Scott,
<< The overheating problem continues and I've been looking for an electric
fan. I did add an overflow bottle to turn it into a closed system. Problem
is, after driving the car for a few miles (long enough to get it hot) the
vital fluid spews out of the rad cap under enough pressure that it goes all
over the car or the pavement, rather than into the bottle. Any thoughts?
>From what you describe, I really wonder about the theromstat being stuck.
Does the temp just steadily climb? If the thermostat is working and
waterpump is pumping, you should get to drive awhile before things boil. It
is also quite possible to get new rad caps that are bad.
>>It has a 4lb. cap. Could it just be a baffed cap? Should I consider upping
the
rating? If so, how high should I go? 7lb?
I'm using a 7 lb cap on my +4. Before I added the electric fan and had a
modern core put in the rad, I could run at 60mph or so with no concerns. If
I started to hammer it in 90-100 degree weather or spent time in traffic
clogs it would do some serious gauge climbing. With the new rad core, and
electric fan and a shroud to duct air to the rad, the temps are fine all the
time and the electric fan rarely comes on.
>>The other problem that has been developing is a nasty vibration. It seems
to happen at between 2800 and 3000 rpm but not under load. In other words
it's at its worst when I'm travelling at a steady speed >>
Have you checked the driveshaft u-joints? Another possibility is the muff
coupling. If the muff is sloppy and gets loaded with the input shaft a bit
out of line that could cause a vibration. Try pushing the clutch pedal,
bring up the revs a bit and let the pedal out before you drop the revs. If
the vibs go away, you might want to check the coupling. I have a vibration
similar to what you described that comes & goes. Using a frequency analyzer,
I've found its signal to match the transmission input shaft speed. Now all I
need to do is get around to pulling the tranny..........
Happy Hunting,
Ken Payne, 63 +4 4 seat
|