BLDun

I took the intake off my LT1 and had it powdercoated along with some other things. When I reinstalled everything it went in easily enough but when I cranked it up the best oil pressure I could get was about 35 to 40 and the longer it ran the more it came down and settled at about 20. I had the same pressure reading on both the electrical and mechanical guage. I decided that I needed to pull the intake again and check everything so I just did that and found that everything looks fine to me. I checked the oil drive gear and no problems there. However, when I put it back together last time I bought some polished stainless steel intake bolts so the looked better and torqued them to the recommended specs. When I took them off this time they didn't hardly even seem tight. I have only put about 5 miles on the car since put the intake back on last time and had the oil pressure problem. I cranked it up in the garage about 3 times just to check the oil pressure so the bolts shouldn't need retorqued already. SO, here's my question. . .is it possible to have an effect on the oil pressure if the bolts weren't tightened down enough or would I have more problems with leaking? I had no oil leaks at all. I guess I might have to pull the pan and check the pump. Just seems odd to me that I always had great pressure until I replaced the intake and now this problem. Any suggestions???

Kevin Blown 95 TA

Your intake heats up and expands and might compress the gaskets enough to make the bolts seem loose so its a good idea to recheck the torque of the bolts after a couple heat cycles on any repair like that. It isnt related to oil pressure. If you have oil pressure lower than you were expecting, it might be related to your oil viscosity or bearing clearances or oil pump and releif spring. You might have less pressure when it heats up cause the oil is thinner. If you let a bunch of old gasket junk fall into the crank case from scraping the engine or something, then that might get on your pickup and cause a problem, but I am just guessing.

BLDun

The oil I"m using is the same as I was using before the change - Mobil 1 - so it shouldn't be a problem I wouldn't think. I just have a problem with coincidences so when the oil pressure took a dive and all I did was change the intake it makes it hard to believe that at just that precise moment the oil pump decided to take a blow as well. I was careful not to get and junk in the engine when I cleaned it but it is possible that it could have happened. How large is the screen on the oil pick up? i.e. if a small piece of RTV sealant got into it would it be enough to make the oil pressure drop??? I fishing here. I would like to find a way to fix it would dropping the pan but it isn't looking good at this point. Thanks

Pontiac_97

the screen on the oil pickup tube has about the same size holes as a screen for a window on a house. and a intake manifold wont have any effect on oil pressure

BLDun

OK, I'm not all that familiar with the path the oil travels in it's course through the engine. So is there a scenario in which a small piece of RTV could cause the pressure to drop? I'm not sure of the complete size of the screen but if a small piece got against it would it be enough to make the pressure drop? My mechanical guage and electric show the same pressure problem so it must be inside somewhere. Do you think I need to replace the pump?