Like it says, i have 60 + psi of oil pressure all the time. I wasnt too concerned about the fact that the oil pressure has always been above 60 psi since day one but after checking the oil pressure gauge against a mechanical gauge and finding it to be accurate, well... now im concerned The engine is the GMGoodwrech LM1 350 and it makes alot more pressure then it should. At around 500 rpm it drops to around 45 psi, but 60 otherwise. Am i going to have to get another gmbadwench 350 under the warantee or did this thing get a HV oil pump from the factory or something? It runs good and the oil looks clean and free of metal chunks and what not but it seems like there is a restiction in the oil passages in the block. Am i screwed???

 

Just to give everyone else an idea, I have the same motor and I get about 25-30 psi cruising about 15psi idling.

 

ive got a 305 modded as per signature.....i run 40 at idle adn up to 80 under hard throttle

 

its not nessasarily a bad thing, what kind/weight oil are you running, i see over 60 on startup ( pegs stock gauge) it comes down once warm at idle, thats with 10/30 when i tried 20/50 it wouls stay at 60+ evertime but at a warm idle.

it could be a hv pump but i would guess your motor has nice tight clearances

 

the thing is that is a stock replacement and its not supposed to make that much pressure. I have the same engine mark has and im running 10-W30 and it makes way too much pressure. The pressure mark is getting is what im supposed to have. I doubt gm would put a high volume pump in the engine since the block isnt set up for high ammounts of oil flow and ive already logged around 6.5k on the motor. By now id expect to have the pressure come down. My fear is that there is a blockage in the block and the pump is just bypassing the oil that it cant get through. Who knows, maybe is still is really tight. Gm has a "tech line" regarding replacement parts and what not. Even though they're probably as usless as **** on a duck i might give them a try. I just want to know if i have a problem before its too late.

 

i don't think you do have a problem, i have similar pressure with a stock volume hp pump. you have to have a high pressure spring to make that pressure, its the only way, check the pn's on the two motors, make sure there the same

 

Me and mark both have the LM1 replacement motor. As far as i know, theyre idetical. Even though the engine doesnt show any signs of having an oiling problem, it is kind of discomforting to see the gauge shoot up to 60 psi and stay there. And its not unheard of for a gm engine to have oiling problems. Heh.. theres one sure fire way to find out. Leave it in there and see if it lasts.

 

havent driven my new police version lo5 much but i have 60+ at startup and about 45 at warm idle (only driven for about 20 min at once so far.)

i wouldnt be to worried about it unless your leaking because of the pressure...do we even get warrentys with our engine?!? they werent meant for our cars?!?

 

I had a 3 yr/50k mile warrant, I dont' think it's under warranty anymore.

 

lol... i havnt opened mine up yet but you bring up a good point. i forgot that mine is an 88 which effectivly voids the warrentee. I hear what you say about the high pressure when its new but mine never came down. Is it possible that the bearings and jurnals never wore and the clearences are that of when it was new? Theyre supposed to break in and the clearences are supposed to increase slightly. Ive been running regular ol' conventional oil since i got it w/ changes every 2k.

 

I have a pretty much stock '89 with 350 TPI. It has 87000 original miles on it and I run at 60+ psi and have for the past 7 yrs. My car came with a stock oil cooler. Could that cause the increase in psi?

 

Im starting to get the sinking feeling that i got a dud. I hear that gm is actually pretty cool about theyre warranties so i guess ill shoot over to the chevy dealer this fri. and get a second opinion and maybe another one of these fine quality mexican made 350's

 

did u check your oil ,like if there is coolant in there.when my car had the 305 tpi the intake leaked coolant causing the oil pressure to rise(really weird).even when the motor is hot and at idle generates 60 psi of oil pressure.try a new oil pump.or if your oil filter didnt blow up than just live with it.
dave

 

the oil is clean and free of coolant and such. just has abnormally high oil pressure. If its got a problem, then i want another one. After all, its their bad, not mine .

 

well.. i spoke to my roomate and friend who worked as a mechanic and he was intriugued so he asked someone else who is supposed to be the "gm dictionary" and he said that this engine came with a stock high pressure/volume pump and 35 at idle and 60 otherwise is normal for this engine, go figure. Saves me a trip to the dealer to get it checked out.

 

sound familiar??

 

its interesting thought taht there is such a large discrepency in pressures from two supposedly "identical" replacement motors. Mine was porbably manufactured around or before marks seeing how it was cast in late '99. Maybe they changed pumps in production. heh, maybe marks gauge is off.

 

My 350 runs at 60+ when first started, but its got 20W-50 oil in it with a high volume pump. It will work down to around 30 fully warmed up. Do you by some chance have a high volume pump?

 

is that 350 lm1 the replacement motor (p/n # 10067353) motor for $1,200? if it is than mine is right on line w/ marks and dimenteds. the high oil pressure thing is weird if you ask me. i wouldnt worry about it too much.

my opinion though

later

 

We have installed alot of GM crate engines for a School District's mini busses, man do they kill engines like nothing. Anyway, the avarage crate engine is high on the oil pressure, most are between 45-60 PSI. This is normal, the lowest reading Ive seen with a crate engine is 35PSI warm and even that went to 60PSI off idle. Theres noo need to worry unless theres excessive crank case pressure and that would result in burning alot of oil and smoke comming from the breathers.