I ran into an interesting problem today. I was driving my Midget toward
Knoxville on the interstate, when I noticed the heat guage was pushing
upward. Watching it closely, I decided to get off at the next exit to check
the water, when a loud clattering noise started from under the bonnet. I
pulled immediately over to the shoulder and under an overpass.
As soon as I stopped, steam began rising from under the bonnet, and the
clattering was still loud. I shut her down and raised the bonnet. First,
the heater hose had burst and was spraying out hot water. No-brainer! I
loosened the radiator cap to relieve pressure, then pulled the hose off, cut
it off behind the burst, and reinstalled it. Easy enough. Started it back
up and the clattering was continuing--got out to see where it was coming
from--unmistakeably from under the valve cover. I pulled the valve cover,
and found that one of the pushrods had jumped from under the rocker arm and
was playing titter-tatter on the underneath of the valve cover. Eyeballed
it and determined it was straight, and reinstalled it, setting it by feel, as
I didn't have a guage with me. No water--I found about 2 cups of rainwater
in a flat container that had been discarded alongside the interstate, which I
strained out and put in the radiator.
Started back up and back on the interstate--engine running fine, but
starts to overheat again. Drove to the next exit, probably 2 miles, and
added cool water at a service station. Back on the interstate, it seemed to
run a lot cooler to my destination. After that stop, back in the car and on
the interstate again, and we are overheating again--badly, but not in the red
zone yet. Pulled over and added a little water (she boiled prolifically when
I opened the radiator cap. Ran about 3 more miles--still overheating, so I
pulled into another service station where I removed the thermostat and filled
the engine with cool water again. The 'stat is a 180 degree stat that was
hot and wide open when I removed it and closed when I ran cold water over it,
so it was working. But without the thermostat, the engine rans cool and got
me home just fine.
I am wondering what the hell is going on? This is an engine that normally
runs cool--in fact, last year I had to install a 190 degree 'stat to get
engine temp up to optimal temp. True, I did change blocks, and used the
water pump that was on the new used block, but it has been running just fine
until now. And the thermostat was OPEN when I removed it, indicating that it
was letting water go through. But when it was removed, the engine stopped
running hot.
AND, what made the pushrod jump from under the rocker arm? The rocker arm
was adjusted to spec and when I found it loose I checked the locknut and
adjuster and both were tight. The pushrod seems straight, although I will
recheck it by rolling on a flat surface.
Any ideas? Thanks!
--David C.
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