This has to be your first step. Going to a heavier oil will only mask a potential problem.
Oil Pressure Question
Thread Starter
Team Owner
Joined: Oct 2004
Posts: 35,065
Likes: 0
From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
Oil Pressure Question
OK, I'm this >< close to having everything perfect on my car.
One last little thing that is driving me nuts.
I had synthetic Quaker State in the motor, it was 10-30. When the car is cold the Oil Pressure is dead center of the gauge.
Once the oil temp warms up, the pressure drops pretty low on the gauge. to the point when at idle with the car in gear, the idiot light comes on and the needle drops into that little "danger zone" area.
I replaced it with Castrol Synthetic 5-40 because that's what the local store had.
Do I need to go to 20-50 to keep the oil pressure up? I have a temporary Fram filter on the car that I'll swap after a few hours of running, could it be the filter?
The bottom end has 30K miles and is in good shape.
The top end is brand new.
Any ideas?
One last little thing that is driving me nuts.
I had synthetic Quaker State in the motor, it was 10-30. When the car is cold the Oil Pressure is dead center of the gauge.
Once the oil temp warms up, the pressure drops pretty low on the gauge. to the point when at idle with the car in gear, the idiot light comes on and the needle drops into that little "danger zone" area.
I replaced it with Castrol Synthetic 5-40 because that's what the local store had.
Do I need to go to 20-50 to keep the oil pressure up? I have a temporary Fram filter on the car that I'll swap after a few hours of running, could it be the filter?
The bottom end has 30K miles and is in good shape.
The top end is brand new.
Any ideas?
Drifting
Joined: Sep 2003
Posts: 1,363
Likes: 7
From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
YES, filter can contribute to low oil pressure
I would not use an orange Fram filter even for a paper weight. The are known for backflow and pressure relief valve problems.
If the pressure relief valve is allowing all oil to bypass the filter element, it could contribute to your low oil pressure (not to mention defeating the whole purpose of an oil filter to boot!).
I have noticed a difference in oil pressure with Mobil-1 Oil filters (slightly lower as less restrictive yet better filter material), so it stands to reason that the filter can and does contribute to oil pressure.
Considering your goal (presume a engine rebuild), I would use the best oil filter, not the cheapest (since during breakin, you want to capture all those metal filings and contaminants).
Also, I thought synthetic oil was not to be used during initial engine breakdown. However, if it is now OK to use, I would think you want to stay to the same grade as will be used throughout the engines life.
If the pressure relief valve is allowing all oil to bypass the filter element, it could contribute to your low oil pressure (not to mention defeating the whole purpose of an oil filter to boot!).
I have noticed a difference in oil pressure with Mobil-1 Oil filters (slightly lower as less restrictive yet better filter material), so it stands to reason that the filter can and does contribute to oil pressure.
Considering your goal (presume a engine rebuild), I would use the best oil filter, not the cheapest (since during breakin, you want to capture all those metal filings and contaminants).
Also, I thought synthetic oil was not to be used during initial engine breakdown. However, if it is now OK to use, I would think you want to stay to the same grade as will be used throughout the engines life.
Racer
Joined: May 2006
Posts: 426
Likes: 16
From: Concord CA
depending on where you live (temp wise). I would think 10-30 would be good.. with 5-30 for the winter months.
I tried 20-50w before, it keeped the pressuer up higher, but it was not really needed (that is what I had on the shelf at the time. and used it.
I am back to 5-30w syn. for the the spring and may move up to 10-30 in a few months. I have noticed that I find more leaks with the Syn oil.
I tried 20-50w before, it keeped the pressuer up higher, but it was not really needed (that is what I had on the shelf at the time. and used it.
I am back to 5-30w syn. for the the spring and may move up to 10-30 in a few months. I have noticed that I find more leaks with the Syn oil.
Thread Starter
Team Owner
Joined: Oct 2004
Posts: 35,065
Likes: 0
From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
I would not use an orange Fram filter even for a paper weight. The are known for backflow and pressure relief valve problems.
If the pressure relief valve is allowing all oil to bypass the filter element, it could contribute to your low oil pressure (not to mention defeating the whole purpose of an oil filter to boot!).
I have noticed a difference in oil pressure with Mobil-1 Oil filters (slightly lower as less restrictive yet better filter material), so it stands to reason that the filter can and does contribute to oil pressure.
Considering your goal (presume a engine rebuild), I would use the best oil filter, not the cheapest (since during breakin, you want to capture all those metal filings and contaminants).
Also, I thought synthetic oil was not to be used during initial engine breakdown. However, if it is now OK to use, I would think you want to stay to the same grade as will be used throughout the engines life.
