My W124 M102 ('92, 100k miles) is losing coolant, about an inch every
weeks or so in the reservoir. Replaced a couple of hoses that were
dripping a bit,
and the reservoir cap. Now there is no visible exterior leaks from the
Also changed coolant and flushed the system, including the heater
core. Still losing.
In addition, I've noticed that the loss is greater when the car has
running in stop and go traffic, at 100 - 110 ºC. There is almost no
during highway trips with the Tº steadily at 80 ºC.
My last hope before start thinking about head gasket is that the loss
the water pump bearing. The car has a clicking noise coming from the
when starting cold in the morning, which disappears completely after a
I tried a mechanic's stethoscope on the pump, but the test wasn´t
the alternator's bearing could be the noisy one.
Aside from the coolant loss the car is almost perfect. It has good
a 4 cyl.), idles smoothly, no oil or fuel in coolant, no coolant in
no white smoke from the exhaust. Also, all the spark plugs look fine,
with a normal
Is there a better way to diagnose the pump? Should I change the pump