Hi Guys: My 63 LeSabre (401 engine, 93k miles, never rebuilt), developed a sudden and big coolant leak. Have had the car for 1,600 miles and it never smoked and never showed signs of coolant level dropping. The other day she started smoking like crazy out the tailpipe (white smoke), and by the time I noticed the smoking I had lost a gallon of antifreeze in probably just a 30-minute drive. No sign of water in the oil. I spoke to Russ @ Centerville Auto Repair who said "nailheads never blow a head gasket," but that they can rust out. Hoping it is "just" a head gasket. Grateful if anyone has any additional wisdom to share or similar experience of this sudden coolant loss before I get someone to go fishin' and take off the heads. Thanks! Vig
Russ is pretty well right on.... nailheads dont pop headgaskets much because they have a center bolt.... but composition gaskets rot out... the real test is to do a good compression test and that will pin it down... if one gasket is rotted to that point , the other one probably is nearly there also.... I would replace both of them....
Once you pull the head on the bank that is smoking and before ordering any parts get that head to a shop that can pressure test it and check if it's out of flat by more then .002". If it checks good and it turned out to be a failed head gasket then pull both heads, get new head bolts and confirm that all the head bolt holes are clean and allow a bolt to thread in easy. Then your ok to oil the bolt threads with 30w oil, slap in the new head Gaskets and Torque them up in 3 to 4 steps, the more the better!
You dont have to buy new head bolts... nailheads do not use tork to yield bolts... they are the good old reuse a million times bolts... just be carefull that you clean both surfaces really good before putting the heads back on and clean the bolts with a wire brush.... you can also run a bottoming tap into the bolt holes and clean them out with compressed air... I also coat the bolt threads with anti seize compound... instead of motor oil...
Failed intake manifold gasket is a possibility, you can inspect them first when you pull the manifold.
Oh yeah! And I just had mine off.! I was in "intake leak" mode. I have done 3 for same symptoms lately, 2 of my 3800 V6's and brothers 4.3 Chevy.
