Recently replaced our W reg Octavia 1.8 Turbo SLX with a W reg Octavia 1.9 TD with just 28000 miles on the clock. The car always starts with the first turn of the engine when engine cold but needs several turns when hot and then starts with quite a bang, whiz and clutter before the engine quickly settles down. This is so unlike my Renault Laguna 1.9TDI which always starts instantly on the turn of the ignition, whether engine hot or cold. Is this a characteristic of the Mrk. 1 Octavia and we have to learn to live with it or is there a technical problem ?

Grateful for any advise

Moved

Very unlike mine anyway. Starts the same, hot, cold, or even warm!

could this be a double whammy of failing battery and knackered coolant temp sensor?

Mine is very difficult to start when hot. Takes a lot of cranking to get going. Id be interested to see what people can come up with. I've had a new battery but that was for different issues. Sorted that but not the hot start.

Possibly heat soak into the starter motor. Does the starter spin slower when the engine is hot?

Warm/hot start issues can be caused by a sticky anti-shudder valve. However that generally does not cause a bang, just means you have to hang on the key for a few more seconds than when cold.... Also add in a possibly faulty coolant temperature sensor.

The second issue can be checked with the vag-com, the first is more manual (open bonnet & check!)

Warm/hot start issues can be caused by a sticky anti-shudder valve. However that generally does not cause a bang, just means you have to hang on the key for a few more seconds than when cold.... Also add in a possibly faulty coolant temperature sensor.

The second issue can be checked with the vag-com, the first is more manual (open bonnet & check!)

Many thanks for your advice. The coolant temp. sensor seems a possible cause of the problem but before I take it to the garage to be checked, could you explain what the 'anti-shudder valve' is, where is it and how does one check it is working okay. Really grateful for your time.

Possibly heat soak into the starter motor. Does the starter spin slower when the engine is hot?

Not heard that one before ! Are you saying the starter motor 'sucks up' heat from the hot engine and makes it less efficient ? To my non mechanical mind, machines work better hot than cold. As far as your last point is concerned I will check over the next couple of days (when frozen Dover thaws out a bit !) but I have a feeling the starter may be slower when engine hot. Many thanks for your help.

My money is on the battery. Take a look at the following thread.

http://briskoda.net/forums/topic/139926-tdi-hot-starting-problem/

Many thanks to you all for your valued advice. Following the link in rwbaldwin's reply it is reassuring to learn that this is a common fault with the Octavia TDs (just the Mk 1 ?) and I am not out in the cold. I think I will try replacing the battery first and if that doesn't fix it I'll look at the coolant, temperature sensor, the fuel sensor, the glow plugs and the anti shudder valve (whatever that is !) in that order. The 'bang' I mentioned in my original listing is more of a loud knocking/vibrating sound which I guess could be due to loose exhaust fittings.

I will let you know how I get on

Not heard that one before ! Are you saying the starter motor 'sucks up' heat from the hot engine and makes it less efficient ? To my non mechanical mind, machines work better hot than cold. As far as your last point is concerned I will check over the next couple of days (when frozen Dover thaws out a bit !) but I have a feeling the starter may be slower when engine hot. Many thanks for your help.

Sorry, that was a suggestion for Andy's problem not yours.

However, I am saying, not suggesting, that electric motors work better when they are cold (lower resistance, so more current is used in spinning the armature rather than generating more heat...)