Cold starting

[bigred]

Since the cold weather set in the Superb (1.9TDI 130) seems rather reluctant to start in the mornings and if it's been stood all day. I'm leaving the ignition till the glow plugs light extinguishes but it is still very lumpy for around the first five seconds and there seems to be a lot of blue smoke. After this period the engine runs perfect. Anyone have any ideas?, new glow plugs required :confused: or is it something else

Mark

[dieselV6]

Most likely it's the glow plugs, check resistance with an ohmmeter, should be below 1.5Ohm each.

If any of them stands out (e.g. 2 Ohm or more), replace the lot. It's not worth waiting

If all glow plugs work fine, check also that you get the voltage on them after turning the ignition on. Best to leave 3 plugs connected to the harness and check voltage on the 4th harness socket. If there's no voltage, glow plug relay is gone or the harness is damaged.

Hope this helps

[Bluefox]

Most likely it's the glow plugs, check resistance with an ohmmeter, should be below 1.5Ohm each.

If any of them stands out (e.g. 2 Ohm or more), replace the lot. It's not worth waiting

If all glow plugs work fine, check also that you get the voltage on them after turning the ignition on. Best to leave 3 plugs connected to the harness and check voltage on the 4th harness socket. If there's no voltage, glow plug relay is gone or the harness is damaged.

Hope this helps

Diesel, would that cause the blue smoke?

I didn't realise that unburnt diesel would cause blue smoke, I thought it was just motor oil...

[Gizmo]

I didn't realise that unburnt diesel would cause blue smoke, I thought it was just motor oil...

It won't, you are right.

White 'smoke' = water, clouds of it means a blown head gasket (small amounts is just condensation from a cold engine - this disappears when the engine is warm.

Blue smoke = burning oil, normally from either valve stem seals or worn piston rings.

Black smoke = unburnt fuel

The above applies to diesel and petrol engines.

[Bluefox]

It won't, you are right.

White 'smoke' = water, clouds of it means a blown head gasket (small amounts is just condensation from a cold engine - this disappears when the engine is warm.

Blue smoke = burning oil, normally from either valve stem seals or worn piston rings.

Black smoke = unburnt fuel

The above applies to diesel and petrol engines.

I thought so, thanks Gizmo.

Could this possibly be due to failed turbo seals, as well? Also, would the sticky vane problem cause leakage?

Thanks though, you've just won me an argument at work

[Bluefox]

Since the cold weather set in the Superb (1.9TDI 130) seems rather reluctant to start in the mornings and if it's been stood all day.

I've just re-read the OP's post and as it seems to only happen when the car's been stood I'll put money on valve guides or over filling of oil.

How many miles you done?

[dieselV6]

Missed the "blue" bit in the smoke, sorry.

The original point being, if glow plugs are worn out/gone, you get a lot of smoke on startup and hard cold starts.

I agree if the blue smoke persists it could be the rings, oil seeping in, etc

However, I'd still check the glow plugs and oil level first. Why? Because it takes <5mins and a multimeter+cloth to do and all other things mentioned take at least half an hour to get to and a set of tools. And because over small amounts of smoke, the colour is subjective.

When my Superb had a hard start problem (2.5TDI V6, problem with injection pump set too late, easily fixed by setting timing to earlier), I was getting a lot of smoke after <2s cranking.

I always thought this smoke was white-grey, even though it was pure air+diesel mix (so should be black). Unless it caught condensation on the way out.

[Gizmo]

Could this possibly be due to failed turbo seals, as well? Also, would the sticky vane problem cause leakage?

Yes it certainly could, although with the turbo seals you know what has gone as it belches the oil smoke out.

[bigred]

I've just re-read the OP's post and as it seems to only happen when the car's been stood I'll put money on valve guides or over filling of oil.

How many miles you done?

Thanks for all the advice guys, Car has 83,000 on now, it's just been serviced (80k) and the oil is a little high on the dip stick. This lumpy start seems to go away if the temperature rises above 5 - 7 deg. I know most diesels put out some smoke when starting from cold but this just seems to be tied to the lumpy initial start from cold. If it where the valve seals wouldn't there be a belch of blue smoke after over run of the engine?, any way it's booked in to a dealers in a week so hopefully all will be revealed

[Bluefox]

Yes it certainly could, although with the turbo seals you know what has gone as it belches the oil smoke out.

Yeh, of course. Perhaps I should have said "failing"

Still, let us know how it goes

[vos]

You guys need engine pre-heater for cold times.

For example Defa DEFA Warmup has systems for cars.

In Finland almost every car has pre-heater that works electrically or strait from cars own petrol (diesel) system. (Hopefully I explained this well)

Winter times there might be -30 degrees in northern Finland and in southern Finland -10 degrees (normal Finnish winter). So the pre-heater helps cars to start better and it saves engine as well.

[Bluefox]

You guys need engine pre-heater for cold times.

For example Defa DEFA Warmup has systems for cars.

In Finland almost every car has pre-heater that works electrically or strait from cars own petrol (diesel) system. (Hopefully I explained this well)

Winter times there might be -30 degrees in northern Finland and in southern Finland -10 degrees (normal Finnish winter). So the pre-heater helps cars to start better and it saves engine as well.

Lol, it's cold here but not that bad!!

I can see why you guys need pre-heaters.

Mine's been good as gold in the cold snaps we've had recently, and I certainly don't get blue smoke in the mornings so I for one think there's a problem as opposed to coldness.