How Little Oil Is Too Little

I would say that there's a decent chance that you might be okay. You mention the OP gauge, but what was the dipstick showing when you finally switched off? I was told a long time ago that one should not rely on the OP gauge when it comes to low oil level.

Myself, I would have bought a couple of quarts of cheap oil at the gas station and stopped twice along the way to add some.

Anyhow, good luck. As I said, you might be okay...

 

The danger of this situation as I found out in an alfa 164 is the drop in presure usually means something bad has already happened, and when something carastrophic happens it is not linear with the presure guage

 

Where did you hear that driving with falling oil pressure is a good idea? It's one thing if you are flying a bombing mission in a B17 at 28,000 feet with nowhere to land. Quite another when your cars blood (a pretty good analogy) is pumping out as you drive. That 12 cylinder engine depends on that oil for lubrication and cooling (it is what keeps the hundreds of moving parts from scraping each other to death). The oil pressure gauge is only giving you a reading on the oil before it enters the system (the highest point) as it circulates down stream its relative pressure continues to decrease. If this value drops significantly you should STOP! In your example it seems that the oil level was the problem and you should have stopped and bought a case of oil and periodically filled it as you drove home.

It is possible that you "dodged a bullet" and nothing serious is hurt but you should carefully consider whether a 348 or 355 is a good choice for you.

With regard to the original problem and the repair your guy did. I'm curious about what had to come from UK, be modified, cost big $$ and ended up worse than before. Fixing leaky cooler hoses are not neurosurgery and could have been done with locally available parts.

I think you got "hosed"

 

The point being that both sufficient oil pressure AND volume are necessary. Like the previous poster noted, the OP gauge is reading pressure at its highest point and is not intended to be an indicator of whether the volume of oil is adequate. If you have plenty of oil, but no pressure (as with a pump failure), you're in trouble. Conversely, you'll likely get some kind of pressure reading with a very low oil level, but without an adequate volume of oil distributed throughout the motor, you're also at risk.

Do you remember whether your temperature gauge was reading warmer than normal?

 

Bill,

Given that you didn't have an abrupt and spectacular stoppage you're probably ok. I think the issue is not with the car being tempermental. It's just an old car with old lines and hoses. Any twenty or thirty year old piece of rubber is going to fail eventually. I don't think you'd find any less of a problem with a 72 Mercedes 280SL or like automobile.

 

woulda, shoulda, coulda...

In the future remember that a few quarts of oil is a lot less expensive than an engine.

 

One should know basics, like the cost of an engine rebuild. Armed with that info, one can then decide how far to drive with a major oil leak. Personally, I would have flat bedded the car to my house (or mechanic in your case).

These cars are not like an iron block pushrod Chevy. You can't run when overheating (you will warp the heads), you can't run with a blown head gasket, you can't run when oil or gasoline is leaking, you can't drive if you hear funny sounds from the engine. These cars will self destruct more often than not in a "limp home" situation. Get an AA card and a cell phone, and you can drive with peace of mind.

Ken

 

I've always said the 2 most important tools you can have in any old sports car are a cell phone and an american express card.

 

It's better to be lucky than good sometimes. Most of my mechanical knowledge has come from the Nike school of just doing it with a manual. Somtimes lessons are frustrating and expensive. I can assure you that every mechanic has made an expensive and with hindsite ignorant mistakes. People who are not mechanical that want to own any old car need to find a trustworthy mechanic. Hey you dodged a bullet congrats and you learned somthing... could be worse.
Rick

 

I had a mechanic to begin with and realized I could screw up my car for a lot less money than he did. I'm not a great mechanic myself but at least when I do things three times to get it right, I've learned something new. One thing I've developed is confidence that I can fix almost anything in the car myself.

Of course, for the most complex tasks like cam timing, a newbie might want to get a pro; you don't get a second chance if you screw THAT up!

Ken

 

Exactly!

 

Once you see a drop in pressure on the gauge, oil has dropped below the pickup and the pump sucked air. Air foams the oil and offers no lubrication at all. I would not be surprised if you suffered bearing damage. Just because its quiet and holds good pressure means almost nothing. The pump and relief valve are far oversized and can easily maintain pressure with major losses present in the system.