Steve,
I have been wrestling with overheating on my Tiger since the day I bought it
last October. It wasn't until I drove to Tigers United with a New radiator
and still had trouble that I really recognized that I had serious problem.
My symptoms were a loss of coolant over a period of days, and my add on
overflow tank would fill up completely even when the temp never got above
200. ( My gauge has been checked against a thermocouple and DVM and it in
agreement within 3 degrees.)
My problem progressed until I could see bubbles in the overflow tank. A
trip to the smog station confirmed that I was getting combustion gases in
the radiator.
I pulled the heads and had them inspected. Found a crack in one but the
crack went between the spark plug and the intake valve. So I don't think
that was the source. I bought heads and had a valve job done.
While putting the whole thing back together, I found evidence that one of
the freeze plugs was weeping. The PO used steel core plugs, then chose to
run pure water instead of coolant. GRRRRRRRRRRRR!
I never saw any evidence of coolant on the ground under the tiger BUT it was
very clear from the rust and missing paint on the block that one freeze plug
was weeping. This could be a source of your coolant loss.
While I had the whole car apart I installed a new fan. I bought the Derale
17015
fan that was mentioned in the TE/AE article on Tiger cooling. This fan has a
huge amount of twist in the blades. Also most of the blade is behind the
mounting hub. This means the blades stick out of the fan shroud the way it
should. I actually had to make a spacer the moved the fan closer to the
radiator so the blades would not hit the fan belt. The spacer meant I did
not have to bore a 1 inch hole in the fan. It sits on the 5/8 inch water
pump shaft.
I did not have to trim the ends of the blades at all. I have 3./4 inch
clearance with the rack. (I have the thick washers between the motor mounts
and the block.) The only mod was to take the lower ends of the fan shroud
and pull them towards the engine block. This created enough clearance for
the fan.
The only down side to this setup was the fan blades hit the upper radiator
hose.
I was using the stock shape hose I bought from SS.
I found a different shaped hose from Napa. By using a portion of this hose
and a portion of the stock hose I was able to route the hose up and over the
vacuum advance unit on the distributor and then over to the radiator. I
joined the two sections of hose with a GANO filter.
Now that all this is done, I have noticed several things.
1. The stock header tank is always completely full to the neck when cold.
2. My home made overflow tank has some water in it when cold. When fully
warmed up it is about 1/2 full. I used to get completely full. My
overflow tank is a 1 quart rectangular Nalgene bottle I bought from REI.
3. In town the car will run 170 to 185. (I have a 160 thermostat since the
heads went back on).
4. When on the interstate at speeds above 70 it will run at 185 for about
10 miles and then it will fairly quickly move up to 200 and then stay there
until I slow below 55.
I guess this is a long winded way of saying that losing coolant is not
normal. Find the leak and your problems should go away. Crawl under the car
and check the freeze plugs.
Erich
----- Original Message -----
From: "Steve Sage" <ssage@socal.rr.com>
To: <stubrennan@attbi.com>; "Tiger Mailing List" <tigers@autox.team.net>
Sent: Saturday, November 09, 2002 7:18 PM
Subject: DUH! on me
> Stu Brennan wrote:
>
> >I think it's unlikely that the radiator suddenly clogged to cause your
> >problem, especially in the "cool" weather you describe, and with the
> >Gano. My guess would be a failing thermostat. The slow warmup would not
> >happen if the Gano was clogged. Does it seem to stabilize for a bit at
> >your normal thermostat temperature, or does the gauge just continue on
> >upward? A pause would indicate some thermostat activity, but if it just
> >continues up without stopping, then the thermostat may be frozen.
> >
> >When my heater core leaked, I had green water dripping down by my
> >passenger's feet. As for anywhere else it might be going....How does
> >your oil look? Is the quantity going up?
> >
> >Stu
> >
> Stu and other Sunbeamers:
> I think the temp. does, once it starts rising, pretty much just go up to
> 200+ a bit. However, I must now pronounce myself officially "Sunbeam
> dumb"! I just checked the water level in the header tank and it was way
> down, the obvious immediate cause of it running hot. Why I haven't done
> that for the last few days is beyond me. I've just been adding a bit now
> and then to my extra overflow tank, which obviously wasn't functioning
> correctly since it didn't have enough water from the system to work
> with. Maybe it's the onset of Stevesheimers disease or something. The
> oil, by the way is clean and no evidence of water there. Sooo, the water
> is obviously going somewhere. I decided to just get on with it and I'm
> pulling the radiator, header tank and heater core tommorow and take them
> to a radiator shop on Monday to have them tested and fixed where needed.
>
> Which brings me to my fan shoud question, since it will be coming out
> too. I have a stock fan shroud. The fan blades in my Tiger reside
> completely inside the shroud. I understand that for the shroud to be of
> benefit, about 1/3 of the blades should be outside the shroud to pull
> the air through. Short of having a custom shroud made (which I may do
> eventually) would I be better off just running without the shroud in its
> current configuration? Or will that make it run hotter?
>
> Steve Sage
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