Erratic Oil Pressure Over 6k RPM

[NoHaveMSG]

So I noticed on my last track day my oil pressure would climb to almost 80, then after 6k would fall off and go all erratic bouncing between high 40's-mid 60's. It kind of freaked me out, so I started short shifting and backed it down. Anyone else with a gauge notice similar behavior? My oil was on the low end of the dipstick but I can't imagine that is enough to cause that. Oil temps never went beyond 220-230 range. Ambient temp was about 60, highest coolant temp I saw was 208. Pulling oil pressure from the factory sensor location on the front of the left side of the timing cover. Was using RP 5W-30. Going to 300V on my next oil change.

[humfrz]

Originally Posted by NoHaveMSG

So I noticed on my last track day my oil pressure would climb to almost 80, then after 6k would fall off and go all erratic bouncing between high 40's-mid 60's. It kind of freaked me out, so I started short shifting and backed it down. Anyone else with a gauge notice similar behavior? My oil was on the low end of the dipstick but I can't imagine that is enough to cause that. Oil temps never went beyond 220-230 range. Ambient temp was about 60, highest coolant temp I saw was 208. Pulling oil pressure from the factory sensor location on the front of the left side of the timing cover. Was using RP 5W-30. Going to 300V on my next oil change.

If you were on steep curves, maybe the oil pump couldn't find as much oil to grab hold of .....??


humfrz

[NoHaveMSG]

Originally Posted by humfrz

If you were on steep curves, maybe the oil pump couldn't find as much oil to grab hold of .....??


humfrz

It was doing it on the front straight when I see it most. I am thinking that the oil filter was bypassing at those RPM's causing the drop but I dunno. All of the longer turns were lefts and my forearm blocks my gauge on a left.

[Lunatic]

There have been reports of the oil pump cavatating above 7000 rpm.
What weight oil are you using? Most people on track go to 30 over 20 weight oil.
Also I would keep the oil level topped off.

[humfrz]

Originally Posted by NoHaveMSG

It was doing it on the front straight when I see it most. I am thinking that the oil filter was bypassing at those RPM's causing the drop but I dunno. All of the longer turns were lefts and my forearm blocks my gauge on a left.

Maybe the oil pressure gauge itself is just messing with you .....??

Maybe that's why most cars don't have oil pressure gauges to alarm people ..... just lights that come on, after the engine has blown up ......



humfrz

[humfrz]

Originally Posted by Lunatic

There have been reports of the oil pump cavatating above 7000 rpm.
What weight oil are you using? Most people on track go to 30 over 20 weight oil.
Also I would keep the oil level topped off.

I believe he said that he was using 5W-30.




humfrz

[why?]

top it off every time before you go on the track, our oiling system sucks for high rpms.

[wheelhaus]

If the sensor sends a voltage back as a signal then could it be possible the connection is flaky at certain voltages/resistances/vibration frequencies/position of the moon/etc?

If not, i agree keep the oil topped off at the full mark. Our little engines don’t hold much oil, so being nearly a quart low is a big quantity of the available volume.

[NoHaveMSG]

I will keep on eye on it and report back. I did do a 2nd gear pull on the street and noticed similar behavior but not as exaggerated. It just seemed to plateau and not really drop though not possible to replicate track temps on the street. Oil was topped off.

[Passion86]

Aright, I know I'm reviving an old thread, but I thought I better start here before creating a new one about the same issue. I installed an oil pressure gauge on a previous motor that blew, and put it on the new motor installed by warranty. I've recently started doing a lot more hwy cruising and noticed at 85mph or around 4600-4800 rpms my oil pressure would start to jump around erratically between 30-55 psi. If I backed off my speed to 83mph it was stable, and if I bumped it up to 90mph it again stabled out. I recently had my motor serviced for the valve spring recall, and asked him if he would check it out. He said he took the gear out of the front cover, cleaned everything up, and everything looked fine. Still jumps erratically at those speeds, so we determined it must be some kind of harmonic resonance and it starts to fluctuate like that. I still don't cruise at that speed though, as that's the speed I was going on the hwy when I blew the first motor. Which has had me thinking quite a bit about it.