Mike Canfield wrote:
Steve,
The only reason I quit driving it was because it used nearly as much oil
as it used fuel........Running my WVO blend offset the cost but eventually
it just got to the point where I was sick of buying oil. I just figured it
had 320K miles on it so it deserved to use oil..LOLOL
Glad you are enjoying the ole Gal....I sure did and it was the best used
car value for me as well.....I drove it for over a year after buying it on
E-Bay for $500 with no pics and the owners word that it would drive anywhere
I wanted to get it home WITH his tags to send back.
Several points about cold weather and starting. If compression is low,
the engine will be hard to start or may not start at all. Dave Quay who
used to run Atlanta-Stuttgart (the Tiffanys of Mercedes recyclers) used
to say that once compression was below about 320 psi (22 bar), an engine
could not be counted on to start reliably in cold weather. As
temperature drops, staring becomes more difficult as leakage around
rings and valves increases. This can be due to wear, or it can be due to
carbon accumulation. A badly carboned engine will NOT seal and so will
start poorly (or not at all) when the temperature drops, just like an
engine that worn. If the carbon can be dissolved and burned out (Mobil
synthetics can usually do it in 10-20kmi) the engine will often resume
starting reliably in cold weather - IF NOT TOO WORN. NO oil will reverse
wear!
Valves USUALLY inhibit cold starting by a slightly different mechanism.
The valves and the engine head are made from metals with VERY different
coefficient of expansion/contraction with temperature. As the head
assembly cools, it contracts more than the valves contract so at some
point, the valve starts to hang open. When intake valves are properly
adjusted (0.10 mm) they will not start to hang open until temperatures
approach zero (F). If temperatures below zero are anticipated, the
clearance should be increased to 0.15 mm to insure that the valve(s)
don't hang open. Intake valves USUALLY end up with decreased clearance
as they wear (I know, that's counterintuitive). When the valve are a
little too tight, there will be some temperature at which they start to
hang open. That will be an almost all or none affair. At one temp the
engine will start fine and at a temperature only a degree or two lower
it won't. This usually doesn't present a problem until temps drop below
freezing.
Marshall
--
Marshall Booth (who doesn't respond to unsigned questions)
"der Dieseling Doktor" [EMAIL PROTECTED]
'87 300TD 182Kmi, '84 190D 2.2 229Kmi, '85 190D 2.0 161Kmi, '87 190D 2.5
turbo 237kmi
