Glow Plugs

What are the symptoms of a blown glow plug in a TDI engine? (1999.5 Golf
TDI, 1.9L 90Hp) - Should I see the glow plug light coming on while driving,
or flashing? (does neither)

My glowing period in these really cold winter days is getting to be (seems
like) close to 20 seconds, and I leave the car plugged in all night (now, it
could just be the block heater has a bad connection, but it's only been in
use 1 1/2 winters - I'm going to get my clamp on amp-meter out and test for
current using an intermediate connection between the extension cord and the
plug on the block heater where the hot wire can be separated from the others
for the purpose of testing current, but lazyness and it being -30°C out have
stopped me from doing this test (haven't made my special extension cord for
doing test either...) of the heater)... When the car fires it sounds like
one cylinder is "coughing"/sputterings for a a little while before it
catches and runs smoothly... this might just be the very cold weather we've
been having tho.

It will turn the MIL on if there is a glow plug issue. But, it's possible
that when the car was new some technicians would change the glow plug wiring
if they couldn't fix a MIL problem.
The best and only GOOD way to check them is measure the current on each glow
plug. Should all be near equal and around 11 amps each.

"Rob Guenther" > wrote in message
...
> What are the symptoms of a blown glow plug in a TDI engine? (1999.5 Golf
> TDI, 1.9L 90Hp) - Should I see the glow plug light coming on while
> driving, or flashing? (does neither)
>
> My glowing period in these really cold winter days is getting to be (seems
> like) close to 20 seconds, and I leave the car plugged in all night (now,
> it could just be the block heater has a bad connection, but it's only been
> in use 1 1/2 winters - I'm going to get my clamp on amp-meter out and test
> for current using an intermediate connection between the extension cord
> and the plug on the block heater where the hot wire can be separated from
> the others for the purpose of testing current, but lazyness and it
> being -30°C out have stopped me from doing this test (haven't made my
> special extension cord for doing test either...) of the heater)... When
> the car fires it sounds like one cylinder is "coughing"/sputterings for a
> a little while before it catches and runs smoothly... this might just be
> the very cold weather we've been having tho.
>

Rob Guenther wrote:
> What are the symptoms of a blown glow plug in a TDI engine? (1999.5
> Golf TDI, 1.9L 90Hp) - Should I see the glow plug light coming on
> while driving, or flashing? (does neither)
>
> My glowing period in these really cold winter days is getting to be
> (seems like) close to 20 seconds, and I leave the car plugged in all
> night (now, it could just be the block heater has a bad connection,
> but it's only been in use 1 1/2 winters - I'm going to get my clamp
> on amp-meter out and test for current using an intermediate
> connection between the extension cord and the plug on the block
> heater where the hot wire can be separated from the others for the
> purpose of testing current, but lazyness and it being -30°C out have
> stopped me from doing this test (haven't made my special extension
> cord for doing test either...) of the heater)... When the car fires
> it sounds like one cylinder is "coughing"/sputterings for a a little
> while before it catches and runs smoothly... this might just be the
> very cold weather we've been having tho.

That is not an indication of a bad glowplug. Unless they have changed
things the glow plug is timed based on a temperature sensor. I don't think
it is water temperature, so it may be missing the fact that you have a block
heater. I really don't know, but in any case it does not wait for the glow
plug or engine to get to any given temp. If it is below 40º F it will turn
on for X seconds, if below 10-Xº it will be X+Y seconds etc.

If your glow plugs are bad, it will not start or it will start and since
not all the cylinders will be hitting right away it will run rough for a few
seconds. Generally if you disconnect the glow plug it the connection to
ground should show open if it is bad. I would not bother testing what you
have however as I appears they are OK

The plugs on my old rabbit lasted over 180,000 miles until my ex totaled
it.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

"Woodchuck" > wrote in message =
...
> It will turn the MIL on if there is a glow plug issue. But, it's =
possible=20
> that when the car was new some technicians would change the glow plug =
wiring=20
> if they couldn't fix a MIL problem.
> The best and only GOOD way to check them is measure the current on =
each glow=20
> plug. Should all be near equal and around 11 amps each.
>=20
>=20
Have you ever seen a 'soft' failure of a glow plug... where it will show =
continuity but not heat? (Curiosity)

I have found that one bad glow plug will not trigger the MIL, but two =
will. Altho, my car seems to be an abortion according to the wiring =
diagrams my car should not have a load sensing glow plug system, so who =
knows?

Block heater for one hour will cause it to be warm enough to have a =
very short or no glow cycle but run rough, while three hours in any =
conditions will short cycle or no cycle (glow lamp comes on for less =
than a second, as in summer) and engine will start smoothly. If you are =
getting a 20 second glow at=20
-30C your block heater is most likely not working. Also, if you are =
getting temps that cold, you might want to add a 40W oil pan heater, oil =
pressure comes up faster on cold start.

--TW