I had some really bad news this weekend. My 3 year restoration was completed last Friday with competion of my interior. I took it Saturday for it's first car show. I took best GM and best in my class. I was however was driving home and noticed blue smoke!! Not good. The smoke was coming out of the rt tailpipe. I'm thinking ring on the #6 cylinder?
My questions is, The car is a 68 Convert w/air. I wanted to pull the head off and pull the piston out though the bottom. The only issue is the lower rear valve cover bolt won't come out? Has anyone had a good way to take the out that bolt? I tried with extension and swival but could not get @ it.
My other question is should I just pull the engine? I'm thinking it might be tough getting the rear head bolts out on the rt side?
Before pulling everything apart, Id check plugs, then do compression tests, basically test everything and anything you suspect before pulling the engine. Maybe you'll get lucky and it will be something else...something simple that was overlooked...
I agree with Wisc. Comp check, and a leakdown will help diagnose the prob. Than if it means dropping a piston out definately pull it out of the car. It's not so bad. Just takes time and some patience.
The motor sat for a little over a year w/o being run and I probably put 100 miles on it before the problem? I checked the plugs last night and #6 was fouled and black! It looks like that cylinder is my problem.
Hard to say without seeing it. But if you check compression and it's good, I'd have to point the finger at a bad valve guide seal before the rings especially if it ran good while burning the oil.
Generally blue smoke is gas and black smoke is oil but sometimes it's not that easy to differentiate. You've got to get that valve cover off to make sure the valves are opening and closing like they're supposed to. I hate to say it but start up after a year is real hard on parts like a cam because all the lube has long since drained of the lobes.
Other way around on oil smoke (blue) and excess fuel smoke (black) and add coolant "smoke" (white) or trans fluid smoke (white).
Check all fluid levels and conditions. Listen to try to narrow down noise source. Determine if smoke appears on acceleration, deceleration, cruise or startup. Have a friend watch your tailpipe while you drive. Check the spark plugs and tailpipe for residue after 5 minutes or more of operation.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
No suggestions on the bolt but pull that valve cover and check to see if it has sure seals installed on the guides. Also check to see if oil is puddling in the valve cover. (not draining back) If you put that much in and only about half came out it might just be loading up in the Valve cover and getting by the guides.
Big iffy but it never hurts to hope for a simple solution.
Last edited by ho428; 05/21/0911:21 AM.
Wanting a Custom fit in an off the rack world.
I don't have time for a job, I just need the money.
Also check to see if oil is puddling in the valve cover. (not draining back)
Excellent one. I bought a nearly-junk '89 Acclaim a few years ago that generated heavy smoke screens. I had to change the cam plugs and rocker cover gaskets since oil just ran right out of them, and found that the webs that usually drain the oil back down were covered with a varnish-like layer.
Cleaning and sealing it didn't stop all the consumption, but it definitely helped.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
I wish it was a simple solution. We pulled the motor last night and found unk issues. The #6 cylinder has a loose piston? I'm confused. I grabbed the top of piston and there is slight play in it. More than the other cylinders? I'm planning on pull the piston out tomorrow to see what the issue is?
Ugh. I hate hearing that. I just went through that with mine. Only my piston wasn't loose. I had two of them with the sides blown out. Don't think I'll ever use cast pistons in another motor. On the upside it was under $600 to fix. I think I got off cheap. If you need a new set of forged pistons let me know. I may have something you can use.
Update on the motor. I had a local engine builder look @ my motor on Friday. When I bought the car three years ago, the guy I bought it from in Dallas told me his brother (the GM mechanic) had rebuilt the motor. Well, I turns out he was has part right. He had the block bored, stuck in used pistons and did nothing w/the heads? It doesn't sound like a overhaul to me?? I was so pi$$ed to hear this! I'm not sure what I'm going to do w/him yet?? Any thoughts?
On the other hand I was lucky to find a 400 out of a 68 GTO for $800 which I bought over the weekend and actually got put in over the weekend. I needed to have the car on the road by Hot Rod Power tour in 2 weeks!
