additive to boost oil pressure?

[KlimFord]

1991 Eddie Bauer, 208,000 miles on original engine. Oil pressure gauge has been going down over the years and now rides just above the L.

It runs smoothly, although understandably not the power it used to have.
1. Is it detrimental to run with oil pressure this low?
2. Is there an additive that would safely increase oil pressure (we used to use STP back in the 60's)
3. Would changing from 10W30 to a different oil be a good idea?

 

[boominXplorer]

Lucas oil stabilizer is the best thing you can add to keep a worn out motor running. It's a 1 qt bottle so just use it and 4qts of 10w30 next change.

 

[KlimFord]

Lucas oil stabilizer is the best thing you can add to keep a worn out motor running. It's a 1 qt bottle so just use it and 4qts of 10w30 next change.

Thanks. That's just what I'm looking for.

 

[gmbroy]

i must stress on keeping with the 10w-30 oil , if not the top of you engine will starve for oil . Try the lucas as boomin xplorer said . my oil guage stays on the low side also & has been like that for 100,000 miles . I keep the oil full & change every 3,000 miles like clockwork . be easy on the rpms & that motor should last you a long time . best of luck to you .

 

[KlimFord]

gmbroy, yes, 10W30 till the end. My dad ran a gas station and stressed changing oil every 2,000 miles whether it needed it or not, and that's what I've been doing with all my vehicles. I generally cruise at 62 mph (it seems to like it there) and rarely go over 70. As a side note, I was losing coolant and running rough and suspected a head gasket so I flushed the radiator and ran a bottle of Nonotechnology Permanent Head Gasket Repair in it for 600 miles then flushed again and filled with anti-freeze solution. Smoothed it out and coolant level stays full.

 

[TDG]

I vaguely recall the oil pressure gauge on these vehicles to be wired to a pressure switch that is either on / off (pressure / no pressure) akin to an idiot light of times past and not representative of actual engine oil pressure.

On my 93 the oil pressure gauge stays in one place and doesn't move with engine speed (normal operation would be ~15 psi at hot idle and significantly higher at cold idle / hot cruise) leading me to believe that it is on a switched circuit not a pressure transducer.

In your case the pressure switch may be failing leading to lower and lower readings. (Or I'm totally wrong)

 

[boominXplorer]

^This is correct. The oil pressure gauge works off a 5 psi switch and it does not sweep like the other gauges. If you have any tapping or knocking once the engine is warm then you need to thick up the oil for sure.

 

[2stroke]

Being a 91, I wouldn't be surprised if some had actual pressure gauges. 91's had all kinds of leftover parts., and you never know what you get. Does it seem to be quite a bit higher when cold, and changes with RPM? I converted my switch to an actual sender. Mine runs in about the same spot when hot, and has 285,000 miles on it. The gauges are pretty inaccurate, that could be 8 psi, or it could be 40. On mine, it is about 25 psi.

 

[Rhett]

Being a 91, I wouldn't be surprised if some had actual pressure gauges. 91's had all kinds of leftover parts., and you never know what you get. Does it seem to be quite a bit higher when cold, and changes with RPM? I converted my switch to an actual sender. Mine runs in about the same spot when hot, and has 285,000 miles on it. The gauges are pretty inaccurate, that could be 8 psi, or it could be 40. On mine, it is about 25 psi.

Did you run your sender to the stock gauge, or did you put in an aftermarket gauge?

 

[2stroke]

I ran it to the stock gauge, plugged in the same wire and everything. All you have to do is run a jumper around the resistor on the back of the gauge cluster. I do not have an actual gauge, but checked the gauge position with air pressure. 1/4 was about 25 psi, and just past half way was 60 psi, and that's where mine is when I drive it cold. Once warm, it settles into the 1/4 way driving hot, and barely drops at all during idle.