383 low oil pressure problem

**fastrthanurs** · 05-03-2007, 08:50 AM

it's either that or the cam bearings. i'm leaning more towards on cam bearings since i have no noise from the mains. which doesnt mean anything either. probably do both main and cam. probably rods too while i'm in there.

**ls1maro99** · 05-03-2007, 11:29 PM

yea i would replace the rod and main bearings sence you have everything apart

**LETHALxLS1** · 05-05-2007, 09:35 PM

I would pull the motor and start over. Fk it.

**fastrthanurs** · 05-06-2007, 03:41 AM

thats what i'm doing. tired of the shit with someone else not knowing what to do. do it once and do it right.

**LETHALxLS1** · 05-06-2007, 09:02 AM

Cool-then you know what you got. Let us know how it turns out when you get done with it.

**edcmat-l1** · 05-07-2007, 08:32 AM

I'ts most likely the freeze plug in the front of the motor. If it were the plastic plug in the back, chances are it wouldnt even have this good of pressure. There's a small freeze plug in the front of the block, under the timing cover, kinda half behind the oil pump on the drivers side. An easy way to figure it out is to pull the pan, and remove the oil pressure sender and blow air into the motor thru the oil pressure sender port. You should get a strong stream of air from the spot of least restriction. HTH, Good luck
PS I wouldnt just rip it apart and start over, because if you've never built a LS motor, and you dont know what its missing, how do you know you wont end up in the same boat? Diagnose it properly, using a methodical approach.

**LETHALxLS1** · 05-07-2007, 08:46 AM

Originally Posted by fastrthanurs

but i can understand what he is talking about but it would cause premature ring and piston failure not pressure failure. for some reason when the engine gets hot the pressure is lost. all i can think is a bad cam bearing. maybe the redneck that put the engine together didnt lube the cam and the bearing seized or scarred up real bad. when the oil gets thin wallah! all i'm doing is guessing but whoever built the engine used waaayyyy too much gasket maker so i'm guessing they didnt know what they was doing! just a hunch tho.

Thats why I also think some half asser put this motor together. What real engine builder uses gobs of gasket seal??? Sounds like another Billy Bob special to me. Even if he does fix the oil pressure problem dude needs the notches in the block to properly lube the pistons-right? seems futile to me.

**edcmat-l1** · 05-07-2007, 09:15 AM

On any of the LS motors, you dont need hardly any sealer. Just a dab in the corners where the front and rear cover meet the block, and the pan gasket has little rubber areas for that. As for the notches in the block, as long as its about .100 minimum clearance for the rod, you should be fine. Dont think it has anything to do with the oil pressure. As for the cylinders getting lubed, as long as the crank is slingin oil, they're gettin lubed.

**fastrthanurs** · 05-08-2007, 03:43 AM

yea but i would rather just pull the motor and replace main, cam, and rod bearings that way i know they are new and check the tolerances to make sure that was even my problem. but i'm pretty sure it's the main or cam bearings causing the problem.

**fastrthanurs** · 06-06-2007, 06:37 AM

pulled the motor and havent gotten around to gauging the crank and stuff yet but the cam bearings look awful. it's looks as if they were installed backwards. just an update.

**LETHALxLS1** · 06-06-2007, 09:07 AM

Thats why IMO it made sense to tear the whole motor apart and start fresh. Apparently you thought the same. Whoever built your motor IMO is a novice who made mistakes. Good luck with it man.

**fastrthanurs** · 06-07-2007, 03:46 AM

yea i agree. i bought the car off mautofied.com and the person selling it misrepresented the car tremendously. but hey thats what happens. i'm just trying to get it running. i got some 75lb injectors if anyone knows anyone looking. 300 shipped.

**LETHALxLS1** · 06-07-2007, 04:54 PM

You might try putting the injectors in the "for sale" section (not being a smart ass just trying to be helpful) if you havent already. I didnt know they made injectors that big dayyyyyum!!! LOL

Good luck with the car bud!!

**edcmat-l1** · 06-07-2007, 05:03 PM

What the heck did it have 75s in it for? Plan on makin a grand at the wheels?

**fastrthanurs** · 06-08-2007, 03:39 AM

the car was supp built for nitrous and they guy at the dyno shop suggested 60 or 75 lb injectors. i bought them the same day i bought the oil pump thinking that was going to fix the problem. so now i have to do the bearings and dont need the injectors. not to mention i'm going to iraq july 29. and yea i already posted them in the for sale section.