1 quart + over, is it ok to run?

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So I go over to my friend's house the other day and he had just done an oil change himself. He has a 4.5 quart sump, and what he usually does is he buys a gallon jug (4 quarts) and then a single quart bottle and dumps it all in.

This time I asked him how much he paid for the gallon jug, and his price was a little higher given the plain dino he got. I look at the jug to see what kind he got and I see that it was a 5 quart jug instead of the gallon. So he ended up putting 6 quarts in his engine not knowing he got the bigger jug.

We jacked up the car and drained out 1 quart of it, but he had been running that amount for at least a week or so.

So is there any concern about running this much over the correct amount or do most engines have a wide allowance for overfilling?
 
Depends on the car. Personally, I never go over .5 extra quarts. Never had a problem. 1.5 extra quarts would make me rather nervous.
 
Yeah I thought so too.

What kind of problems exactly would be caused by running 1.5 quarts over for an extended period of time?
 
1/2 quart over isn't bad.

sometimes if there is too much oil, the crank windage can pick it up and through it against the cylinder walls. If there is too much oil on the cylinder walls, the oil control rings wont be able to remove it all and the engine will start to burn oil and cause carbon buildup in the combustion chamber. Thats why high perfomance engines use dry sumps.
 
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Suck some out.




I did just like I said in the first post.

But the kid did run it for over a week with 1.5 quarts over, which is what I'm inquiring about. Right now it's running the correct amount.
 
I'm suprised he didn't notice it high on his dipstick when he got done changing the oil.
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He more than likely did no permanent damage and is now fine.

Running too high of a level can cause frothing of the oil, oil burning, higher crankcase pressure, and other problems. Exactly how much is "too much" depends on the specific engine in question.
 
It depends on the car. I routinely run 6 quarts in both my Buick and my Chevy truck. The Buick specs 4.5 and the Chevy 5.1 quarts. I run an oversize filter in them, but that only holds an extra 4 ounces.

I'd tell your friend to pull the dipstick right after running the engine some; if he finds no bubbles on the dip stick (which would indicate foaming) then everything is probably alright.
 
since you got the extra oil out, everything should be fine if he hasn't had any problems. but I wouldn't run that much. oil foaming and possible seal leaks from too much oil
 
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and possible seal leaks from too much oil




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Description: The crankcase ventilation system, often called positive crankcase ventilation (PCV), consists of a PCV valve or metered orifice (calibrated opening), its vacuum hose or line, a supply hose providing air into the crankcase, and on some applications, a breather filter to clean the air provided to the supply hose.

Purpose: The purpose of the PCV valve is to regulate the flow of crankcase fumes into the intake manifold where they can be burned. Prior to 1963, cars had no PCV and used road draft tubes that just left the hydrocarbon emissions from the crankcase out into the open air. The PCV valve also has a secondary role as a check valve, to prevent flow back into the crankcase. This prevents potential ignition of the crankcase fumes, should the engine backfire. The PCV system is also crucial for to proper engine sealing. The system alleviates crankcase pressure, which can push out on seals and gaskets, contributing to oil leaks.



http://www.carcare.org/Engine/crankcase_vent.shtml

I'm thinking if the engine is properly vented to the outside atmosphere, there shouldn't be any chance extra oil blowing the seals out. Your thoughts?
 
Oil pressure shouldn't be confused with pressure confined to the interior of the engine. Seals aren't 'blown out' due to an overfill situation. Foaming may occur due to crankshaft contact with the oil, and in some engines with worn oil rings, some oil may enter the compression chamber causing plug fouling, but it does not cause excessive interior pressure that would affect any seals. Oil pressure remains constant at operating temperature no matter how much oil you have in the sump, unless cavitation occurs due to foaming, but that's a pressure DECREASE. Excessive oil does not cause excessive pressure.
 
^ That's what I thought. So the only danger is the crankshaft striking the oil pool - causing the oil to foam up - causing oil pump cavitation; correct?

And if there's enough extra room for the extra quart under the crankshaft, then everything's fine; correct?
 
If there's adequate clearance, cavitation won't be an issue, but in the case of my friend's Cutlass, he rebuilt the engine by hand, adding some performance upgrades along the way. After the new oilpan was installed, the dipstick was no longer accurate....so, the dipstick read 'low' and he kept adding oil and the engine kept consuming it. The extra was finding its way into cylinders #4 and #8, fouling the plugs. He became convinced that he had a compression problem on until checking into it and finding that he had been grossly overfilling the engine for several weeks. Foaming wasn't a problem, but oil-into-cylinder intrusion was. If your oil rings are in good shape, it should take quite a hefty overfill to cause this scenario...but it can happen. I've overfilled nearly every engine I've ever owned, mainly because nearly all have taken some wierd amounts to refill, so I just round up to the nearest quart..usually netting about 1/2 quart overfull. I have to say if I'd ever discovered I'd overfilled by more than a quart, I'd have drained some out. Oil-into-cylinder intrusion can be very hard on emission equipment...cats don't like it.
 
Okay, I'm trying to figure out how oil into cylinder intrusion is going to occur with zero crankcase pressure from a well ventilated engine?
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I wondered that myself when his problem occurred. The problem with #4 and #8 stopped when he installed the correct dipstick and got his oil level where it was supposed to be. I even ventured to ask a couple of technicians at the GM shop I worked at about it, because it wasn't logical to me. They just said that the engine's internal design allows for only so much space to be occupied by oil before it's going to start looking for 'somewhere to go' during engine operation. They had no explantion as to why only #4 and #8 were affected, unless the engine was slightly tilted to the rear. Neither of the techs indicated that this was abnormal for an overfilled engine. I guess I'd have to talk to an engineer to get the specific details of why this happens.
 
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