sorry about the 4 previous post i was hitten enter on keyboard not tab, but anyway 65 122s....what is the yellow dash light onthe right hand side of the dash and what does it mean when it suddenly starts coming on intermittently.
thanks

I like to call it the "audible oil level indicator"... go around a corner too fast and the engine starts knocking. Time to pull over and add a quart or two.

Keep a VERY close eye on your oil level. Usually, if that light comes on at 60mph, you've done wasted your engine. An oil light ain't a warning device really... it just lets you know you've screwed up and need a new engine.

-Matt

What's the purpose of a oil pressure gauge? The previous owner installed one in my 122 and it reads around 2-3 psi (I think) when idling and then goes up slightly as the engine is revved. I really don't see the point of it.
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Tommy '64 122S

Let's hope that gauge is not accurate. A fresh B18/20 will run at least 40 psi at idle and around 70 when revved, and that's at full operating temperature with the oil thinned out.

I just checked it. You are right, it's reading 35-45 psi at idle (varies a bit) and around 65 when revved. The car was warmed up, but it was 20 degrees out so it may not have been real warm.
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Tommy '64 122S

> Let's hope that gauge is not accurate. A fresh B18/20 will run at least 40 psi at idle and around 70 when revved, and that's at full operating temperature with the oil thinned out.

Well, it's zero degrees here so maybe that's why it's off. :-)

When it warms up outside I'll take a closer look at it. I only glanced at it once and maybe the numbers are x10 or something...

Is it supposed to tell you when it's time to change the oil?
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Tommy '64 122S

Tommy, cold would make the gauge read higher. I really think your gauge is not working.

It isn't there to tell you to change the oil. If you have a warning light only, it only comes on when the pressure is dangerously low. Basically, it tells you a failure has already happened. A gauge lets you see that trouble is coming before damage happens, and it also tells you something about how much wear the engine bearings have. More wear = lower pressures (although that can have other causes as well).

I think the pressure relief spring/valve on my PV's oil pump must be stuck shut. I keep ruining oil pressure gauges when the pressure spikes over 100 psi (the gauge's upper limit) when I rev it much with the engine cool. So far it hasn't burst an oil filter so I'll just let it be for now.

I should get a higher capacity gauge just to see how high it is going. After one over-pressure cycle the gauges I've used just stay sprung at a max reading.

If with your oil burning you only top up the level instead of changing oil you will suffer dilution. This thins the oil and accelerates wear from lost lubricating quality. This happens especially when rings are worn and running a rich mixture.

Old b18's b20's commonly flicker their oil light at idle. My spare b20 runs quite well at low oil pressure. I put in a tube gauge and it was near 0 at idle, but up to 35 psi at highway speed. 20w50 oil made a big difference, especially right after the oil change. Now like 15 at idle and 40 at speed.
But I pulled it and want to at least replace bearing if possible. I't the smoothest b20 I ever had. It must be balanced or I am just lucky.

I have an electric gauge now and pickup from a b230. Have to get to Ace HW and find an 45 angled FPT fitting, I think, to get it into the t-fitting there already.

That's the oil pressure warning light. When it comes on, it means either:

1) The oil pressure is low. Bad news.

2) The oil pressure sender under the exhaust manifold is failing. Not so bad news.

3) The wire from the oil pressure sender to the light is shorting out to ground someplace. Easy fix -- be happy.

My oil light is working, i.e. it comes on at the ignition stage, but I am confused because it does not come on even when I've been known to drive with the oil below the MIN level on the dipstick. Should it come on under these circumstances and if yes, why isn't it?

Thanks

Tom

It can also mean you are low on oil which will cause it to flash at lower rpm's
-e

thanks, yeah i was just a little low on oil...funny cause even though the car burns about 1qt a month this is the first time i ever saw the little yellow light come on, i just figured it was broken! what was throwing me for a loop was that it was flashing till i got upto 60mph then it stayed steady...
thanks again

That sounds more like the wire under the hood grounding out on something. Either that or it was about 3 quarts low (and not even show up on the dipstick) and you've toasted the engine.

An older engine with some bearing wear will eventually start flickering the light at idle, but it should go off when the rpm's rise. Any engine with low oil levels will first start to show the light on hard left corners as the oil sloshes away from the left mounted oil pump (racing Volvo's often have baffles in the oil pan to prevent this). There is nothing that I can think of that would happen with the oil pressure that would cause flickering at low rpm's, and a steady light at higher ones.