I believe I have had every overheating problem in the universe on TR6s. If
you think your rad is not completely shot then it sounds like the dreaded
head gasket leak to me. You get steam in the water pump and it stops moving
the coolant. Then as the steam expands the coolant is pushed out of the
system.
Does it overheat faster with the cap on? That is a good indicator. With the
cap off the movement of the coolant can carry bubbles out of the system when
passing on the top of the radiator.
To be sure, remove the thermostat and run car. If with new pump, no
thermostat and rad uniformly warm and it still overheats then you are
beginning to run out of alternatives.
I put in a new rad core, thermostat and pump. Now I run at just below 3/8
when standing still in traffic. Slightly less on highway speed for long
runs. Too low really, I want to test my sender.
I really hope it is your thermostat or rad; I hate doing head gaskets.
Cheers,
Mark Hooper
72 TR6
-----Original Message-----
From: Timothy Holbrook [mailto:tjh173@yahoo.com]
Sent: Monday, August 13, 2001 3:35 PM
To: 6pack@autox.team.net
Subject: Re: Overheating - HELP!
Just wanted to thank everyone for their input and advice.
Unfortunately the car is still overheating. I was forced to drive my
Civic to the TRF party!
I replaced the water pump to no avail. Car still overheats after about
20 minutes of driving. Next morning, I ran the car from cold, idling
at 1500 rpm, electric fan running, rad cap off. At 1/4ish on temp
gauge, 160 degree thermostat opened and flow occured in rad. Car
progressively got hotter up to about 1/2, which is to be expected
considering the incredibly hot ambient temps. Then rad flow seemed to
slow down and stop. Car got hotter and hotter. Still no rad flow,
water began to come out the top of the rad. So I shut off. Seems to
me that I've got a blockage somewhere. Maybe a hose that collapses
with heat (however, I can't see it visibly anywhere), or some clog
somewhere. Not really sure. Anyway, I bought new rad hoses at TRF.
Will remove the rad and have it boiled out and pressure tested. Will
also backflush the heater core and the engine.
Unfortunately, this will have to wait a bit. I need to get a storage
garage for the TR6, my fellow apartment complex dwellers seemed less
than impressed when they found a grease covered guy pulling out a water
pump in the parking lot last week! I don't want to get kicked out!!
One quick comment regarding the temp gauge. My car always runs at 3/8
or so. This has remained constant through 2 sending units and 2 temp
gauges. I ran with a mechanical gauge for a while, and the car always
ran around 180 degrees. When my 160 degree thermostat opens, the car
reads about 1/4 on the gauge. All these readings were confirmed with
other TR6 owners this weekend at TRF. If some of you are running
around 3/4 routinely, you may want to put in a mechanical gauge for a
while to see what it reads.
Tim Holbrook
1971 TR6
--- bob <rmf3860@erols.com> wrote:
> Tim:
>
> I can't offer more than Sally and Dick Taylor as to possible reasons
> why
> you're running hot, but I would like to comment on what you said was
> "normal" temperature for your car.
>
> Motorhead is a Triumph garage in Northern Va. They have a good
> reputation and offer a catalog of parts, advice and diagnostic
> guidance
> to help solve problems and symptoms. According to their literature,
> our
> cars (I have a '75 Six) should run between half and three quarters on
> the temperature gauge. Mine runs at just a needle width under half
> and
> creeps up to half and slightly higher in summer stop and go traffic.
> If
> yours is running at less than half, the temperature sending unit may
> have to be replaced. You mentioned that yours runs at 1/4 to 3/8. One
> way to further check the temperature gauge is by grounding the
> sending
> unit wire. If the gauge goes to hot, the sending unit may need to be
> replaced. A new unit is about $3.
>
> Please let us know what you find out.
>
> Bob Fabie
> Fredericksburg, Va
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