If the pressure relief valve is allowing all oil to bypass the filter element, it could contribute to your low oil pressure (not to mention defeating the whole purpose of an oil filter to boot!).
I have noticed a difference in oil pressure with Mobil-1 Oil filters (slightly lower as less restrictive yet better filter material), so it stands to reason that the filter can and does contribute to oil pressure.
Considering your goal (presume a engine rebuild), I would use the best oil filter, not the cheapest (since during breakin, you want to capture all those metal filings and contaminants).
Also, I thought synthetic oil was not to be used during initial engine breakdown. However, if it is now OK to use, I would think you want to stay to the same grade as will be used throughout the engines life.
Safety Car
Joined: Sep 2001
Posts: 4,164
Likes: 555
From: Glenbeulah Wi
The fram filter will not cause any pressure problems. There is a pressure bypass in the oil filter adapter that bypasses if the pressure difference exceeds 7 PSI. If the filter bypasses you will get unfiltered oil into the engine but you will not see a pressure drop.
If your pressure is really too low (check the pressure with mechanical gauge) you only have a few options. You can change the oil to a heavier weight (if the engine is in good shape and your clearances are large this can work). You can add a HV pump (again this is assuming the engine is in good shape), or you can rebuild the engine to reduce clearances.
If your pressure is really too low (check the pressure with mechanical gauge) you only have a few options. You can change the oil to a heavier weight (if the engine is in good shape and your clearances are large this can work). You can add a HV pump (again this is assuming the engine is in good shape), or you can rebuild the engine to reduce clearances.
Last edited by bjankuski; May 9, 2008 at 03:55 PM.
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Thread Starter
Team Owner
Joined: Oct 2004
Posts: 35,065
Likes: 0
From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
I changed the filter and the problem seems to be gone.
The pressure range is from, as best as I can tell, from 20-40 pounds. 20 at idle, maybe 25. Those gauges are just about as good as idiot lights.
Anyway, the Fram filter was about 3/4 inch longer than the Mobil 1 filter I had. I suspect that becuase the Fram filter was longer, it was close to the header causing the oil to heat up, thin out, and lose pressure and cause higher engine temps.
Not only did the pressure problem seem to go away, the engine temp, and the oil temp was also considerably cooler. I could not get it to heat up as much as yesterday.
The engine temps weren't crazy, they are just lower today. Yesterday the water temp was just above center, today just below center. The oil temp was down about 25% also.
The pressure range is from, as best as I can tell, from 20-40 pounds. 20 at idle, maybe 25. Those gauges are just about as good as idiot lights.
Anyway, the Fram filter was about 3/4 inch longer than the Mobil 1 filter I had. I suspect that becuase the Fram filter was longer, it was close to the header causing the oil to heat up, thin out, and lose pressure and cause higher engine temps.
Not only did the pressure problem seem to go away, the engine temp, and the oil temp was also considerably cooler. I could not get it to heat up as much as yesterday.
The engine temps weren't crazy, they are just lower today. Yesterday the water temp was just above center, today just below center. The oil temp was down about 25% also.
Drifting
Joined: Sep 2003
Posts: 1,363
Likes: 7
From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
I changed the filter and the problem seems to be gone.
The pressure range is from, as best as I can tell, from 20-40 pounds. 20 at idle, maybe 25. Those gauges are just about as good as idiot lights.
Anyway, the Fram filter was about 3/4 inch longer than the Mobil 1 filter I had. I suspect that becuase the Fram filter was longer, it was close to the header causing the oil to heat up, thin out, and lose pressure and cause higher engine temps.
Not only did the pressure problem seem to go away, the engine temp, and the oil temp was also considerably cooler. I could not get it to heat up as much as yesterday.
The engine temps weren't crazy, they are just lower today. Yesterday the water temp was just above center, today just below center. The oil temp was down about 25% also.
The pressure range is from, as best as I can tell, from 20-40 pounds. 20 at idle, maybe 25. Those gauges are just about as good as idiot lights.
Anyway, the Fram filter was about 3/4 inch longer than the Mobil 1 filter I had. I suspect that becuase the Fram filter was longer, it was close to the header causing the oil to heat up, thin out, and lose pressure and cause higher engine temps.
Not only did the pressure problem seem to go away, the engine temp, and the oil temp was also considerably cooler. I could not get it to heat up as much as yesterday.
The engine temps weren't crazy, they are just lower today. Yesterday the water temp was just above center, today just below center. The oil temp was down about 25% also.
One other possible reason it fixed it -- if the filter was getting hot enough to create bubbles in the oil, then that could explain everything as it would reduce the pressure and increase oil and coolant temps since the air bubbles would heat up faster than the oil.
