I have a smooth running 51 Plymouth flathead 6. I had some strange sounds from my engine today. It was coming from the rear near the exhaust hole in the block. So I turned around and headed home and on my way the sound got louder. My wife said white smoke was coming from the tailpipe. It ended up sounding like a cracked exhaust manifold so since I am replacing my intake and exhaust manifold anyway I yanked it apart today. As I was removing everything and a few things were discovered; 1.) the rear-most bolt on the exaust manifold was broken off and was found up the street 20 yards or so (possible cause for the sound) 2.) when I removed the exhaust manifold bolts anti-freeze poured out of the holes, is this normal? 3.) I also had oil in the anti-freeze, what possibly caused this? (possible head gasket?) 4.) should I remove the side engine plates for inspection or adjustment? What should I check for and does any of this sound right? Any info would be greatly appreciated! Thanks, ******Knuckles
My first guess is head gasket, it's an easy fix on a flat 6. Yes, the manifold bolts screw directly into waterjackets, so they leak when they are removed. remember to put sealer on them when you put them back in. Removing the sidecovers probably won't tell you much, but it wouldn't hurt to have a look around. Was the sound you heard kinda a ticking like when a hydraulic lifter sticks? More than once, I have seen flat 6's break the top compression rings, then break a chunk out of the top of the piston and bounce around the cylinder. eventually, it works its way out the exhaust port and the sound goes away.
Bugman, Thanks for the response. This helps out alot! As for the sound, it was like a bad exhaust leak. I better get to work on it. Thanks again, ******Knuckles
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