98pontam

iTrader: (4)

i have been watching my oil pressure ever since last summer when i noticed it dropping to 0-10psi fully warmed and at idle.. i though it was the oil pump but now i am thinking it could be a cooling problem...

took it out in early april this year when it was around 40-45f drove it around and everything seemed to be fine oil pressure at idle was right at 40psi.. coolant temp was right around 180-190f... fully warmed up and under WOT oil pressure went right up to 55-60psi and held there till i let off.. had it out a few times since with no problems...

then today (around 80f today and a little muggy) i took it out it was fine for a little while,coolant temp and pressure were fine at highway speeds 60-70mph and under WOT i was right at 60psi but once the car got warmed up and in stop and go traffic in this heat i noticed my coolant temp getting up to the 220-230f mark and as that temp rose my oil pressure would slowly drop to next to noting at idle.. took the car back home and put it in the garage only to hear my coolant boiling in the over flow tank..

so i guess the question is what are my options to deal with this?
flush my current cooling system and see it that helps?
better cooling system?
higher viscosity oil? like 15-50? ( running 10-30 right now)

i dont seem to remember having the oil pressure problem when i was using 15-40 a few years ago but the car was still having cooling problems on hot days.. just not as bad as it is now.. i am still using the stock T-stat and fans are running at full speed when it starts to heat up but are not really doing much of anything to keep it cool..

cantdrv65

iTrader: (3)

High coolant temps will thin the oil resulting in less pressure BUT it should not drop to 0 - 10 psi. You have some issues either with the engine or oil pump. My engine oil pressure will drop 7-10 psi in 100 degree texas heat and traffic and coolant temps of 220. It still maintains around 28psi at idle even then though.

Also an F-bod should not run nearly that hot!

tsench

iTrader: (15)

it happen to mine also but i took it out to the mecanic he told me it normal i live in texas so...it hot my oil pressure normal when the temp get up to 220

flatsix

Anything is possible. But if you narrow it down to the basics of oil,oil cooling, and coolant. you will probably find your answer. I could be wrong but a couple of things jump out to me. One. the engine has been use to thicker oils and is now currently running 10-30. Ls1's were meant like most all GM's to run 5-30 since the 80's. Gut feeling is pressure drops when oil gets thinner because pump has suffered, but more importantly your cam bearings over time have suffered. Mains and rods are possible. Two. you may have a lot of air in your cooling system if its been recently flushed/back flushed. even though this would give you definate temp spikes...a good oil system at least with a GM that is would give you the standard minium 20-25psi no matter how hot coolant temp is and roughly 10psi for every 1,000 rpm after idle to 6 grand. good luck. remember, you can't really hear cam bearings knock...but they can sure make you drop oil pressure.