DeTomaso Mailing List: May 1997, Message #213
     



From: MikeLDrew@aol.com

Subject: Re: Temperatures

Date: Thu, 8 May 1997 04:31:47 -0400 (EDT)



Capt Mike Drew

150 Westgate Dr.

San Francisco, CA  94127



Home:   (415) 334-7860



E-mail:  MikeLDrew@aol.com





All,



Don Franck wrote:





In looking back at past notes on temperatures that people see in

traffic, they are reporting 200 or so on the high end.



I have been running about 210 in light traffic on cool nights, but that

is a reading off of the block on an extra gauge.  My experience is that

I boil over at about 240-250 on the extra gauge.



The original gauge with the very few appears to only read about 180. and

never moves a great much.  What's the deal?



Are the temps other report off of the original gauge?







>>>This has been a bugaboo of the Pantera for years; the Italian gauges take

data from U.S. senders which are not compatible, so the readings are only

relative (i.e. your oil pressure is 'high' or 'low') but the numbers may not

be accurate.



The Pantera's temp gauge traditionally used to read higher than actual

temperature, causing panic among owners when the cars were new.  The factory

'fix' which was in a Ford TSB was to place a resistor or two in-line between

the sender and gauge to bring the reading down.  (Later cars came with a

gauge reading to 260 degrees instead of 230; the same temperature reading was

considerably further away from 'max' and thus owners were further placated.)



For those of you without mechanical gauges, here's how to test your gauge:

Steal your wife's meat thermometer when she's not looking, remove your

pressure cap and place it in your radiator supply tank (the full tank, not

the half-full one.)  Secure it so it can't fall in, start the car, and let it

warm up.



As it warms up, compare the reading on your instrument panel with the actual

temp as registered on the thermometer.  If they're not the same, and if you

care, plan on getting friendly with an electrical expert soon!  (Since

coolant is extremely poisonous, make sure you wash the thermometer carefully.

Since it's apparently tasty too, if you're a little careless about the

washing-off part of this job, don't complain if your wife's next roast tastes

a little funny.)



By the way, Panteras were originally wired with the temp gauge sender on the

radiator tank, not the engine.  This is dumb.  It tells you the temperature

inside your tank.  Who cares about your tank?



Back in the days of my youth, in the few months that I actually DROVE my

Pantera in complete and profound ignorance, I became a living testimonial as

to why it's a bad idea to leave your car wired like this.  I was humming down

the road enroute to Jack DeRyke's house (an hour south) to attend to some

other impending catastrophe when I noticed my water temperature gauge

starting to climb.  As the car tended to run extremely hot anyway, I didn't

have a lot of room to play with.  It got hotter and hotter, and I became more

and more worried, to the point where I actually contemplated slowing down.

Then, the gauge started to slowly drop back down towards its NORMAL too-hot

reading, so I began to relax.



Then I started to hear pinging.



Hmm, the engine never pinged before, I'm just cruising along, I wonder why

it's doing that?



Then, I happened to glance in the mirror and saw the steam pouring out the

back, and decided that perhaps investigation was in order.



It became very obvious when I removed the radiator cap and was greeted with a

scalding rush of steam that burned my forearm somewhat severely that I was

now out of water.  What was not obvious was why.  As far as the temp gauge

goes, what had happened was that the temp sender was first reading the

temperature of the water in the tank as it became hotter and hotter.  Then,

when the water level dropped below the level of the sender, it began reading

the temperature of the STEAM, which was hotter still.  When even that tapered

off, the temp of the air in the tank was lower and the needle started to

drop, even as engine temperature continued to skyrocket.



I was stuck by the side of the road, walked a mile to the nearest phone,

called Jack and he wasn't home.  His son Mike came and rescued me, driving a

Corvair with giant water cans in the back.  We refilled my system, I started

the car, it seemed fine.  I drove behind Mike for several miles, and when my

temperature started to climb I zoomed off the freeway into a gas station,

re-filled and pressed on.  After three re-filling stops I made it to the

DeRyke place, crawled under the car and discovered the hose clamp from the

water pipe to one of the hoses had come loose, the hose was only resting

against the water pipe, and thus was leaking like a sieve.  (This, of course,

was discovered only AFTER purchasing new hoses under the assumption that the

old ones had broken!)



The fix?  There's a temp sender located on the front of the engine block

(near the water pump, I believe) and that's the one that should be used.

Then you always know the temperature of the ENGINE coolant, and can respond

with the appropriate degree of panic when it starts to hit the red zone.



(As an aside, after I re-wired my gauge per the above, the car ran only a

fraction below the red zone, even during long stints of highway cruising in

cool temperatures.  Based on what I'd heard and read about the mismatch

between Italian gauges and U.S. senders, I smugly assumed my gauge was wrong.

Then, I pulled into Oklahoma City and got stuck in traffic, the gauged moved

just ever so slightly to the right, the needle actually TOUCHED the red zone,

and the car erupted like Mt. Vesuvius!  This problem has hopefully been fixed

by simply getting a new radiator and new fans and new hoses and new hose

clamps and new fan mounts and new relays and a new fan switch and a new water

pump and new water pipes and new temperature senders.  See?  Fixing a Pantera

is as simple as that...just throw money at the problem as much as you can

stand it, and that should make it go away.  Right?  Please?)



Mike