1984 Cadillac DeVille - Oil consumption

I have an 84 cadillac sedan deville roadster and the problem is its going through oil like its water it started off low I topped it off the next day I checked it to be sure it was good so drove after about 30 mins it started ticking like it was out of oil and shaking really bad so I took it slow back home to be safe let it sit for couple hours to settle the oil check it later in the day and the dipstick had no oil on it. I dont see any oil leaks or drips on the outter, just some wetness around the valve covers. I think it might something internally. any ideas?

If you are not seeing smoke, it must be leaking. Is the whole underside of the car coated. Park it over a newspaper and let it idle for 30 minutes.

if your going through a quart or 2 in 30 minutes of driving. its either leaking out somewhere, or you have a blown head gasket in which you would see smoke pouring out the exhaust or oil in your radiator.

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It has little smoke on start up for couple mins of warm up then goes away but didnt notice any oil in coolant when I checked it.

you need to take a good look under the car for wetness. i have seen oil leaks coat under the car all the way back to the rear of the car.

Ok will double check that and get back to you

another place to check is where the tranny attaches to the engine. you could have a rear main seal leaking really bad

I just checked undercarriage and theres wetness from the back of the oil pan all the way back to the crossmember in the center of the car and a constant drip every 2 mins off the bottom of the trans bell housing but the car haven’t ran in a week and half.

i would get a can of brake clean at the autoparts. spray down the area, let car idle and pin point the exact area where it is leaking. from what you are saying its either the oil pan gasket or the rear main seal.

Ok will try that.

Cleaned it had it idle for 15 mins and started running down the side of the bell housing and dripping through an opening on the bottom of the bell housing included pic.

I would say its the rear main seal is leaking. transmission would need to be dropped to replace it.

So I take it the amount of work needed to be done for that with transmission removal alone is a costly job?

i would call a good mechanic if you know one or a few tranny places and get some prices. it might not cost as much as you think. the seal is only about $10. it all the labor costs to remove tranny. good luck

Ok will do thank you very much.

Can you please post a picture of your car. I can’t locate a Sedan DeVille Roadster on Google.

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That is a Sedan, where did “Roadster” come from?
Did some more searching, for some unknown reason I see other sedans with Roadster tacked on.
The only post war Cadillac that could be considered a Roadster would be the XLR.

Yes I thought that was weird to never heard of a sedan roadster