oil pressure too high?

[bottledgt]

this is on a 1G turbo. when i got the car it had 150000 miles and a blown turbo, so i yanked it and rebuilt it. the internals looked pretty good for the mileage. the car had unusually high oil pressure when i brought it home. when i got it back together it was the same. it doesnt peg the gage, but it goes to the mark before the last one when you're on it and above half when at idle. i didnt replace the oil pump cause i tore it all apart and it looked brand new and all the clearances were right on. i got suspicious and hooked up a manual gage to it. at cold startup its on 75lbs. when it warms up it sits on 25-30, which is great. but if you rev it up around 3500 it pegs the 100 lb gage i have. i would think the relief valve should kick in way before that. i took it out and its just a big spring assembly and i cant see how it would be bad. so, any ideas on what is going on here

 

[bottledgt]

well i took out the oil filter bypass valve also, and theres not anything in there and nothing is stuck. can anyone tell me whether this is normal pressure, cause i dont think it should be anywhere near that high unless the relief isnt supposed to kick in un til after that. i need some help here cause im afraid to drive it like this. what got me looking in to this is the turbo leaks around the housing when you get on it, and i think its just this high pressure forcing it out cause ive had the turbo apart and all the clearances are great and was pretty clean and dry

 

[92awddsm]

when you pulled the pressure bypass vale, you say it was just a spring? There is also a piston in the hole. The spring holds tension on the piston and at higher pressure, the piston opens to bypass. If the piston is stuck, you will get high pressure readings. I would drive like that because the filter can blow up at that high of pressure.

 

[bottledgt]

yeah there is a plunger and the spring inside, then the cap. i thought it was stuck but when i took it out it is clean as a whistle,, which is why its stumping me on why the pressure is so high. i KNOW this is too much oil pressure, but i cant figure out where its coming from

 

[johnnytsi]

This is pretty normal oil pressure for a 1G. Mine runs 90ps at 3000 rpm when fully warm. During cold starts, it pegs my mechanical 100psi gauge.

John-

 

[bottledgt]

well if thats normal, ive never seen it. all the ones ive worked on seem to have low pressure not high. but if it is normal, wheres the oil from my turbo coming from? you say yours pegs the guage cold. well i can see that happening, but mine is peggin the guage when its hot and its at 100 lbs by 2000 rpm(i checked for sure).and it buries past what the guage can read by 2500, so i dont know how high its going by the time im at 6500

 

[johnnytsi]

hmmm, your's does sound a little on the high side. My engine is also a fresh rebuild (new oil pump) with under 7000 miles on it.

Did you check out the oil squirters when you had the block apart?

I built a 1G 4g63 a while back and blocked off the oil squirters, that engine had higher than normal oil pressure.

John-

 

[bottledgt]

yeah i blew them out and checked them, but the motor was really clean inside for 150000. it didnt really need gone through, but since the turbo was blowing so much oil through the motor i went ahead and did it, cause it is my g/f's car and i didnt want any problems later. anyway i reinstalled the suirters and torqued them.
ive decided that the pressure is probaly not too far off though, cause i checked her other car which is a 1g non turbo, and it has 150000 miles on it, and it still will go past 100 lbs at about 3500 hot.
this still leaves me with the turbo leak problem. it looks like it is leaking between the turbine side and the actual center housing where the 2 piece metal clamp is. i bought this turbo used, and was going to rebuild it cause ive done many before, but it looked really good inside, so i just cleaned it up and let it go. my theory is maybe its just too clean where the piston ring seals are and maybe it will carbon up and seal with a few miles. the motor only has about 30 miles on it so far. the plus is, the cold side of the turbo in the pressure side is clean and dry as a bone, so its not leaking on that side and burning it through the motor. and the car runs very strong and will blow the tires off all the way through 2nd and some in 3rd, so maybe it will just cure itself with breaking it in.