New 4.0 OHV heads - Now consumes tons of oil

[Jim Jermain]

I replaced the heads on my '00 4.0 OHV. I am now going through oil like crazy; about a quart every 180 miles. Before I replaced the heads it didn't use any oil. There are no visible leaks, no sign of oil in the coolant and I'm not getting any blue smoke or smell of burning oil.

I have three possible thoughts. I'm thinking oil is getting into a cylinder from the lifter valley through intake manifold gasket, possibly I have a stuck piston ring, or there is a problem with the new heads. The intake manifold gaskets seems most logical since if it were a stuck ring I don't think it would have just started burning oil with the head replacement and if it was a problem with the heads such as a bad valve guide seal I think I'd get smoke at start up.

I really appreciate any thoughts.

Thanks!!!

Jim

 

[Brandon96]

Can you verify your not leaking from the backside of the valve covers? Mine weren't on right when I finished my build and I leaked oil like a son-of-a-gun as well..

 

[Jim Jermain]

Brandon thanks for the response. Yep, it is not leaking a drop of oil. I painted the heads and valve covers before I reinstalled and they are completely clean. I'm just not sure if there is a way to diagnose without pulling apart.

I guess I'll start with the intake and see if there are any obvious signs of oil getting into the heads through the intake manifold gasket. If not I guess it's off with the heads and possibly pulling the pistons.

Jim

 

[jlsparky7]

What about the cam shaft seals?

 

[ragajungle]

I did the lower intake gasket on my B2 with a 2.9L (pretty close to the 4.0L) and I had a oil consumption problem from then on. It turned out to be leaking oil into the intake - the blue smoke was evident on start up especially , but not so much when running. also the idle was higher - because of the leak. How is the idle on the truck? Any CEL?

 

[Jim Jermain]

Thanks for the thoughts. The idle is great. I did have a rough idle at start up before I replaced the heads and it went through coolant. I'm pretty sure I had the typical crack heads on the 4.0 OHV. The new heads fixed the idle problem, but developed the oil consumption issue. The weird thing is I get no smoke at start up or when running. However with no oil in the coolant and no external leaks it's got to be burning I think.

The only thing I noticed before I pulled the heads was carbon / gunk on the threads of the cylinder 3 plug. This was the cylinder that had the crack. I'm wondering if the coolant leaking into the cylinder caused the rings to stick and it started consuming oil right before I replaced the heads.

Jim