In an effort to keep the Boston Bob engine in my workhorse daily
driver alive forever as a monument to his art, I'm trying to solve
this new potential problem in a timely manner. I'm seeing higher than
usual temperatures at idle lately. Radiator, hoses, thermostat are
less than 3 years old, changed with the engine. Water pump was
installed new on the previous engine 6 months before it crapped out.
Symptom specifics: normal temps on the road, but at idle the needle
rises farther above LED than usual, and when the fan comes on it stays
on much longer and the needle drops much slower than previous. Opening
the heater valve at idle and turning on the fan brings a slightly warm
breeze, giving it a little gas and bringing the idle up to 1800-2000
turns the breeze to a scalding blast that feels like it could blister
paint. I think I've pretty much narrowed it to a coolant flow issue!
Is this a failure mode of these water pumps?

--
John Bange
'90 Vanagon - "Lastwagen"
'90 Vanagon GL - "Wiesel"