Thermostat or Water Pump

[Bixxer Bob]

These engines are aluminium alloy Sevvy, the radiator too. Not sure why you'd get rust in there although I follow your logic for old cast iron engines in cars, trucks etc.

[ssevy]

Hmmm..my overflow tank had brown rusty fluid in it when I bought it. Must be from some other cause? Well, take thatone off the list of possibilities I guess

[Mustang]

shhhhh .....the liners are steel and guess what they sit in ? 

[97tiger885]

Took a trial ride today.  The gauge behaved itself quite nicely.  Looks like  the Tiger thermostat was worn out.  Wont know about the overheating in stop and go traffic until temps go back up.

[Bixxer Bob]

shhhhh .....the liners are steel and guess what they sit in ? 

Doh!     

Sometimes you can overlook the obvious if you overthink it.  That's why I'm always saying, simple stuff first.

[Sin_Tiger]

shhhhh .....the liners are steel and guess what they sit in ? 

had several Rover V8s (derived from a small block Buick) although it was all alloy they used to suffer from build up of sludge in the bottom of the radiator. This was exacerbated by the engine being a big lazy lump rarely got stretched meaning the engine driven water pump wasn't running at optimal speed and many cooked engines ensued blamed on a whole menu of issues designed to swell the bank accounts of many workshops.

End of the day,  regular flushing and use of a good quality additive to maintain the nitrate levels is the best option,  just make sure you choose one that has alloy inhibitors built into to the additives.

[97tiger885]

Rode to breakfast, 25 miles each way, in high 20s F.  Tiger warmed up faster than it has been doing recently.  Definitely had a thermostat problem.

Bixxer Bob
That's why I'm always saying, simple stuff first.

You want simple?  I didn't realize the Tiger had a thermostat until I took the radiator off the Trident and saw that the Trident had one.  That is simple.

[Sin_Tiger]

That's good to hear, far better than another "head off" thread