What is the average oil pressure on a D24?
 

I just purchased a 3 bar oil pressure gauge. At idle I get about 2 to 2.5 bar, but anything above that, and the needle is pegged at 3 bar. Do I need to get the 5 bar guage for the D24?

If your goal is to see the true oil pressure at high rpm you'll need a gauge with greater range, but if your goal is to ensure that you have sufficient oil pressure to provide engine lubrication (which is usually a concern only at hot idle with worn bearings barring a sudden failure or oil loss) then the upper areas of the range are irrelevant.

To be honest, I've never quite understood the reason to have an oil pressure gauge since as long as the oil pressure is high enough to turn off the idiot light, then it's sufficiently high for proper lubrication. I have an audible buzzer wired to my idiot light so if I suddenly lose oil pressure I can shut the engine off before damage occurs. I doubt I'd notice the level on a gauge quickly enough after sudden catastrophic pressure loss (oil cooler failure, oil pan failure, pump failure, etc.).

Thanks for the reply!

I understand what your saying, I think I'll take your suggestion and wire in a buzzer.
I'm still curious about the oil pressure though. What is the "normal range" for this engine?

Bryan

I would have to disagree with the oil pressure light as a indication that everything is fine... Having a gauge is nice to see problems ahead of time, eg low oil pressure or strange fluctuations. The light comes on around 10lbs, which is sufficient for idle, but nothing above that. I think the gauge is a nice addition, however the light has its uses too, your not going to always be watching the gauge, and if pressure were to drop to nothing, you need a light, buzzer or whatever to get your attention. As for average oil pressure, my engine gets about 30 psi at idle, and ramps up to about 60 by about 1500 rpms or so, using 10w-30 oil at the moment.

Jason

I also installed a pressure-gauge and have some readings for you;

With the engine completely warmed up and 5W30 oil in my D24TIC i can read the rpm's from my pressure-gauge.

What are you saying????

If the engine is at 1000 rpm, the pressure is 1bar.
1500 rpm, 1,5 bar
2000 rpm, 2 bar

etc. etc. it's almost linear with each other.

The oil i used before was giving more pressure, it gave about 0,5 bar more added to each reading above.
But i prefer 5W30 full-synthetic otherwise my hydraulic valvelifter gets "pumped up" so constantly having opened one exhaust valve....

So if you have 2 bar idling with a warm engine that looks nice to me!What oil do you use?

Sure, there's theoretically failure modes that a buzzer on the pressure switch wouldn't notify you of but they're pretty darn unlikely, especially past the initial engine break in period. OTOH sudden loss of oil and/or coolant happen pretty often on D24s and probably sent the majority of the D24s made to the junkyard already and an oil pressure gauge isn't likely to be noticed quickly enough.

I have a 5 bar factory gauge I plan to install on mine eventually but I don't consider it very urgent... although I considered it pushing my luck waiting 3,000 miles after purchase before adding audible alarms to the coolant level, engine temp, and oil pressure. I guess it's a matter of personal preference but I would add the aforementioned alarms, and gauges on boost, EGT, oil temp, voltage, and calibrated engine temperature before I'd add an oil pressure gauge.

I wasn't saying at all that the light doesn't have its importance, in fact I would choose a light over a gauge if I could only have one or the other, to warn of a sudden failure. It sounded to me like the OP was interested in pressure to find the condition of the engine, which the light turning off doesn't really tell you much about. Its only saying its making above 10psi.

Jason

I've just purchased a used 5 bar gauge, to replace the 3 bar. I will take your guys advice and add audible alarms to the idiot lights.
This is on an N/A D24. I'm running 0W30 Mobil 1.

Are there two different senders for 3 and 5 bar gauges, and if so, how can you tell?

Thanks,
Bryan

Maybe someone will chime in that knows... Thats a volvo thing I'm not sure, if know one is sure here, check over on turbobricks.

Jason

[QUOTE=casioqv;4227] OTOH sudden loss of oil and/or coolant happen pretty often on D24s and probably sent the majority of the D24s made to the junkyard already and an oil pressure gauge isn't likely to be noticed quickly enough.[QUOTE]

Can you explain ?

never seen that