JimMueller

iTrader: (9)

I'm sure this has been covered elsewhere, but since Search is giving me a white screen ...

Before we removed the car from the lift, idle oil pressure was hovering right around 60psi. Took the car for it's maiden test drive today and oil pressure remained around low 40's while driving. I got off the interstate and had to wait for a stoplight. Oil pressure dropped to maybe 20-25psi as the RPM fell to idle speed.

I'm using a new Katech ported pump, a new pickup screen (which includes the o-ring), a long K&N filter and some generic 10W-30 dyno oil for break-in. I have about 20 miles on the new motor and haven't yet changed the oil & filter for the first time. Although I planned on doing it after the first 20 miles but didn't have time. I seem to recall seeing .001 stamped on the Clevite-H bearings, but I left a message for the shop who set the clearances, and left a PM for Katech as they are closed today.

Anything else I should be investigating?

mrr23

iTrader: (3)

if i remember correctly, lizzy told me the clearances are .0025" on the mains and rods. mine are the same amount.

heavy6.0

iTrader: (69)

exactly the same problem here on new motor. would also like some ideas. I have tore the front off the motor twice checking the o-ring etc. bad pump?

tilly

iTrader: (5)

Check the oil sending unit. Those things get broken quite easily when removing the intake. I had the same problem with my car and many friends had that same problem and fixed it when they replaced the sending unit. Its easier then messing around with the oil pump.

heavy6.0

iTrader: (69)

well I put a new one on when i did the motor swap and then another one a few days ago with no results. somethings junk and im begining to think it is the oil pump.

Krab

iTrader: (28)

I'd keep a very close eye on your oil pressure. As it is, I'd be worried and start tearing stuff down. First, I'd check the oil pump to make sure the O-ring is installed properly. Then, I'd check to make sure the bypass valve is not stuck open (you're going to have to disassemble the pump for that). Might seem like a bit of work, but better to be safe than sorry.

brians98ss

iTrader: (5)

I'm having a somewhat similiar problem here too with my new motor. The difference is that 90% of the time my hot idle pressure is in the mid to high 30s but every now and then it will be at 25#.

JimMueller

iTrader: (9)

I can see how the dang o-ring might be difficult to install with the motor in the car. But mine was on an engine stand... it isn't rocket science to attach the new pickup tube & o-ring to the oil pump and oil deflector tray.

Same thing for the oil pressure sending unit... that wasn't removed until after the long block had been dropped out the bottom of the car. And it was installed before we put the engine back in the car. But yes, I have broken the wire going to the sending unit in the past, and it merely reported zero oil pressure all the time. But I bought a new unit since then.

Anyone have a P/N for the sending unit?

Edit found it in this post: https://ls1tech.com/forums/showpost....62&postcount=6

JimMueller

iTrader: (9)

I'm starting to relax on the oil pressure. I wonder if the Caddy lifters affect the oil pressure as a result of the internal changes?

http://speedtalk.com/forum/viewtopic...w+oil+pressure

http://speedtalk.com/forum/viewtopic...essure&start=0

http://speedtalk.com/forum/viewtopic...t=oil+pressure

JimMueller

iTrader: (9)

Oh, what about the rear cover? We used a later model rear cover because it had more surface removed inside. I figured it must have been changed by GM for some reason.

JimMueller

iTrader: (9)

I found an old post which indicates Katech stopped shimming their oil pumps for higher pressure...

https://ls1tech.com/forums/generation-iii-internal-engine/67432-katech-oil-pump.html

And another post with a Katech exhibiting the same oil pressures I have...

https://ls1tech.com/forums/archive/i.../t-251796.html

Not that I really want to take apart the oil pump, but I wonder if my old SLP ported pump has a shim in it which is the correct size.

shoemike

iTrader: (25)

opening up your clearances will give you more flow and a little less PSI.
if you plug in a mechanical gauge you probably will find it is not quite that low.
the stock gauges don`t seem to be accurate (at least for me)
plug in a mechanical gauge and see if it is in line with the stock gauge.
i have the loosest ls1 ever built and have abused it daily and
have yet to have problems.

heavy6.0

iTrader: (69)

well that i sthe weird thing with my issue, i did plug a mechanical gauge into the little block above oil filter and it actually reads lower than the factory gauge... I'm really beginning to lean towards a messed up pump. I m really getting tired of buying oil and antifreeze just to try something else that doesnt work. I really think this pump has gone south, the motor is not making any unsual noise and the oil pressure dropped after running the new motor for about 300 miles..