Oil pressure

[phenom_1819]

Okay, I know this issue has been talked to death. But I did some searches on the issue and want to make sure I understand right.

I had my sending unit replaced right when I bought my boat because I was having issues with the oil pressure indicator (don't remember if it was too high or too low).  I'm now having the low oil pressure alarm go off whenever I'm in idle.  I know this is normal -- but how normal: does EVERBODY'S boat do this?

The thing that weirds me out is this just started 2 weeks ago.  With the new CPU, the problem seemed fixed.

And, it sounds like my new computer is calibrated to read 10 psi less than what it actually is??  So my boat low oil pressure alarm goes off when the computer reads 5psi (does this mean really 15 psi?).  

Should I be worried? Would adding more oil to the engine fix the problem?  How do I know what kind of oil is in my engine (I don't even want to talk to SkiMasters to find out)?  Would running a slightly thicker oil fix the problem?  Even if its not a problem, the alarm drives me nuts.

Ski Masters in Seattle sucks ass now.  No problem saying it. They got a new service guy that is a complete prick and never even returns my calls -- even though he is taking care of some warranty parts for me.  Pisses me off.  I guarantee I'm not alone and almost want to talk to the owner, because I know he'd hate to hear that his service dude treats everybody like crap.

[toyotafreak]

Superfreak, you're superfreakin out. My oil pressure alarm has never gone off. Only alarms ever are low voltage and depth, and neither of those are audible.

Set your fluid leves to the dipsticks. If you're under 200 hours, you should have a Castrol or other non-synthetic 5W-30 oil. When you're over 200, you'd better have Mobil 1 oil, filter and ATF in there or I'm taking all your TRD stuff away.

If all of the above is good, get in touch with Jeff D.

Alarms going off too frequently are annoying and worse, they desensitize you to them - it's like they're crying wolf with your $16K engine.

You're still Rick James in my book. And I'm trying to get a boondoggle up to Bremerton so I can buy you some Chevron Super.

[phenom_1819]

Yeah, sorry about that.  R.J. was in a "funky" mood this morning.  As I started thinking about Ski Masters while posting, I started getting really pissed off.  I just miss the old service guy. He actually cared about customer service, and didn't mind helping out with little things (like decals...I can't seem to ever get the "TOYOTA" decals I want).   I had the boat on the water today and no alarms at all. Guessing it was just because I was running the boat so hard for the past couple weeks -- weather's been awesome up here.

But still, so with the modified computer unit, does it mean that even though my oil pressure is reading at 4-5 psi, it's actually at 14-15 psi?  That's how I understood the discussion -- the modified computers read 10 psi lower to eliminate the alarm at the top-end.  Somebody explain please...

Derek - now's the time to find a way to Seattle...  I'm moving to the east side of the mountains in mid-September.  In fact, I just bought my new house yesterday!  I'm pretty excited (glowing and perma-grinned actually...my first house).  Anyway, once I'm moved over there my boating time will be split between Seattle and Yakima...I'm leaving my boatlift on the folks' dock for when I'm in town.  Not a whole lot of wakeboarding close to Yakima.  About 2 hours from Seattle.  For the sake of sharing, here's a pic.  And yes, the boat will fit in the garage (the realtor thought it was funny that my number 1 criteria for a house was garage length and door height).

[toyotafreak]

Nice casa, especially for a first one. Funny how that all works nowadays, huh? Our first house was a brand new one, and our first boat was a pimped TOYOTA. Go figure. So are you saying there's no lakes near Yakima, or just no 'scene'?

Sorry, can't help with the oil pressure question.

[cyclone]

OIL PRESSURE SENDERS FOR TOYOTA BOATS

FACTS: Unreliable
Replacements read 10psi less than actual oil pressure to reduce "hi pressure" alarms.

Replace frequently or ignore it. It ticks me off when it makes my depth finder display disappear when I get a "low pressure" alarm.

Here are the specs for oil pressure as per the 1uz manual:
4.2psi @idle
43-85psi@3krpm

Measured with a mechanical gauge. I don't have the part number for the sending unit, but I'll get it.

I have heard that the engine develops over 110psi of oil pressure, to move the VVTI actuator that advances and retards cam timing based on load. Badass. The "strain gauge" type sending unit is not up to task, it is a rubber diaphragm with four resistors glued to it in a Wheatstone bridge configuration. Change in pressure distorts the diaphragm and bends the resistors. This changes resistance through a meter movement or equivalent display. I think (don't know for certain) that this type of measurement device is outdated in the automotive computerized world. I know that a mechanical device like this will wear out more quickly subject to more work, like tracking the changes in pressure for a four cam valve train on a high revving motor with 10.5/1 compression and huge mechanical loads. I think that we have a substandard part. We can certainly replace it with one that will work. I don't care if the gauge is accurate, just reliable and repeatable (precise, but not accurate, in control terms) and that it gives me a reading in between my alarm limits so I can read depth at idle (shallow) the only time it counts!  

If I find one with the same threads for a truck, 4.7 or whatever, I'll stick it on there and see what happens. Derek, whaddya got under your hood?

Pete

[toyotafreak]

Standard 4.7L. Has the same oil pressure behaviour as the boats - makes the uninitiated cringe when they see oil pressure near zero at idle. I've only got a Chiltons on the Sequoia, but it should have oil pressure specs. I'd assume the physical interface is the same. Will have to look.

[Epicrider]

I don't know if you agree with this,but I will confess it has worked for me....My service shop has told me that since these motors are water cooled,there is not much need for synthetic oil which I know lubricates better,but also cools the motor a little.
  My boat was getting the low oil press. alarm.He told me to switch to conventional motor oil(which is thicker) and the alarm should not go off like that.(which for me was at idle).I admit synthetic oil is better,hell, I use it in all my vehicles.But if you change your oil regularly,I can't see a problem with the other.

[toyotafreak]

Changing oil types (or preferably, changing the weight of the synthetic) might be an effective way to silence the alarm, but what other problems will it cause?

These engines are so 'tuned' that a change in viscosity has to risk some detrimental effects, right?