Skoda Octavia TDI 90 difficulty starting from cold. Especially overnight.

It seems as though the glow plugs are not energising for start. There is no noticable voltage drop when you turn on the key and the glow light comes on on the instrument panel. (In other words the interior light for example doesnt dim as you would expect with the amperage the glow plugs should take). However once started and you drive off, dependant on engine load I can hear a relay occasionally click and the headlights then dip in brightness noticably. This lasts for about a mile.

This indicates to me that the glow plugs are o.k.

If you disconnect the feed to the glow plugs, and turn the ignition on my voltmeter does not give any voltage. Something is happening when you turn on as after a short while you can hear a relay click under the bonnet, possibly coinciding with the glow light going out.

I think basically the question I am asking is when cold what tells the glow plug relay to power the glow plugs.

No faults are shown on the Skoda diagnostic computer and they cannot help without having to have the car in.

They did say that the glow light in actual fact is nothing to do with the cold start. It is basically an engine management light. The cold start system starts when you open the door. Sounds a bit iffy to me.

Has anyone out there had a similar problem and how did you cure it please.

Nothing simiar with my TDI PD100 yet. Although my car drives like a dog for the first couple of miles, and cannot really be pushed more than about 50% until some heat gets in the engine.

Sorry I can't help with your problem, and welcome too, BTW

Hi,

Thanks. Once the car is going it drives very well. No engine problems at all. My concern is that if it ascting the goat at 4 or 5 degrees C then what will it be like at minus that figure.

I remember getting to work during the week long big freeze last winter, and although it drove like a dog as normal, there was little difference in the way it started and held at tickover when it was 5 degrees C, or 10 degrees C below freezing. Was ultra-reliable for me, and I never had any worries at all.

Sounds like glow plugs to me, as if memory serves correct they energise when you unlock/open the door (or something like that).

I have similar symptoms, on various diesels and its always glow plugs...especially when they get around the 3/4/5 yr old mark, and its cold.

glow plug relay is worked from engine ecu (via temp sensor) glow plugs are pre-heated when drivers door is opened. your fault will lye in either glow plugs glow plug relay or temp sensor if you have no voltage at glow plugs when ign turned on then its either relay or temp sensor hope this helps big k.

try disconnecting temp sender and starting as this holds the glow plugs on for the max amout of time. see if it starts easyier. or if u had an amps clamp connect round the main feed it should draw 80amps then fade off. roughly 20amps per pulg. hope this helps

Thanks very much.

If its not a silly question where might I find this sensor, is it on the engine block or in the radiator. Likewise is the relay behind the dash ur under the bonnet

you should find the temp sensor in the cooling pipes to the right of the engine above the gearbox should have 4 wires going to if. relays are in the drivers footwell you have to remove upper trim to gain access.

Thanks for that. I will check it out and get back to you.

Geoff