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high oil pressure after porting oil relief valve

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jw_55_55

20+ Year Contributor
108
0
Oct 3, 2005
Silver Lake, Wisconsin
Was wondering how i could get higher oil pressure after porting the relief valve?? Had 100 psi by 4000 rpms and now have 100 psi at idle after doing the port job. Any ideas on what went wrong or how to fix this?? I need this car ready asap!!! thanks for the help in advance
 
Was wondering how i could get higher oil pressure after porting the relief valve?? Had 100 psi by 4000 rpms and now have 100 psi at idle after doing the port job. Any ideas on what went wrong or how to fix this?? I need this car ready asap!!! thanks for the help in advance

Only thing I can think of is perhaps a burr was left on the port job and is not allowing the oil bypass piston to move freely (stuck closed). That or might have messed up the wiring to your oil pressure gauge . . .
 
well plunger is free and still have higher oil pressure than before??? doesnt make sense to me since porting should only bring it down, not make it rise! Whats your thought on cutting the spring??
 
Did you use a gasket or RTV? If you used RTV too liberally, you could has possibly blocked the drain path.
 
nope i used a gasket! and still would like to know if cutting the spring a little bit would work??
 
Do you have balance shafts? When you port the hole it should look like a letter D when done. Is that what you did?
 
Is this a freshly rebuilt motor? If it is, it sounds like the crankshaft main bearings got put on backwards. The crankshaft oil gallery is the first one to get pressure from the pump.
If there was a restriction in there or the bearing halves were installed wrong you would have high oil pressure all the time.
Just a thought.
 
I would definitely not modify the spring . . . you have something else going on.

What does your oil pressure read when you turn the key to ON, but the engine is OFF?
 
ok well i just tried a bunch of different things... first off this a fresh re-build with no balance shafts!!! noticed after first startup that it said i have high oil pressure and didnt address it until everything else was right.

Now on to what i did tonight. I first made sure the little piston inside the oil relief was free( which it was) then decided to cut the spring some. No change then tried drilling a hold in the center of the piston so more oil could flow through still no change in pressure!!! so i definitly think something else is going on here!!! The only problem im having with all of this is that before i tried porting the relief valve my pressure was not nearly as high as it is now. B

Before 25 psi at idle and 100+ psi by 4k
Now 75 psi at idle and 100+ psi by 2k

So im basically i dont know where to go from here!
 
Well if this is a fresh build, the only thing I can think of is this:

You're going to need to buy a new spring and plunger for the bypass (obviously).

Next I would try and get a new oil pressure gauge (could probably borrow one from autozone or something), to make sure your oil pressure sending unit wasn't messed up during your port job.

If that verifies that you indeed do have high oil pressure at idle (with the engine fully warm), then you definitely have something in your oil system plugged up.

First thing I would check is replace the oil filter.

Most have bypass valves in them so when they become so clogged, your system will still get oil, but perhaps the one you have now has failed and is creating a lot of back-pressure.

Next I would have to say you're going to need to check to make sure you haven't spun a bearing (or make sure that they were installed properly to begin with).

But definitely check the easy stuff first. Confirm the high oil pressure with another gauge and change the oil filter.

Now as a last note- if you are getting 75psi when the motor is cold, you may not have anything to worry about. I ported my oil bypass some time ago and when cold, I have roughly 72psi. Once everything warms up and the oil is around 80C, I sit at about 22psi @ idle.
 
well when i initially start the motor it sits around 85 and then when warmed up goes down to 75. Im thinking something might of gotten clogged during porting( dont know what) all i can say is that i cleaned everything out very thoroughly and didnt have the oil filter on while doing this!! The only thing that gets me is that i had better pressure before the port...so something bad had to of happened.

- I have another plunger and spring thats why i was so ambitious with trying different things. But tomorrow i will definitly be going to autozone to see if i can use a different gauge and buy a new oil filter! then after that doesnt work...i think im calling the machine shop who did the motor build!
 
well i am going to try a different sender today and also get a different gauge to try out as well!! question is where can i get a oil filter bracket gasket today??? not any mitsubishi dealers close by
 
well i am going to try a different sender today and also get a different gauge to try out as well!! question is where can i get a oil filter bracket gasket today??? not any mitsubishi dealers close by

Buy some gasket material from autozone or similar place (should probably come in a blue roll and 1/8" thick or so).

Then just make one yourself . . . kind of a PITA . . . but if you have no other choice . . .
 
yea this is true...would be a pita but maybe worth it in the end...also i called ams and they said that the high oil pressure is normal and just to drive it. Im just worried about about blowing a front cover gasket or a turbo seal...will be at it again all night to see what i come up with.

Plans are new oil filter bracket, oil filter, plunger and spring. after that we will see what happens with the pressure!
 
yea this is true...would be a pita but maybe worth it in the end...also i called ams and they said that the high oil pressure is normal and just to drive it. Im just worried about about blowing a front cover gasket or a turbo seal...will be at it again all night to see what i come up with.

Plans are new oil filter bracket, oil filter, plunger and spring. after that we will see what happens with the pressure!

So long as you dont go much over 100psi you should be fine.
 
yea i have a reducer on the turbo since im feeding from the oil housing instead of the head. The only thing i think i should do differently there is run a -3AN line. My line is pretty big so that reducer is seeing maybe a little too much oil than it should be. More updates later today after i get off of work!!

Well i put a new oil filter bracket on and new oil filter and am back to the 25 psi at idle. Drove the car all day and it seemed fine. Changed my oil feed back to the head for the turbos sake!!(pain in the ass to make bigger threads there, but all worked out) I will keep this thread updated as i drive the car more. Im waiting to see if any leaks start to appear....thanks everyone for your help
 
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