Cycling the Glow plugs in cold weather

Ok so I know that our piddly 20 degree weather makes you Canucks snort, but for me, and apparently my NB, it is DAMN cold.

I just filled up this weekend with, what I believe to be winterized fuel, but I also added a more than generous dose of the white Power Service. Or was it Diesel Kleen? Either way, it was the winter mixture.

This morning was the first truly cold morning we've had this winter and since I got my TDI. The glow plugs went on and stayed on for a few seconds; rather than starting the car, I cycled the glow plugs again and then turned the key all the way. She started, but it was ROUGH.

Is there any benefit to cycling the glow plugs? If not, is there anything I can do besides installing the TDI Heater that would make the morning starts a little easier on my engine?

TIA

Rough starts in cold weather have always been the norm for me. When I lived in Detroit, the winter starting temps would often be in the teens. There would be white smoke and a little shaking at times but I simply drove away gingerly. 117K later, it's doing fine. And.. Of course there is a benefit to cycling them, (that is waiting for the light to go out, not turning the key on and off prior to start)... or they wouldn't be there.

Advance your injection timing.

Cycling the glow plugs won't help retarded timing other than just wearing down the battery and slowing the cranking speed further making start even slower.

DB

Can you advance your injection timing on a PD?

No.

Don't worry about it. Let the glow plugs cycle, then crank. I agree with SoCalJames - they're not happy about starting when they're cold, but they always do and they get over it quickly. 134k and 6 Wisconsin winters on mine & I never had a no-start.

Research on this topic has revealed the following:
These glow plugs heat up to full temperature within a second, unlike the old style glow plugs.. So cycling is pointless on these newer tdi's. After the glow light goes out, try waiting a second or two seconds then crank. (When the glow light goes out, the plugs are still activated)

Sounds normal cold-weather diesel starting to me. It was 8F here this morning and the TDI didn't like it too much, but the shaking and smoke won't hurt a thing. Heck, I've started the TDI at -18F once the glow plug light went out and it started right away...with smoke and shaking.

Now starting up the Powerstroke at that temperature is quite a different story. Probably should get around to plugging (block heater) that huge hunk of cold metal in at night.

One trick recently talked about here was to wait about 10 seconds AFTER the glow plug light goes out before starting the car. I have tried this 3 different days now and it REALLY seems to work much better than cycling the glow plugs. Perhaps it's just my imagination???

The waiting a few seconds after the glow plugs went out provided a smoother start than yesterday's cycling. It was about 5 degrees colder this morning than yesterday and the Beastly Beetle was definitely happier today.

Now if only *I* had glow plugs to get me going in the morning

Actually, once I thought about it, it makes some sense. After the glowplugs have 'fired', if you give some time for the heat to migrate into the head a bit, it just might help starting the engine.

Think about it this way- the plugs stay on after the light goes out, even after the engine is running. If you wait longer before cranking, it helps warm the combustion chamber. If you "cycle" the plugs (turn them off and on again), all you're doing is turning off the power to the plugs momentarily. How does that help warm the combustion chamber?

The plugs are still energized after the light goes out.

To get the full benefit of the plugs, wait until you hear the GP relay click back open before cranking it.

11 degrees in DC. The Jetta didn't seem to like waking up at 3:30 to that. Can't say I did either. Normal cold diesel start: Rough and loud...

My glowplug light stayed on for about 7 - 8 seconds this morning. It's never been that long. It started pretty rough, but after a few seconds it calmed down. Now I have a CEL. I'm thinking it's the glow plugs. Any thoughts? It's a 2000 Jetta, bought used last spring.

B5V, TDI at 7 deg F, this morning. Glow plug light stayed on at most 5 seconds, and the engine started without hesitation, a bit rough for the first minute. Compared to my first diesel, a Mercedes 220D, which required a 60 sec preheat under the same conditions, the new TDI engines are sweet.

Well this morning was 10 degree w/30mph wind gusts

Glow plugs came on as stayed on for about 10 seconds. I then waited another 10 seconds or so and she didn't start So I turned off and started the whole process again. The second time was the charm, but it was ugly.

I don't know how you people who live where it is like this all the time make it without a TDI heater. I had a hard time even shifting gears until the car warmed up some! I am glad though, that I took the time last weekend to buy the winter Power Service, otherwise who knows what would've happened this morning.

I would think that the best time to crank would be when the glow plugs were still actually glowing.

Wouldn't the diesel fuel ignite better when compressed in the vicinity of a red-hot glow plug...?

Maybe that's why the glow plugs continue to glow for a short time after the indicator light on the dash has gone out - because that's when the driver is expected to be cranking the engine.

Thoughts...?

I think that the glow plug light is kind of an "idiot" light for the non-enthusiast. It is a reminder to wait a bit before turning the key to start.

For both our vehicles, I wait a corresponding amount of time AFTER the glow plug/wait to start light goes out depending upon hold cold it is.

40-30F - turn key immediately after light goes out
30-20F - turn key about 10sec after
20-10F - turn key about 15sec after
10-0F - turn key about 20sec after

and so on.

Keep in mind also that the glow plug light itself will be on longer as the temperature drops.

The whole key is to have a battery (large enough) in good condition. Second - there's a reason 5W40 oil is specified (although I wouldn't hesitate to use 0W40 that met all other requirements).

Keep in mind - these WILL start in Artic conditions if you have a good battery and proper oil, it's just a matter of following proper procedure.

Four new Bosch glow plugs at 55K - -2.7'F the other morning and - one thousand one - one thousand two - one thousand three after the glow light goes out and it starts like it is summertime (having a belly full of Wacker 50 cetane Amoco Premier don't hurt either ).

Now if only *I* had glow plugs to get me going in the morning

Click to expand...

Now where would you put an electrical probe like that...

If he was an Iraqi, he could pretend he was being interrogated with lit cigarettes and stick them in his ears...