Well, flame me if i'm beating a dead horse, but I searched and wasn't able to find my answer. Today a test drove a 98 ls1 camaro with 100,000 miles and an auto tranny. One thing i noticed is at idle the oil pressure seems to be between about 15-20 psi which seems low and well crusing around 40 mph it was about 35 psi. I would like to know what the oil pressure should be. I know the low pressure could be caused by clearance in the bearings, bad sending unit, inaccurate guage etc.... What do you guys think? Thanks, Mitch

 

did u look at the oil and ask what weight oil was in the car. 5-30 wt will cause the oil pressure to drop a bit. how long was the car warmed up? ive never owned an ls motor so i could be wrong but i would be hesitant with this car. both my lt1s have held 20lbs at idle warmed up and 60lbs+ while driveing. the first one held at 50 to 65 all the time and started losing pressure at 180k.

 

Thanks for your reply. I did not check the weight of the oil. I checked the oil pressure after about a 2 or 3 minute ride (in 80 degree weather) down the road. For some reason i was concentrating to much on the oil pressure to look to see if the car was up to full operating temp (stupid me). It doesn't seem like the sending unit is bad because its not reading extremely low or extremely high pressure. Im extremely nervous that this engine is ready for a rebuild sometime soon down the road and i don't want to waste my money. It would be nice for someone with an LS1 to chime in and clue me in on what there engine oil pressure runs at. Thanks in advance for your replies, Mitch

 

My '99 a4 ls1 z28's oil pressure is around 20 when idleing(at stop sign/stop light) and around 35-40 when cruising at 40-45mph. Mine is my daily driver and also has 191,xxx miles on it.

Oh, I also use Pennzoil 10-w30.

 

I have not worked on LS1's but this falls under engine basics.

The min oil pressure you want is 10 psi per thousand RPMs. Anything less then that you could be damaging the motor. Assuming there is nothing wrong with the oil pump/oil pickup or filter once a motor gets down that low its time to freshen it up. But You do not want to make any decision on a engine based on the factory install gage. That gage might be right or not. If you have concerns about the oil pressure have it checked with a real pressure gage. I have replaced more inaccurate oil pressure sending units then I have seen cars with less then 10 PSI per 1000 RPMs.

 

I would say 15 PSI is about as low as you want to go. I see 18-22 PSI with a mild cam and a hungry turbo to feed and thats only after long runs.