Sunbeamers:
Thanks to all the suggestions and help I've received from the list on
this subject, as usual.
I spent more time last night on my temp. gauge readings versus the
actual water temp. in the cooling system. I tested my brand new temp.
sender in a pan of hot water while it was hooked up to the gauge, and
compared this to what my multimeter temp. reading was. The new sender,
to start, did cause the gauge to read slightly lower than the old, but
still showed too high on the gauge. Numerous readings at different
temperatures (and running up and downstairs after boiling the water to
get it to the car before it cooled off too much) verified that my gauge
was reading close to 30 degrees hotter than actual temperature..i.e.
when the gauge read 220, actual water temp was around 190. At lower
actual water temperatures, the gauge wasn't quite as far ahead, but
still not accurate and showing 185 or so when the water was really at
170.
So rather than send the gauge off to someone like Margaret at Mo-Ma who
actually knows what they're doing to get it re-calibrated, I did
something that I do not recommend to anyone since you could ruin your
gauge in the process. I took the gauge out and apart and slightly bent
the needle to the left, just below the 1/2 cover that covers up the
needle. It's very tricky as the needle and assembly is very delicate and
it took considerable trial and error (and lots more running and
re-boiling the pan of water) to get it right and not break it, but that
gauge now reads as accurately as I think it's capable of doing. Between
170 and 195 or so, on the gauge, the readings are exactly dead on. As
things heat up a bit more, the needle is now only slightly optimistic so
that 200 actual water temp. reads a bit below 210 or so on the gauge (or
just about one needle thickness to the right of the actual temp). Not
bad. By the way, I'm using a 160 degree thermostat.
I had to drive to downtown Los Angeles today (about a 40 mile round
trip) and this is the first time I've ever been glad I hit stop and go
traffic as it gave the gauge a good workout. It wasn't that hot a day
(75-80) but still warm enough. It turns out that I am pretty lucky and I
have a very cool running Tiger. In dead stop traffic (stopped for three
minutes+ at a time, temp. never got above 205 or so and as long as
every minute or so I moved a bit, it didn't get over 190-195. Normal
running temp., it turns out, is barely over 170 degrees at speed and
moving at just 10 mph or so gets me about 185-190. It sure changes the
way you look at the temperature gauge and makes the drive a lot more
fun. No more needle heading toward 250! The moral of the story, as
others have said before, is before you spend a lot of money trying to
solve a cooling problem, make sure you actually have one first. I was
almost ready to plunk down the big bucks for a new radiator, so I've
saved quite a bit with my two nights of work.
Steve Sage
1967 MK1A
|