Dissappearing engine oil

GRWeldon

4th Gear Poster
Joined
Oct 5, 2023
Messages
294
Location
Alabama
Country flag
My engine oil is disappearing. It's not leaking, it's not burning it and the oil in the pan doesn't look like chocolate milkshake.

There doesn't appear to be any oil in the coolant tank. It's going somewhere and I can't figure it out.
 
Which car? My '98 Saturn wagon had the same oil disappearing problem and I finally fixed it last summer when it burned an exhaust valve and I just decided to refresh the engine. The waffle rings were completely stuck in their grooves. At the end it was burning about a quart every 300 miles, but it did not smoke going down the road (sometimes under heavy load). I would be willing to bet you might have a similar issue.
 
I recommend you specify at which rate it disappears.

My Continental used to burn one quart every 1,000-1,500 miles or so. There was blue smoke at the first start up of the day for a few seconds; otherwise there was no smoke at all.
 
It most likely is burning it, big puffs of blue smoke indicate excessive consumption but you don’t necessarily see gradual consumption. 94-95s are pretty bad between the valve seals/guides wearing and oil control rings gumming up
 
It most likely is burning it, big puffs of blue smoke indicate excessive consumption but you don’t necessarily see gradual consumption. 94-95s are pretty bad between the valve seals/guides wearing and oil control rings gumming up
Yup. Before I replaced my engine it was burning a quart a week. I’d fill the tank with gas and add a quart to the engine like clockwork.
 
Oil rings, valve stem seals, and what drips out of the leaky oil filter adapter gasket, Oil pan gasket, front main, and rear main seals, and pcv valve can be substantial on a 30 year old car. I'm using as much as TM, a quart every 1000-1500 mi.
 
I just made a round trip to Michigan, probably around 1800 miles. I had to add 3 1/2 quarts and I'm sure it's over 1/2 quart low now as I didn't check it when I got home.

It isn't making any puffs when I start it and I have been parking it on clean pavement. No drips. No oil in coolant. I would think that a burning rate of 2 quarts per 1000 miles would show as a smoky exhaust and the exhaust is clean.

It's going up on the rack today for inspection but I don't expect to find anything related to loss of oil. I'll keep y'all posted.
 
You have several cars in your signature. Which car, which engine?
 
It isn't making any puffs when I start it and I have been parking it on clean pavement. No drips. No oil in coolant. I would think that a burning rate of 2 quarts per 1000 miles would show as a smoky exhaust and the exhaust is clean.
You would have never guessed that my Saturn was burning a quart every 300 miles while driving it either. It did not smoke going down the road. Only the occasional puff under hard acceleration.
 
I just made a round trip to Michigan, probably around 1800 miles. I had to add 3 1/2 quarts and I'm sure it's over 1/2 quart low now as I didn't check it when I got home.

It isn't making any puffs when I start it and I have been parking it on clean pavement. No drips. No oil in coolant. I would think that a burning rate of 2 quarts per 1000 miles would show as a smoky exhaust and the exhaust is clean.

It's going up on the rack today for inspection but I don't expect to find anything related to loss of oil. I'll keep y'all posted.

Mine almost never did it on startup, after I changed to PI heads (startup is indicative of valve seals) But mine still consumed about that much, most likely from rings, some from PCV. I'd never see it in the rear view mirror
 
You have several cars in your signature. Which car, which engine?
#3. 4.6L. I topped off the oil in Auburn, Indiana...700 miles from my home. I stopped somewhere on the way and checked, down a half quart and topped it off. I didn't check it again until this morning after I got home last night. Barely shows on just the rounded end of the dipstick. I mean you wouldn't see it unless you were really paying attention. This isn't a normal amount of oil. I use synthetic oil, but if it burning at this rate there is no reason to use it...$40 a gallon, $11.50/qt. when buying individually. This engine now only has 96K miles on it. Should not be burning this much oil with nary any indication. If it were smoking like a powerplant I could see it (bah-da-boomph).
 
#3. 4.6L. I topped off the oil in Auburn, Indiana...700 miles from my home. I stopped somewhere on the way and checked, down a half quart and topped it off. I didn't check it again until this morning after I got home last night. Barely shows on just the rounded end of the dipstick. I mean you wouldn't see it unless you were really paying attention. This isn't a normal amount of oil. I use synthetic oil, but if it burning at this rate there is no reason to use it...$40 a gallon, $11.50/qt. when buying individually. This engine now only has 96K miles on it. Should not be burning this much oil with nary any indication. If it were smoking like a powerplant I could see it (bah-da-boomph).
I'd replace the PCV valve. Check for leaks at the oil filter adapter gasket. Maybe give the engine a Seafoam treatment. Possibly even pull the plugs and you could pour some seafoam in the cylinders overnight or ATF. Maybe the oil control rings are gummed up.
 
I'd replace the PCV valve. Check for leaks at the oil filter adapter gasket. Maybe give the engine a Seafoam treatment. Possibly even pull the plugs and you could pour some seafoam in the cylinders overnight or ATF. Maybe the oil control rings are gummed up.
Thanks for your recommendations. Maybe things are different today but when I took auto shop in high school (1978) I was taught if the PCV valve rattles when you shake it, it's good. Even so, they are cheap enough an I will replace it. With that being said, with oil usage at 2 quarts in a thousand miles, the oil has to go somewhere. I've owned some oil burners in my time but nothing this bad. All of those cars would produce blue smoke in the exhaust. None on this car.

I put it on the rack yesterday, no leakage whatsoever except a few drops from the transmission front seal. Not too worried about that because I'll be replacing that tranny in the next month or two.

I'm really at a loss for where this oil is going.
 
Well I've experienced some PCVs that still rattle but have crap built up inside so they don't open or close all the way. Like you said, they're cheap. Yeah 2 quarts in 100 miles is too much.
 
Well I've experienced some PCVs that still rattle but have crap built up inside so they don't open or close all the way. Like you said, they're cheap. Yeah 2 quarts in 100 miles is too much.
That was 2 quarts in a thousand miles.... Actually, I think it's more like a quart in 700 miles. It was only down 1 quart after driving 700 miles when topped off...
 
Keep in mind the cats are burning off excess hydrocarbons and that includes oil vapor.
 
I guarantee you are burning it. That is way too much to leak without it being blatantly obvious. That is probably too much to just be bad valve seals. My Saturn had good compression (180-190) across the board (well except the one with a burnt valve - 0), but consumed oil like it was going out of style. The waffle rings were stuck in their grooves and not doing their job. IT DID NOT SMOKE GOING DOWN THE ROAD.

You can try doing a piston soak and I have heard good things about Auto RX (although I still don't see how any of that stuff can free stuck oil control rings), but I would do a compression check first to make sure the top two rings are in good shape.
 
I thought the early modulars were known for using oil? My 93 would use a quart pretty quickly.
 
I mean it's not like there were so many options. Either it's leaking or it's being consumed.

If there is no oil pooling up under the car or anywhere else, then consumption (=burning) seems the only plausible explanation.

Unless...imagine there was a leak which only occurs while the vehicle is in motion?

:unsure: nah...
 

Similar threads

Back
Top