dmwil

Mine makes oil disappear, too, since 40k. There have been times where it slowed down and times where it just makes me scratch my head. I've never seen any leaks, but only minor seepage at the upper sump gasket. I had that replaced under warranty and it stopped. I thought I'd found the culprit and that maybe it was just throwing it out while driving, because I've never had a drip in the garage or driveway. Well, that lasted a few months and then it got right back to drinking.

I think this engine is an oil burner, plain and simple. It drinks and drinks and then behaves itself for awhile, then it starts up again. Twice I've replaced the PCV valve. Once it cut the consumption way down. The other time it did nothing. I

Has anyone installed a catch-can? I'm wondering if that might tell the tale and capture the oil that is going missing?

I just keep driving it and it continues to run reliably as always. We'll see how far she goes. Some times I think I hear some noise deep in it, but I'm not really sure. If it ever goes south, I've got the warranty.

One moe question...Does anyone who had their 3.8 replaced under warranty know if the new (I'm guessing remanufactured) engine addresses the oil burning issue, or do they wind up doing it, too?

Mr.T

Thanks for starting this thread, very interesting.

Mr.T

The dealer should have changed the oil after all the other work -- Did they use a higher viscosity then what you've been using (for example 5w-30 instead of 5w-20)?

dmwil

I've used 5w30, 10w30, and 0w40, and in the end, there was no real difference. There was a period where the 0w40 seemed to be consumed a little less, but that didn't last. In fact, the last time I ran a couple thousand miles with only a little usage was with 5w20. Overall, I'd say the one variable that showed consistently less usage, but not by much, was with Mobil 1 high mileage oil, no matter the weight.

Rednroll

There are 3 items that I'm aware of on the 3.8L which have been attributed to loss of oil.
1. PCV valve needs to be replaced. $10 part, easy to replace just do it if you haven't.
2. intake manifold gasket as outlined from the OP.
3. I have not seen this one for certain, but it seems to be a popular internet rumor that the cylinder piston rings have been installed upside down from the factory. I have my doubts with this one, since it would seem to me that if oil is getting past the piston rings and burning, then you would be seeing black/blue smoke coming out from the exhaust pipe.