airfedls1

I have a 1998 t/a with 134000 miles and I have noticed that when I start the car cold the oil pressure is about 55psi or 60psi but when I am in traffic it drops to about 30psi or 35psi. I give it a little gas and it goes passed 40psi or 45psi. I use 10/30 mobil 1 .Do I need to use a thicker oil or do I need a new oil pump. The car still runs awesome and doesnt burn oil or get hot . The weather is hot already in south texas so I don't know if that would have anything to do with it. Thanx for any imput. By the way this is my first post and yall have a great site!

Camaro_SS

iTrader: (1)

Nothing to worry about at all. Cold oil is "thicker" oil. As the engine and oil warm up, oil thins, and oil pressure drops. When you accelerate, crankase pressure increases, thereby increasing oil pressure. As long as you're not leaking or burning it, it's good to go!! I would however increase your oil rating to 10/40, to compensate for the hot summer Texas weather.

JEB Garner

I would continue to use the 10W-30 oil. I would not go up to another weight of oil. If the 10W-30 has served you well for 134,000 miles and the T/A doesn't use oil or very little, I would stick with what you know works for you and your car. It sounds as if the 10W-30 has done a good job for you and your car. Stick with the 10W-30.

staringback05

iTrader: (8)

im kinda in the same boat with you man. does the oil psi jiggle? or idle a little different? my 99 ta has 75k on it and lately the psi has dropped after it warms up or after i drive it on the highway. the normal idling psi is around 35-40, mine has dropped to 25-30 i use 10w 30 but im gettin the pump replaced and will prolly start using 10-40 instead. im not missing any oil and its not dirty or stinky.....so just becareful man, if it is your pump, esp. at that mileage it might decide to take a dump on you one day and say bye bye engine

airfedls1

thanks for your imput. I will start using 10/40 just to see if the psi changes, I even thought about getting a gauge pod with new gauges to see if it is just the gauge.Thanks guys.

staringback05

iTrader: (8)

ive been hearing alot about a oil sending unit up by the manifold, i wonder if this could be going bad or not and if so could this be cause our problems?

Camaro_SS

iTrader: (1)

Guys, oil pressure fluctuation is part of normal operation. Don't invent problems for yourselves. In 2001 the oil pump housing and ports were enlarged for better oil flow at speed, and are a direct bolt-on to 1999-2000 model year F-bods. Get one of those, or an electric oil pump if you're intent on changing out the pump.

MTN_Z

iTrader: (7)

Also, if you are planning on changing the pump yourself, make sure you buy a new oil pump pickup o-ring because if you don't replace it, you will still have oil pressure woes even after the new pump. I had that problem so I can vouch for it.

12Gauge

iTrader: (2)

I had been having the same situation happen until I changed to Mobil 1 5-40. Not that anything was wrong with the car either but it seemed to me that 35 or so psi was a bit low. I havent been able to find any more M1 5-40 locally but I think SpeedCenter in Pharr has Royal Purple 10-40. I think I'll give it a shot for my next oil change

staringback05

iTrader: (8)

lol fellas when the guage is rattling near the 20 mark something is wrong with my car....a car is supposed to idle around 40 give or take a few psi, its deff. not sposed to tick back and forth. when ur giving it gas its supposed to be between 40-60....gm manual....on my 99

airfedls1

I changed the oil this morning to a 10/40, it seems to be registering a little bit higher maybe five to seven pounds more. I will drive the car this weekend and we will see how it does. I hope it will turn out ok, if not it's time to call HPE.