: '95 Northstar 4.6 oil leak

Lloyd DeYear
12-18-05, 05:50 PM
'95 Eldo bought new. Has 75,000 K. Seal between upper & Lower block section was replaced under warranty at about 20K. Now pouring out oil again. Has anyone gotten help from Cadillac on this problem? Very high cost to replace. Oil has been changed at about every 4000K and car never abused. HELP!!!!

12-19-05, 01:45 PM
I've got a 96 and te dealer just told me that mine is leaking a little. That's not a good thing.

12-19-05, 03:03 PM
If the oil is "pouring out", it's probably not the the seal between the case halves. Check the oil filter adapter, and oil cooler line o-rings, if equipped. A case half or oil pan leak is usually one or two drips overnight, at the most.

12-19-05, 08:27 PM
I am with Jadcock. Halfcase usually is nothing more than seepage as it is not under pressure. My '97 was replaced under warranty. I sold it in Oct. with 107K on it and it was as dry as death valley.

12-19-05, 08:38 PM
You're probably thinking about the oil manifold, not to be confused with the half case seal. The oil manifold is a 1/4" plate between the pan and lower block. It is under pressure, and I believe it distributes oil to bearings and such...

12-19-05, 10:22 PM
Hmm, are you sure you are not talking about the windage tray? Don't the bearings get their oil through the crankshaft?

12-19-05, 10:28 PM
windage tray is a thin steel stamped thing. I'm talking about the 1/4" plate. The plate forms the passageways (or at least seals the bottom half) for the oil to get from the pump in front to the bearings.

12-19-05, 10:47 PM
OK, I concede as I am not that familiar with it without looking at a service manual. I didn't think that would leak externally but, like I said I am not that familiar with it.

12-20-05, 07:18 AM
I don't believe the oil plate is external. The only external mating surfaces on the lower block are the seal between the upper and lower case half, and the oil pan.

12-20-05, 08:45 AM
Refer to this thread...
I posted pics of both sides of the manifold so you can visualize the seal. In the first photo, you can see the windage tray laying in the bottom of the oil pan. If you decide to replace the manifold be aware that the new design has changed from the original and with the new manifold you MUST replace the windage tray AND oil pick up tube. Lack of this information led me to have to timesert the main bearing bolts.