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Post by minitransformation on Aug 28, 2018 20:11:05 GMT
Enjoying my rebuilt 998cc Auto Mini. Did very little to the low mileage engine but am concerned about oil pressure. I have a gauge fitted and when first started it shows 50 - 60 PSI.
When driving (and on corners) the oil pressure dips. On a level road at about 40mph in top gear the oil pressure is showing about 25PSI - is this too low? Is it time to change the oil pump or are there other possible causes? Thanks.
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Post by richard1 on Aug 28, 2018 21:42:45 GMT
Tarija and Santa Cruz, Bolivia
First I would verify the gauge.
If it is right, it indicates either a worn or poorly assembled oil pump, or worn bearings.
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Post by jockduck on Aug 29, 2018 11:13:32 GMT
Yes 25 psi hot engine at highway speeds is too low, should be 50-60 psi, lots of possible candidates, oil pressure relief valve, valve block, internal leakage, It would be interesting to test the transmission oil pressure to see if it is correct, Oil pump wear is unlikely. Jock
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Post by richard1 on Aug 30, 2018 12:47:33 GMT
Tarija and Santa Cruz, Bolivia I forgot when I answered that on these we have the easy to damage relief valve, and a way to check the pump. Pull the plug at the top of the filter housing and connect a pressure gauge that will go up to 200 psi or so. The manual has the specs, but as I remember you need about 125 psi in Drive and 175 psi in Reverse. If you have that, your pump is good. Then check the relief valve to see if it is sticking open or opens to early.
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Post by notamini on Aug 30, 2018 18:06:26 GMT
Do you know if your gauge is connected for engine or transmission pressure? My engine pressures are better than this. Hot in idle is 45psi and at 50mph it is about 70psi. Cold in idle is about 75psi. Your transmission is even higher. Can you post a photo to show the engine connection?
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Post by minitransformation on Aug 30, 2018 19:49:13 GMT
Thanks for replies. Gauge is fitted on a T piece to the oil light pressure switch hole on the front of the engine. When the gauge dips the light flashes too momentarily.
Will check the transmission pressure and the relief valve next.
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Post by richard1 on Sept 9, 2018 18:54:46 GMT
Tarija and Santa Cruz, Bolivia
My gauge was connected to check the pressure before the relief valve. Connected directly to the port on the filter head.
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Post by notamini on Sept 10, 2018 15:26:15 GMT
What is it reading placed there, Richard?
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Post by richard1 on Sept 23, 2018 17:37:54 GMT
Tarija and Santa Cruz, Bolivia
I think it was on here that I got the minimum pressures. As I remember you need greater than 120 psi in forward gears and 175 psi in Reverse.
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Post by wimfournier on Sept 24, 2018 12:42:08 GMT
First of all, you have to be sure that the oil level is correct! When there is too little oil in the sump you won't get the correct readings. Because there gets about one liter oil in the torque converter when you are driving the car and because a great part of that oil runs out off the converter again when the engine is shut off, you have to follow the correct procedure to check the oil level. It goes this way: After driving the car for at least several miles stall the engine and wait a minute or two and than pull the dipstick and read the level. When you read the level on the dipstick after one hour, you will see the level is much higher. Because you tell us that the reading of the pressure drops when cornering, brings me to the assumption that you don't check the level at the correct way. There is too little oil in the sump. And than; you have to read the pressure from the special plug on the filter house foot. The readings that you get from the oil pressure light line is behind the oil pressure control valve of the gearbox itself. This reading doesn't tell you anything about the pressures in the automatic system of the box.
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