90Formula305

I just got the car back after a year. I remember it running around 30-35 pounds at idle and 40-45 when cruising and under acceleration. Before my dad drove it down to Florida for me he had the oil changed and they put 10-40 in it. Now the most pressure it sees is 30 pounds. This being an older car should I just keep the heavier oil in it or switch it back to 5-30?

90Formula305

Bump

Atilla the Fun

How many miles did he put on it? If he put a ton of miles on it, your pressure could be down due to wear, and if so, then you don't want to use thinner oil. 30 psi is more than enough to be safe. If you're only getting 30 psi at redline, try moving up to 20W50 or a straight 30W.

90Formula305

The odometer froze at 57k miles the day I bought the car five years ago, so it's impossible to tell how many miles it has or has been driven during a certain time period.

gulf_coast_228

I've got a very similar problem on my 350. I'm not sure if it's something I did or a combination of things but my oil pressure took a dive after I changed my timing chain and refilled with a synthetic oil. it used to hang around the 40ish mark while driving and would dip to around the 15ish mark after a run on the interstate. Now it hangs around the 30 mark on the interstate and dips to the 10ish mark (almost in the red) when I stop at the off ramp red light. Any idea what I could have done, or what I can do to get my oil flowing better? Oh I've replaced the oil sending unit fairly recently since at that time it was reading 0.

90Formula305

I have a new sending unit as well. Mine did the same thing by reading zero all the time.

Rayzor32

iTrader: (1)

10-40 should be good, you want at least 10psi/1000rpm is the rule of thumb. Since you are in florida and its summer I would recommend some 20w50 castrol gtx.

90Formula305

I'm driving to Commiefornia in three weeks, should have mentioned that. Does royal purple make a 20-50?

Rayzor32

iTrader: (1)

Don't waste your money on royal purple just get regular oil.. your motor has already worn.. Is it at 30psi at idle? Or when you got WOT? When you go WOT it should shoot up to about 60.

90Formula305

It's only ever had royal purple or mobil1 and castrol synthetic in it, that's why I asked.


I didn't have the car for the past year and nobody ever put royal purple in it like I did, that's why it got switched up twice.

90Formula305

Ok, here's what I'm talking about. I seafoamed the car, changed the oil back to 5w30 and added a can of engine restore. This was a few hours later.

RED86Z28

I would not worry about it. Since its warm out use 20w50 if you dont feel comfortable with the 10w40s pressure.

UNCLE TOM

iTrader: (1)

o.k. , lots of response on this question . low indicated press. , more likely than not is an old/faulty oil press. sensor . 10w30 oil is fine if eng. has no knocks or funny noises . good flow/circulation is more important than high oil press. . too high oil press. can slow a stock eng. down . to those that say high oil press. is good , think about how an automatic tranny works . HIGH PRESSURE . good luck .