I just rebuilt the 460 in my 83 F350. Runs great but the sucker is burning oil. I went to the dump (a 75 mile round trip) and burned 2 quarts. I noticed when I let off the throttle (coming down a hill) it would smoke like crazy. There were definitely no mosquito's followin' me. It only seems to do it when it is warm and also if I drive it for a while then start it up (after it sits for a while) it smokes like worn out valve guides. The heads were rebuilt and new guides installed so I don't think that is the problem.

Here's what I have done so far.

1) replaced the PCV valve and checked to make sure the oil was draining back to the oil pan and not pooling up in the valve cover.

2) unhooked the PCV valve and ran it like that and it didn't help.

3) pulled the plugs and the ones on the right bank were wet and had oily deposits. #1 and #7 were the worst. The ones on the left looked a little rich but other than that OK.

4) pulled the valve cover and looked things over, made sure the valve seals were there (umbrella type unfortunately, I asked the machine shop to install seals in the guides and they spaced)

5) oh yah, I checked the compression for the heck of it and all were good, all right around 150-160 Yes I did install the rings correctly.

It almost seems like it is pulling oil through the intake gasket. The thing runs good and idles good, I would think it would act like it had a vacuum leak if they were all leaking (on the right side)

Any ideas and suggestions would be greatly appreciated. I don't know how many of you caught the Thread about the Napa Rebuilt Engines I posted but this is the third time I have had an engine out and back in and I'm getting kinda tired of working on it. I was hoping to avoid problems by doing it myself this time and see what I what I got for talking bad about NAPA!

Sorry for the long post and thanks for any advice,
Bruce

 

I have had the intake gasket suck oil like that. And it is suspicious that it's only on one side. You could pull it off to check it. A sure sign I have found is the gasket seperates easily, and the surface of the gasket is wet. If you find it looks bad, then get a good quality gasket and try again. Don't try to use any sealer except around the water inlets. You may also want to toss the end seals on the manifold, and use a bead of silicon only. This works good for stopping oil leaks, and may let the manifold set down lower on the engine, making a better seal on the middle ports.

 

Franklin,

When you had the problem before did it run ok or did it act like it had a vacuum leak? It is suspicious that it is all on the left bank. The only thing that I see that is common is the intake manifold. I do have quality Felpro gaskets but I did use the rubber end gaskets. Also I did use sealer only around the water ports. I retorqued the manifold yesterday and put my new door panels and pockets on and am in the process of installing the new insulation and vinyl floor covering and will then take it for a test drive. I'll post the results.

Thanks,

Bruce

 

ya id chuck them rubber gaskets and use some black rtv on the ends to seal the intake.........just a thought here but was it decked

 

The machine shop checked the decks and they were good. I am just headed out to test drive it and see if retorquing the intake helped matters. One thing I forgot to mention.

I had a breather on my oil filler cap and when the engine is running it is pulling a pretty good vacuum through the breather. I took the cap off and put my hand over the filler hole in the valve cover and there is a pretty strong vacuum there. Seems more than normal, any ideas what is normal? I think I'll try and hook up a vacuum gauge and see how much it is pulling. The more I think about it and the more people I talk to makes me think it's time to pull the intake and check it over good and reseal it.

Thanks,

Bruce

 

Thanks for the suggestions. The intake gasket on the right bank was leaking on all four ports. I am putting a new one in tomorrow. I looked it over and cleaned it up good, still don't see anything that tells me why it was leaking. I got a tube of "The Right Stuff" and will use it for the end gaskets.

Bruce