Here is the story folks...
Drove the car early on a chilly Sunday morning, approximately 60 miles on the highway. No problems.
Car then sat for 1 hour, restarted fine, drove approximately 5 miles on the highway, then noticed a loss of power. No pop or boom or wierd engine noise was noticed. Felt like the same cylinder was missing over and over from the rythm of the engine lightly shaking the car.
Pulled off of highway and noticed blue smoke from exhaust on exit ramp.
Took a look and didn't see anything unusual in engine bay or beneath. Oil pressure normal, oil level normal, oil temp normal. Slowly got the car back up to speed, hit the cruise control, 5-10 miles later the problem went away.
Troubleshooting thus far:
-Found a slightly fouled spark plug on cylinder #5 (likely the cylinder that was misfiring)
-Checked all headstuds and rockers and valve clearances, all ok, clean and tight
-Drained and changed oil, smelled like gas, but no strange parts floating around
-Checked resistance on cap, rotor, plug wires, plugs, all ok
Went for a 1/2 our drive last night with new oil, no problems.
'85 Carrera, 34,000 miles (10,000 in the past year), oil consumption approximately 1 quart per 6000 miles, oil and filter and valve adjust 1000 miles ago. (Castrol GTX 10W-40, Mahle OC-54)
What are some ideas as to where the oil and gas are mixing? My first thoughts were a broken headstud, cylinder ring, or valve guide, but those aren't things that typically fix themselves. Next on my list is a compression test, what else can I do?
