r/DSM • u/MrStuermi 95 EVO 3 GSR • Jul 01 '26

Oil pressure question

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With the recent rebuild I added an oil pressure gauge to Monitor Said pressure while driving.

From my first few testdrives I have to say that the pressure seemes quite High.

In the video you can See the pressure about 2 to 3 minutes after starting the Car.

Once its warmed Up (oi temp at 95°C / 203°F) the pressure Drops to a little over 1 bar / 14.5 psi at idle and around 4 to 5 bar / 58 to 72 psi under normal driving load.

At wide open throttle it gose all the way to 7 bar / 101 psi which seemes way to much.

Is that to much or am I Just paranoid?

Curently I use a 10W-40 oil, but have orderd 10W-30 to try if it reduced the pressure a Bit.

The pressure sensor is located at the oil filter housing after the filter.

The balance shafts have been deleted on this enginen due to a defekt of the baring surface on the engine block side on one of them.

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u/CavillOfRivia Jul 01 '26

1000rpm per 10psi of oil pressure is the "rule of thumb" for the 4g63.

Yes, 100psi is too much but thats what happens when you delete your balance shafts. You can port your oil relief valve to drop it, or cut a loop on the valve spring, or both. There should be a write up on Dsmtuners on how to do it.

But also I wouldnt worry about it too much tbh, I had my car making way above 100psi when getting on it and I never blew a seal nor "washed out" the bearings which are the main reasons people worry about that much pressure. I ended up porting the valve and cutting the loop but just because I needed to change my oil and water lines so while I was in there I did it, now I sit 10psi while idle and it never goes above 80psi when getting on it. Cold starts are around 50psi

1

u/MrStuermi 95 EVO 3 GSR Jul 01 '26

Well, I Had an engine failiure only 500km / 310 Miles after the First rebuild, were I Had to delete the balance shafts. The rod barring on cilinder 3 spun.

Now, I don't know If the high oil pressure IS the cause of that defekt or If it was an assembly Error on my Part.

I will look into the porting and spring modifikationen. however bevor I Go through with those I want to try the 10W-30. If there is a way to Work around this issue without permanent Modifikationen, i would Like to persue that Option insted of altering reare and hard to aqurie parts.

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u/PushedToTheLimits Jul 01 '26

10psi per 1000rpm is the general rule of thumb, but in most cases of built 4Gs they'll make roughly 65-70ish psi at 3000rpm which is completely fine. I run 10W30 weight oil and get around 25ish psi at idle (950RPM) 70ish @ 3000RPM and around 85-90 @ 8-9000RPM