Sort of a no-story,  story. But what the hey.

When I bought this '86 syncro the coolant temp needle would sit just  on the upper half of the LED. I replaced the tstat with, yes, a Meyle 87C unit. The original was a Wahler  with a 1985 date stamp on it, was prob. original. Well the new tsat made no difference in where the needle lay. This was not a big deal at all. About a year or so later I replaced the radiator. No change in temp needle behaviour.

All was hunky dory until this year when I noticed that the needle was creeping up, sitting above the led. When I had the engine out for head replacement I did a casual test of 3 tstats I had - the Meyle, the original Wahler, and a BTT (Behr I think). They all seemed to move the same amount in the hot water test so I popped the Meyle back in.

Last logging road trip caused me to think that something was wrong though. On those roads you often have to climb bumpy hills in first or even G gear. So you have highish rpms and low airspeed through rad. I noticed the rad fan come on much more often than it has ever done before on similar roads (well, even the same roads last year, same weather etc).

The needle was now sitting with space between it and the LED. It would sit there pretty steady, when driving at 80 kph, about 25C ambient temp. Oil temp would be 100 - 105C. But there was not much "headroom" till the fan came on. And the fan was coming on more often than I have ver experienced before.

So I swapped in the BTT unit. Now the needle sits on the LED (on the low side of middle) when driving at 80 kph, 25C ambient. Oil termps now 95-100C. Needle will creep up in stop and go traffic after hwy run, but just the way it should be.

alistair