Hot V6 alfa-digest V7 #899

["C.M. Smith" <cmsmith@domain.elided>]

Cooling systems benefit from regular and routine maintenance, from new!
That's often the problem, particularly if you don't know the service
history of your car. New owners routinely do a tune up and oil change when
they first acquire a vehicle but forget or don't realize the importance of
the cooling system.

 The cooling system is ignored by a lot of owners precisely because it
works flawlessly until it starts to clog. Aluminum sacrifices to iron and
steel, galvanically speaking, creating most of the crud you see in a
cooling system. Plain water is bad in a cooling system, as is plain
water/glycol without additives. These additives include a sacrificial
electrode, in essence, which saves the aluminum but does so by being
steadily consumed. About one year for cheap coolant (never use this in an
Alfa, you'll regret it) and two years maximum for good coolant (yeah yeah I
know there's five year coolant and long life coolant out there but why?
regular flushing of the cooling system is so beneficial why bother with
long life coolant?).

I flush the system and change the coolant every two years. I check the
hoses regularly and when they start to go I generally just do them all at
once. The labour to change one is not a lot less than the labour to do them
all once the coolant is drained. They last about ten years so unless you're
planning to keep the car for forty years there's not much to save by
replacing only the hoses that are obviously bad (hoses often decay from the
inside and detection of a bad one can be very hit and miss).

I also replace the thermostat if there's the slightest doubt about it
working properly. Most start to stick open and the engine is slow to heat
up and will cool noticeably on long downgrades. Unfortunately, they tend to
lose their ability to open all the way as they start to stick open. There's
no way to test a thermo without removing it, why put a suspect one back in?

Result? one pinhole leak in a rad hose on my SAAB turbo (at 12 years and
200,000 km) which did not disable the car, I drove it to the mechanic to be
fixed. Never had an engine boil over or even overheat. Never had to rod or
replace a rad or heater core. Before I learned that coolant mixes have a
service life of two years max (by reading the owner's manual!) I had no end
of cooling aggravation, including a bad rad on a 78 SAAB 99  many years
ago, which I now believe was due to inadequate servicing.
Michael Smith
Calgary, Alberta
Canada
91 Alfa 164L, White, original owner 

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