Originally Posted By: crw
Back to this never-ending saga...
I eventually got to doing a compression test. Big problem... the compression on all cylinders is dramatically low, around 40. Each should be around 90 for it to start.
But then I started struggling with the notion that it started and ran fine last fall, and now, ALL cylinders were so low...
I ran this past a lot of experts on a Ford N board. Nobody had an explanation for it. Then this past weekend I was talking to a friend who said, "Maybe you froze your block. Have you checked your anti-freeze?" Wow.......
You see, this is the first diagnosis that matches the data. It ran fine in the fall, then all of a sudden the compression is way down on all cylinders. Cracked block.
I checked the radiator and the level is about 6 inches from the top. My oil "looks fine", but the level is right on the full mark, and probably more full than I should have expected on this OCI.
So, I'm probably "sorry-out-of-luck" on this one. Is there any way to tell if there is a lot of coolant in the oil, short of paying for anything like a UOA? I'm not in the mood to spend anything more for this, but I suppose doing a UOA might be worth it just to be sure.
Seems to me compression was mentioned early in the thread.
Now, if I have your attention, it's perfectly normal for the radiator on an N to be "way down". Anything over the fins will burp out the overflow when you get the engine warmed up. The radiator on an N will never stay full.
Let me repeat-the radiator on an N will never stay full.
That doesn't mean there is a cracked block.
I'd expect to see low compression on one or two cylinders if the block were cracked, but not all four.
Pull the spark plugs, make note of the position of the plug wires. Drain the coolant (one of head bolts extends into the water jacket). Remove the head bolts with an 11/16 wrench. Note their locations because there are some size differences.
Note the condition of the gasket once you remove the head. Not bad? Ok, next turn the engine over. The valves aren't closing completely, correct? Those little round things next to the pistons (the big round things)?
Take off the manifold, take off the little valve covers, take some cleaner and a brush and clean up the gunk around the springs and valves. Get them freed up and working.
Put it back together and fire it up.
One more question-has the engine been rebuilt in the last 5 years? There was an issue for a while with after market camshaft gears made of fiber rather than metal. They tended to wear out very quickly throwing the entire valve train out of time.
If you haven't had a rebuild in the last 5 years or so then it's probably not an issue.