blackz28x07

Some facts which might help solve the problem:
-1998 z28
-90,800 miles on it
-Oil pressure needle twitches when at an idle only
-when rpms go up so does the oil pressure(2k rpms i'm at about 40 psi, and when at WOT i go up to about 50 psi)
-oil used is valvoline full synthetic maxlife 5W30

I've had my 98 z28 for about 8 months now and my oil pressure problem has been doing it since i first got it. No problems have come from it(yet). When i first start my car with the engine cold the psi is about 45, after it warms up all the way after driving it will be around 25(i've heard from people that it's ok and not to worry about it). Well today as i'm driving in a lot of stopped traffic in 70 degree weather i see my temp gauge start to rise like normal to about 200 and then my oil pressure goes under 20!(about 17 psi). So i get home and turn the car off right away. I let it sit for about 2 hrs and go to turn it on again and the oil psi is about 30. Could my oil pressure sending unit be going out? I hope i won't need a new engine since i don't have enough money for a rebuild or swapping in another one.

Thanks for anyone who can help me out.

im2fast4u98z28

iTrader: (1)

my 98 did the same thing. when i pulled the manifold off the oil presuure sending unit had a hairline crack in it, not sure if that was the cause of the twitching but i put a new one. never had any more issues.

linebacker50

i got a 01 T/A and after the engine warms up at a red light or whatever the oil pressure gauge twitches also. i changed the oil and the twitching went away, and got alot better pressure. i used valvoline 5w-30 ( not synthetic ). but after about 2500 miles or so it started again. i would change the oil and see if that helps any, and make sure your not low on oil. good luck. if you find something that works, or something was wrong let me know.

blackz28x07

well the weird thing is it twitches the same day i change my oil. It stays steady when driving, just twitches when i'm at an idle.

69LT1Bird

iTrader: (1)

Get a new oil pressure sending unit. GM had issues for years with them.

blackz28x07

Someone else told me that in another person's thread, just wanted to get some reassurance.