Still havin' oil press woes

[75MillerJet]

Okay i just took my boat out this last week and my oil pressure has seemed to have dropped since the last time i took it out. Last trip was low enough at 30-40 idle and down as much as 15-20 at 4,500+... last trip my throttle linkage was forcing me to idle around 1,200 and i fixed it before this last week to idle nice around 800rpm but now when it idles at that rpm the pressure sits at no more than 20psi. Now when i get it up to around 1,500rpm it pops up to about 30psi and then when i get on it some more and bring it up to 4,000 and up for more than 15-20 seconds its dropping dangerously low to around 10-15psi. This trip the weather was about 20 degrees hotter outside and my water temp was about 170-180 at running speeds and 190 at idle. I already know olds' reputation for oil problems but could my "new" oil pressure drop be from oil temperature being too high? Also i was told about tapping in some roll pins to the pushrods for restriction instead of pipe cleaners. Either one ok? And would jumping up to straight 50 or 60 weight oil be a good idea for pressure? Right now i'm running 10w30. Thanx for your help guys. I just wanna be worry free for the 4th! :mad:

[Duane HTP]

15W-50 Mobil One would help you, but it's not going to be a sure cure for the Olds oil pressure problems. It runs back to the pan a little faster than the normal oils. The oil you're running is too light though.

[SmokinLowriderSS]

Duane's right. A thicker oil may help some, that 10-30 is too thin, but I'm concerned as to why it's so low in the first place.
What is your cold idle oil pressure (while still getting off the trailer)?
What is the hot idle oil pressure (a half hour or more later)? 30-40psi?
10 to 15 psi cruising at 4,000 RPM?!!!!!
How large an oil pan is it running?
Try the heavier oil and see what happens.
I'm concerned about the lower end bearings and oil pump tho, especially if it's been seeing 15psi @ 4,000+ rpm. :cry: :cry: :cry:

[Old Guy]

I've been using Mobil 1 15-50 in all my boats (all Olds) for at least the past 20 years. Never had a problem, with and without oil coolers. I do recommend an oil cooler however.
old

[75MillerJet]

Duane's right. A thicker oil may help some, that 10-30 is too thin, but I'm concerned as to why it's so low in the first place.
What is your cold idle oil pressure (while still getting off the trailer)?
What is the hot idle oil pressure (a half hour or more later)? 30-40psi?
10 to 15 psi cruising at 4,000 RPM?!!!!!
How large an oil pan is it running?
Try the heavier oil and see what happens.
I'm concerned about the lower end bearings and oil pump tho, especially if it's been seeing 15psi @ 4,000+ rpm. :cry: :cry: :cry:
cold idle pressure about 25
hot idle pressure about 20
whenever i wanted to run it at more than 3500 rpm i would have to wait until the engine cooled off by letting it sit while i jumped in and cooled off... this is why it makes me think the decrease in pressure (decreased more than it already was :mad: ) is from the oil heating too much and thinning
i have a 10 qt pan

[396_WAYS_TO_SPIT]

Check your filter!!!!!!!!!!!!!!!!!!!!!!!!!!!!! If you see silicone or bearring fragments tear it down!!! I just put new bearrings in my BBC and found that the upper bearrings were worn! I had an oil pressure issue last year from silicone in the oil gallies! I got it all cleaned out but still had some in there. My oil pressure finally stopp waving at me and she ran fine. When I pulled her apart this year I noticed that the bearrings got worn due to low oil pressure! That will starve the bearrings at high rpm's. Spend the $$$ to pull it apart while it is running and save alot of $$$ in the long run!!
396

[SmokinLowriderSS]

That's my concern exactly. My hot oil pressure is only 23 psi on 10-50 syntech, but my cold is 55, as is anything above about 2,000 RPM, never wavers. Not after miles of WFO.
I'm afraid it's gonna start throwing rods one of these days soon if not caught.

[n8dawg]

In my olds I run straight 40wt. My pressure starts off at 50-60 psi then while cruising it will drop to 25-30 psi. When I make hard passes at WOT it will not drop past 25 psi. I've been running like this for 3 seasons with out any problems and you can ask anyone who's boated with me that I sometimes have a heavy foot. I'll drive it till it breaks then I'll put a chevy in it!

[kachina_labala]

Mechanical or electrical oil pressure guage? If its electrical get a mechanical one . They are not that expensive. I had some very strange oil pressure issues as well. It ended up to be the electrical sending unit. I was sweating bullets for a bit there.I now run both. I have the electrical one in the dash and If it acts up I can lift the engine cover and compare it to the mechanical one. Worth a check.

