6.1L, heads and cam. It has an oil cooler in the radiator but that was put on before the pressure problem. AFAIK the pump is stock 99LS1.
If it is the pump what would you recommend? LS6, LPE hi volume, Melling 296? I may be adding an Accusump to it also so there will be like 9-10 quarts of oil in the system.
Thanks,
George
Then it lost about 10-15 pounds at some point. Now at idle it makes 20-25 and never gets over 35 and that is after going to Mobil 1 15w50, which added about 5 pounds.
Is there something wrong with the bearings or do you think the pump might be going bad? It is a 99 LS1. Stroker, 6.1L, heads and cam. It has an oil cooler in the radiator but that was put on before the pressure problem. AFAIK the pump is stock 99LS1.
If it is the pump what would you recommend? LS6, LPE hi volume, Melling 296? I may be adding an Accusump to it also so there will be like 9-10 quarts of oil in the system.
Thanks,
George
and i installed a mechanical gauge in line,
and i have concluded that my stock sending unit/gauge is faulty.
i too road race a bit and have yet to spin a bearing.
change your sending unit first.
don`t bother changing your oil pump unless you
go with the melling hv 10296 or the gm hv 17801830