ned kleinhenz wrote:
Most of the glow plug threads seem to involve a lot of discussion about
isolating a bad glow plug to replace it.
When I have glow plug problems, I always start by sending Rusty $60+/- for a
whole new set, then installing them. This is because I only have to replace
them once every few years and many 10's of 1000's miles. In more than 20
years of driving MB diesels, I have never had a random failure of a young
glow plug. Is that common occurance, and I'm just lucky not to experience
it? Or do most glow plugs last almost forever, and all I should really
need to replace is one or two that go bad?
I'm always ready to learn a better way.
If the engine is running well, glow plug problems with older (pre 1990)
engines seldom occur before the engine has 100kmi and many lasted closer
to 200kmi. As post start glow was implemented however, glow plug "on
time" increased so the life of the plugs (measured in miles driven)
decreased as the duration of glow plug "on time" increased.
For a mid '90s or later Mercedes diesel car, largely only driven in city
cycle to and from work and a few shopping trips a week, the glow plug
life might only be 40-60kmi while one that was driven more than 100
miles for every cold start might get 150,000 or more miles before the
glow plugs began to fail (providing poor idle problems were addressed
promptly).
Glow plug life is largely a function of how long the plugs are energized
for each start. In the older engines the AVERAGE time the plugs were
energized seldom exceeded 10-20 second while with the newer engines that
time may be extended by a factor of 10! Even with much more durable
plugs, the life of the plugs is MANY fewer miles.
Marshall
--
Marshall Booth Ph.D.
Ass't Prof. (ret.)
Univ of Pittsburgh School of Medicine
[EMAIL PROTECTED]
