92 CUTLASS 3.4L LOST 2 QUARTS OF OIL NEED HELP WITH FIX

[THETANK]

I have a 1992 cutlass 3.4 l with 56k. I just purchased the car about 2months ago. I changed the oil when i first got it and replaced it with 5.25 quarts of mobil 1 drive clean 7500 synthetic blend oil and a NAPA oil filter(I believe the previous owner used conventional oil ). I started to hear a knock the other day so i checked the oil it was about 2 quarts low after only 2000 miles of driving. I parked the car over a piece of cardboard for 16+ hours and not a drop of anything was on the cardboard. I then started the car and let it run for 10 minutes reving it several times and still nothing was on the cardboard. i then got under the car and it was dry as a bone as well. I have no blue smoke comming out of the tail pipes except for a very mnimal amount on startup. I had my brother follow me and I stomped on the gas a few times and he said no smoke came out at all. Where could all my oil be going?

 

Thanks in advance for your help.

[GutlessSupreme]

Check your coolant.

[94CutlassSLCoupe]

you may also have a bad intake gasket...it could be blown out so its sucking oil into one of the cylinders...and trust me, when that happens, you won't see blue smoke.

[THETANK]

I think the lower intake manifold gasket is the problem I checked the coolant and that was also a little low. I was looking at Fel -pro gasket set part number 95822 Here's the link does this look like the right part? Do I need uppper and lower gaskets?

 

 

http://www.partsamerica.com/ProductDetail.aspx?mfrcode=FEL&mfrpartnumber=MS95822&parttype=102&ptset=a

[GutlessSupreme]

You should always do uppers if you're gonna do lowers.

 

I was trying to make a point of your head gaskets though.

 

How does the coolant look?

[94CutlassSLCoupe]

I would think it would be impossible to do lowers without uppers on a DOHC

[THETANK]

My coolant looks clean no oil in it, that I can see. My service engine soon light did come on yesterday.

[Brian P]

my friend's old 3.4 DOHC used oil too, just as much.

[5speedz34]

Make sure if you replace the lower intake manifold gasket replace the upper too! and vice-versa.

 

FWIW: There is no oil running through the lower intake manifold on the 3.4's. And the only coolant is the t-stat housing and the tube that runs into the TB.

 

The only other idea is that maybe you leaked enough oil out that when you went to check it on the cardboard, the oil level was already down enough to not show up.

 

These motors are very tricky to get a good oil level in, they do retain alot of oil in the heads. I would fill it up and see if it leaks from there.

 

There is also a TSB from GM about oil consumption on the 3.4.

[94CutlassSLCoupe]

Make sure if you replace the lower intake manifold gasket replace the upper too! and vice-versa.

 

FWIW: There is no oil running through the lower intake manifold on the 3.4's. And the only coolant is the t-stat housing and the tube that runs into the TB.

 

I don't believe any oil runs through the manifold on the 3100 either...I know for a fact that my sister's had a bad lower intake gasket that was allowing the oil to be sucked in from the lifter valley...seems to me that the same problem could easily occur on a 3.4 DOHC

[5speedz34]

What I mean was if you take the 3.4's intake off everything is sealed there is no oil running in between the heads.