[SmokinLowriderSS]

I have a similar setup with a "spare" mech gauge under my hood, visible from the seats if the hood is open.

[75MillerJet]

I have a similar setup with a "spare" mech gauge under my hood, visible from the seats if the hood is open.
sweet cuz i actually just bought one 2 days ago and am installing it today so i'll see if there is a difference (cross fingers that the electrical one is acting up)

[Wet Dream]

Here's a copy of a PM that I sent to Flip about the oil pressure in my Olds, and nice .030 clearances. Scared the crap out of me, but got used to it.
"I was a little disappointed in my oil pressure that was 50 at cold idle, and 32 WOT hot. Hot idle...12. I thought it wouldn't last a weekend. It NEVER ticked the lifters from low oil pressure or anything. It ran like that for a couple of years. Still runs to this day."
I had to adjust my cold idle pressure from what I sent to him (42), I typed it wrong. I used Valvoline VR1 20-50. Cold idle was good, but each minute of run time would lower the pressure. Then it would hold that 32 psi all day long.

[75MillerJet]

Here's a copy of a PM that I sent to Flip about the oil pressure in my Olds, and nice .030 clearances. Scared the crap out of me, but got used to it.
"I was a little disappointed in my oil pressure that was 50 at cold idle, and 32 WOT hot. Hot idle...12. I thought it wouldn't last a weekend. It NEVER ticked the lifters from low oil pressure or anything. It ran like that for a couple of years. Still runs to this day."
I had to adjust my cold idle pressure from what I sent to him (42), I typed it wrong. I used Valvoline VR1 20-50. Cold idle was good, but each minute of run time would lower the pressure. Then it would hold that 32 psi all day long.
32 psi is no big deal right? i mean compared to what i'm getting right now anything is better but 32 is a safe pressure correct?

[75MillerJet]

Holy Sh**! I'm so stoked right now its incredible... so i installed that mechanical guage and at cold idle i'm getting 55-60 psi! That damn electronic guage is gettin' canned and i'm goin to the lake this weekend!

[n8dawg]

right on!!!!!!!!!!!! Go get that Miller wet!!! What lakes do you guys go to?

[75MillerJet]

right on!!!!!!!!!!!! Go get that Miller wet!!! What lakes do you guys go to?
we'll be going to nacimiento and staying at Oak Shores from sunday through wednesday... you goin out to san antonio or somewhere else?

[n8dawg]

We went to naci last weekend. The water is warm you guys should have a good time! Let us know how the Miller ran.

[75MillerJet]

We went to naci last weekend. The water is warm you guys should have a good time! Let us know how the Miller ran.
ah i just missed ya then... i was there from tuesday thru friday

[kachina_labala]

So whats the virdict?

[75MillerJet]

So whats the virdict?
cold idle = 50psi
hot idle = 40-45psi
3k rpm = 25 psi
4k and up = less than 20
so i pretty much just had it at 3,000 - 3,500 the whole trip and i was running 50w... o and my damn intake manifold was leaking so i got water in my oil and my bilge is filthy again... really starting to piss me off. I think i'm going to do the drain back lines and restrict the pushrods before the next trip.

[Oldsquirt]

cold idle = 50psi
hot idle = 40-45psi
3k rpm = 25 psi
4k and up = less than 20
so i pretty much just had it at 3,000 - 3,500 the whole trip and i was running 50w... o and my damn intake manifold was leaking so i got water in my oil and my bilge is filthy again... really starting to piss me off. I think i'm going to do the drain back lines and restrict the pushrods before the next trip.
Since you said previously that your oil pressure was fine last season, what did you change before taking it out this year that MIGHT be the cause?
The oil drainbacks and restrictors will only be of help if you are currently suffering from low oil supply in pan due to it all being pumped into the heads and draining back too slowly. This is really not likely at the RPMs you are talking about. 25 psi at only 3000rpm is already way too low.

[75MillerJet]

Since you said previously that your oil pressure was fine last season, what did you change before taking it out this year that MIGHT be the cause?
The oil drainbacks and restrictors will only be of help if you are currently suffering from low oil supply in pan due to it all being pumped into the heads and draining back too slowly. This is really not likely at the RPMs you are talking about. 25 psi at only 3000rpm is already way too low.
no it was never "fine"... it was just my guage that was telling me i was getting lower pressure than before. it also seems like i can't get up to 5k anymore where as i used to get about 5,200 rpm. Any thoughts?

[75MillerJet]

Would the slightest oil leak from the intake cause a drop in pressure at all? cuz i know for a fact that my intake leaked last trip... damn valley pans suck i've had more problems with those things than i can count so i finally smartened up and ordered a set of gaskets from summit and should be here tomorrow