first74

Hi all. We'll I'm definitely no auto mechanic but learning things as I go. So I've had this 74 since April. Changed the oil about a month after I got it maybe a couple hundred miles or so. Level was good before the change and ever since then every 200 miles or so I'm a quart low. That's probably even being conservative. Changed the plugs a little while later and they were pretty black. Definitely not leaking oil but good amount of white smoke at startup. So I read could be valve seals. I'm changing them now. It's been I'd say about 500 miles since plugs were changed. Start with the odd side heads 1,3,5,7 and the plugs didn't look that bad. A couple of the umbrella seals were like real hard brittle plastic. Started the right side tonight and all but the #2 plugs were extremely black and crusted. The o ring seals were pretty thin and so far one real hard and deformed umbrella out of 4 valves. Could bad seals do this to the plugs and cause that much oil to be burned. Also how much clearance is normal between valve guides and valve stem? They seem a little sloppy.
Thanks for your help . Brent

MelWff

everything I've read says .003 or more is excessive wear. Did you get lots of blue smoke when backing off the gas?

Jud Chapin

If the white smoke is just at start up, it's generally due to condensation and is considered normal. If the white is present after warm up, that's a sign of a possible internal water leak. Valve seal problems generally create blue smoke at start up. Burning a quart of oil in two hundred miles is a lot and could be worn rings. I would do a compression test.

zwede

Many possibilities for burning oil. Some of the more common ones:

• Aftermarket valve covers with crap (or no) baffling for the PCV valve
• Failed intake gasket
• Valve seals
• Worn valve guides/stems
• (Automatic only) Bad vacuum modulator, sucking transmission fluid into intake
• Worn piston rings
• (Aftermarket heads only) Rocker studs that enter the intake ports and no sealer used on threads.

Tin_Can_Terminator

Also, a loose intake to add to the list.

TCT

first74

Thanks all for the replies. I changed the valve seals, I'll see what that does
Have a feeling the worn guides are my problem.