Oil Pressure

[manyfire]

Was running on the highway last night after the truck got up to temp and I was running about 75 i noticed the oil pressure fluctuating, when you accelerate/ or hill the pressure drops about 10psi and when you cruise at 55-65 the pressure is about 45 a little low but it still is jumping up and down one or two psi, I am thinking oil pump, there is just a couple of small drips under it, nothing bad enough to be the rear main. the oil pressure comes off the back of the motor by the dist.

[406shark]

When was the last time you changed your oil filter? Could be the the bypass in the filter?


Jeff

[s15stroker500hp]

is it an electric or manual oil pressure gauge, i had the same problem with mine and it was the sending unit for my electric gauge, could also be a wiring problem.

[manyfire]

changed the oil and filter last month, and it is a manual oil pressure gauge.

[oncearacer52]

Maybe oil pump relief valve. 45 lbs. is not low in my book. Should be no less than 15 lbs at idle and as long as the engine is not tightening up at idle you should be fine.

[manyfire]

not worried about the 45 lbs, just dont like the fluctuating pressure on acceleration, how do I fix that.

[oncearacer52]

If it is the oil pump relief spring you can change it out but I would have no idea which one. Probably change oil pumps. IF that is the problem. Good luck chasing it down.

[manyfire]

noticed a little oil under it when I got home today coming out of the i hate to say it, the flywheel cover, doesn't drip when it sits, kinda tells me that the rear main is leaking, also noticed some oil further back on the chasis from blowing under. am not loosing that much oil though, so where are these oil pump relief valves at? I am going to change out the oil filter just in case it is messing up, cheap fix. I need it to hold up fo a little over a month so I can put the exhaust on it, I just spent the weekend rebuilding the front end, when I had new tires put on he found a bad ball joint, everything was OEM so I replaced the ball joints and outer tie rod ends. i think I could have bought a new truck by now! What fun would that be?

[oncearacer52]

The relief valve is built into the oil pump. You have to take it out to change springs.

[manyfire]

if i am going to go through all that I may as well change the pump out, for my app I am thinking about a high volume standard pressure pump.

[manyfire]

just went out and looked under it, puddle about 3/4 the size of the diameter of a 5 gal bucket bottom, all out of the bottom of the flywheel cover, I take it there is no way to pull the rear main without pulling the motor? 87 1 piece seal. My wife is going to kill me, I have sank over 2K in this thing this year so far, still have to replace the exhaust, looks like the custom dash and guages I was going to make is gone this year!!!! Maybe it is the back of the oil pan, I really don't want to tear the whole front end off this thing again!

[Melonhead]

She needs to start paying your life insurance policy. LOL

The rear main seal can be done in the truck if you can remove the trans and drop the pan to replace the pan gasket. If you can't replace the gasket, then yes you have to pull the motor.

[manyfire]

thanks for the great news, looks like I will be pulling the motor,yea, anybody want to donate to the save manyfire fund? I take paypal, haha, just going to limit the driving until she goes to her parents in a little over a month.

[manyfire]

found the oil leak but it has nothing to do with the pressure, the rear valve cover bolt on the drivers side is broken off in the head, that sucks but can be repaired in the truck I just have to remove the brake booster. Any tips on how to get it out. Vortec heads

[manyfire]

its not comming from the bottom of the valve cover, but, from the loose bolt head, thinking about just putting a rubber plug in the hole until it starts leaking from the bottom of the cover. just a thought to keep from tearing it apart again, wait until the next rebuild to extract the bolt.

[ballom13]

Hey ive got a hight volume standard pressure pump and it works fine for me. that could very well be the problem..

[manyfire]

that is what I am going to put in it next month, at least I hope!