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Oil light? What oil light?

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Morris

Morris

Yoda
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My oil light has taken up the habit of showing its horrible horrible self while braking. And there is plenty of oil in the pan. Am I doomed?

I have also noticed a new oil leak, or at least my old oil leaks are now leaking with more vigor. Could the two be related? (it does not seem to be leaking from the oil pressure switch)

And the last mystery for today is that my oil is suddenly clean. I changed it about a month ago (haven't driven much over the month) and it was instantly black. Now it looks like brand new oil. What's up with that?

morris
 
Is your oil level low? If not are you running a mechanical pump? Are you getting poor fuel mileage? If you are leaking a lot of oil but the level is not dropping and the oil is clean, maybe you are leaking fuel into the crankcase. This would cause your oil level to stay up and get clean. It would also account for low oil pressure. Kinda a guess though.
 
And thinning the oil to the point that it leaks more.
 
/ubbthreads/images/graemlins/iagree.gif Both are classic symptoms of a ruptured diaphragm in a mechanical fuel pump. Check it out soonest, Morris. Oil pan explosions can be spectacular. And, can ruin your whole day.
Jeff
 
My car is fuel injected, so it no longer has a mechanical fuel pump. I did however have a recent near melt-down due to a bad fuel pump causing very lean running conditions. Perhaps I did melt down something that would cause these symptoms. Any ideas?
 
Oh, and how much damage am I doing to my engine every time the light comes on? Bear in mind, it only happens during heavy braking.
 
Has it been running rich so extended periods of time?
 
Morris, I wasn't sure if the problem was on the FI car.
I would check the oil carefully for fuel contamination, because if it is thinned out due to gasoline, potentially you are doing damage to the bearings and components by merely running it.
Gas is a lousy lubricant.
Do a leakdown test and see if you've got a problem there. It certainly sounds like gas in the oil.
Jeff
 
Morris:

You have a 1500 car, right?
If a 1500 Midget is fitted with a Spitfire 1500 engine, one must swap the oil pickup or the light will go on in braking. This happened to me years ago. I swapped the pan (the Spit pan wouldn't fit) but forgot to swap the pickup)
So does your car have a Spit engine or Spit oil pickup? They look quite different from the proper one (but you'll need to drop the pan to verify).
 
Morris - if you ran that lean for a while, I'd check compression. You might have cracked a piston - that would allow fuel to wash down into the sump and explain why the oil looks reconditioned. I'd expect power to be down though, so perhaps it isn't that.

I'd also suggest trying a knock sensor while you are tuning - check out j&s safeguard for example. Expensive, but less than a new engine.
 
Ooooh! Maybe this is it! The DPO had fitted the car with a thermostat that only allowed it to get up to 120F. I changed this out with a stat that allows it run between 175 and 185. Could these higher temps be causing my symptoms? I don't think (denial) I have a cracked piston. The vaccum signal is too strong. Also, I think that a cracked piston would result in burnt oil.

An engine rebuild is inevitable--it's really just a question of when. Much, much later I hope.
 
Hi Morris, my 1500 does exactly the same thing except I still have the pressure gauge. If I make a hard stop and the oil level isn't right at the top mark on the dipstick the oil pressure drops. I had inquired about this a while back and apparently my car was built with a Spitfire engine. It's the same engine it had when it was built, but when I replaced my dented oil pan I found it had the Spitfire-style pickup. I don't think the thermostat has much to do with it; mine will do this when it's hot or cold. Mostly I just make sure my oil stays at the top mark and I try to avoid making hard stops.
 
Make sure the injection system isn't dumping fuel in the intake after the engine is turned off. Leaking injectors can do this if the system holds pressure after the engine is turned off.
 
I topped the oil off and saw only one oil light after a particularly hard stop. So I am going to go with the Spitfire pick-up explanation. Ahhhh, BL. Your legacy of quality control lives on.

As for fuel in the oil... the oil definitely passes the nose test, so I really don't think that is a problem. But I will continue to explore this possibility just in case.

On the mystery of the clean oil... I have learned that it only appears clean when the car is hot. If I let things cool down and check the oil, it goes back to its ugly self.

Thanks for all the advice guys!
 
So, the new found vigor of my oil leaks had increased to such an intensity that I was leaving an environmental crisis zone every where I went.

I pulled the oil pan this weekend to silicon the oil pan gasket and see what I could see. I definitely have the long pick-up on my oil pump. But the hideous oil light has all but disappeared so I am not too worried about this problem right now.

What's bothering me is that I am blowing oil out my dipstick hole. For the short term, I will run a hose from my dipstick hole to my newly manufactured catch can, but I am wondering if there is anything I can do fix this problem short of an overhaul. I know conventional wisdom would imply that my rings are shot, but I do not have any of the other symptoms of blown rings. No burning oil. No "floating" vaccum signal. No loss of power.

Is there something else that could be causing this problem?

I am going to overhaul the engine eventually, but I just don't want to do it this year.

morris
 
If you have good compression on all 4 cylinders, you could perform a leakdown test to know the exact condition of your rings. I have a pretty good procedure that I got from Dave Russell a while back that I can forward to you. If the cylinders are tight then things might be as good as they are going to get. I know that I have a fair amount of blowby on my 1500 based on the leakdown test I performed last fall. I have to have the vent tube at the top of the valve cover ported to the ZS carb (seems like a manifold vacuum port and not a throttled port) or I blow oil out the dipstick tube as well. Nial, threaded his dipstick tube and plugged it but if there is a crankcase pressure problem, doing that will only force the oil out other places. He also built an adaptor between the carb and the air filter and that is where he vents his valve cover. How much vacuum can you make at idle? I'm not able to achieve more than about 16" without having the timing too advanced. I would do a leakdown test to see what is exactly going on in the engine.
JC
 
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