The Mk3 1.6 TDI hasn't been starting too well on cold mornings over the last couple of weeks. If I cycle the ignition two or three times before cranking the engine starts, but if I attempt to start first time after the glow plug light goes out it's no go. Battery is OK and when starting a warm engine it starts on the button. Suspecting a faulty glow plug I checked them this morning and found all read 0.7 ohms. I then checked the voltage at the lead that plugs onto the glow plugs. All read the same at about 10 volts on switching on dropping to around 2 volts during the time before the glow plug light on the dash goes out.  

Anyone experienced this issue?

Update: This morning the car was all frosted up and started normally on the 1st turn of the key. Just wondering if there is a problem in the wiring. 

A lot of the mk3's have electronic sequenced starting.  If you turn the key and back off as soon as you turn then the computer will start it with its best guess of warming etc. I think if you hold it (like you would on older cars) to get it to turn over it will turn over manually a bypass the computerised sequence.  A bit like having push button start.  You don't have to hold the button down.  I may be related as you seem to have inconsistent starting.

Oh this rings a bell.

 

Might I suggest you check with your local skoda dealer there is no firmware updates for your Octavia.  I read somewhere else (I think it was inrelation to a DSG issue) - that poor starting was sometimes a problem and a firmware update fixed this.  Find a friendly person near you with either a VAGCOM/VDRS/ODBEleven and see what the errors are (if any) and see what the firmware issues are.  If the Glowplugs are going short, the car will flag this.

 

I'll try and find that post....

 

Thanks

 

M

As MarkyG82 said, it sounds like you might be "bypassing" the glowplugs when you are starting (especially as you said electrically they seem OK).

On the Octavia the starting is completely controlled by the ECU, all you have to do is "flick" the key to "Start" and then release it immediately.

If you hold the key in "start" position you bypass the ECU & force it to crank directly without waiting for the glow plugs.

 

when you flick the key & are starting at cold ambient temperatures you should see a message in the Maxidot saying "engine warming" & then "engine Starting" then the starter motor will engage or something like this.

This morning at around 0degC there was a delay of 1-2s before the cranking started on my car.

The delay before cranking will increase as the ambient temperature goes down.

49 minutes ago, Gabbo said:

As MarkyG82 said, it sounds like you might be "bypassing" the glowplugs when you are starting (especially as you said electrically they seem OK).

On the Octavia the starting is completely controlled by the ECU, all you have to do is "flick" the key to "Start" and then release it immediately.

If you hold the key in "start" position you bypass the ECU & force it to crank directly without waiting for the glow plugs.

 

when you flick the key & are starting at cold ambient temperatures you should see a message in the Maxidot saying "engine warming" & then "engine Starting" then the starter motor will engage or something like this.

This morning at around 0degC there was a delay of 1-2s before the cranking started on my car.

The delay before cranking will increase as the ambient temperature goes down.

When I tested the leads to the glow plugs I measured a voltage at the connector inside the cap which pushes onto the glow plug, so I know that glow plugs are getting the voltage when I turn the key to the first position. The Maxidot does not state 'engine warming' at the first key position, when starting it does state 'engine starting' When the problem occurs the engine starting message appears, but the engine doesn't crank and the glow plug symbol on the dash flashes. At the moment it is starting normally.

On 20/01/2020 at 17:35, moley said:

When I tested the leads to the glow plugs I measured a voltage at the connector inside the cap which pushes onto the glow plug, so I know that glow plugs are getting the voltage when I turn the key to the first position. The Maxidot does not state 'engine warming' at the first key position, when starting it does state 'engine starting' When the problem occurs the engine starting message appears, but the engine doesn't crank and the glow plug symbol on the dash flashes. At the moment it is starting normally.

 

sorry for the late reply.

For me, a faulty glow plug would not stop the starter from activating (it will just cause poor start with longer cranking or splutttering combustion during starting).

 

The glow plug flashing is also used to indicate a non-emissions related fault in the engine ECU.

 

I would suspect something more like a brake pedal sensor error or gear lever position problem (you have DSG right?) as these conditions would definately prevent the starter motor from activating.

57 minutes ago, Gabbo said:

 

sorry for the late reply.

For me, a faulty glow plug would not stop the starter from activating (it will just cause poor start with longer cranking or splutttering combustion during starting).

 

The glow plug flashing is also used to indicate a non-emissions related fault in the engine ECU.

 

I would suspect something more like a brake pedal sensor error or gear lever position problem (you have DSG right?) as these conditions would definately prevent the starter motor from activating.

Thanks for the reply.

The problem only occurs when the engine is cold. When the engine is warm it fires up immediately, with no hesitation at all. I tend to cycle the ignition three times and it fires up OK.