I have a 1997 corolla 1.6 with 215k miles on it. and put a new head gasket in about 500 miles ago. Along with the head gasket I replaced a cracked exhaust manifold, water pump, the (yes) original timing belt (what’s the record?) and put in new fuel injectors as well as replaced the valve seals. I also replaced the crank seal, water pump, and put in a new pcv valve, wilres and rotor.
The old head gasket was leaking oil, not coolant, and there were signs of heavy oil burn in two of the 4 cyls (1 and 3) with a lot of white deposits on the plugs and exhaust vales. I used a brass brush to clean off the valves, but did not lap them when I put them back in. The new valve seals seemed to go on fine and I applied a light coat of grease to make sure they were lubed at startup. I didn’t want to have the head shaved, and didn’t want to lap the valves because I didn’t want to change the compression so much that it would cause the rings to suffer when I got it back on the road.
I put the valves back together and coated everything with assembly oil before putting the valve cover on. Startup went fine and no C.E.L., no smoke.
400 miles later I checked the oil…1 quart low. I thought, ok…galleries in the engine are now full, and added a quart.
Next morning I notice a blue puff from the tailpipe on startup. Hmm…valve seals not worn in yet?
A hundred miles later, and a blue puff each am., I’m on my way to work and the oil light comes on. I stop. No oil. Put in two quarts and drive to a gas station, put in 1 more. It’s full. Drive to work ten miles, still full. Drive home from work, 15 miles, half-quart low and lots of blue smoke when accellerating post-decel, especially at the bottom of a hill when starting up. But no blue smoke at idle, even hot (when I got home). Idle two minutes and give it gas…blue smoke. Give it more gas…no smoke. No water in the oil, and no oil in the radiator…clear green fluid. No copious leaks on the ground, even after a few minutes of idling.
I have two, maybe three thoughts and I’m open to ideas.
Valve now not sealing because I brushed away carbon deposit allowed compression to blow past the valve seat and pop off the seal, so now I have a valve with no seal? Possible. Could even happen to more than 1 valve.
Oil return gallery plugging and oil is building up under the valve cover, causing it to drain down the valve guide. Could happen, I suppose.
Crankcase vent system plugging? A quick check of the pcv hose showed it to be reasonably dry, but I could check the intake chamber (which did have a lot of carbon in it before the head gasket change.
I’ll pull the plugs and see if one or two cyls show oil combustion deposits, or if all do. Also considering a compression check, though I think the rings are ok based on the way the blue smoke is showing itself on cold start and when accelerating uphill.
And finally, still no C.E.L. The car starts and idles fine, though on the highway it does “surge” a bit (presumably this is when oil is hitting a cylinder?)
Thanks for your thoughts.