My car sometimes takes 2 or 3 tries to start - when hot

[viralchristian]

Hi All,

 

   I have got an Octavia MK3 - 15 plate diesel automatic. It has done about 31K miles and has been fully serviced by dealer for last 3 years.

 

   For last 6 months I have got an odd issue where my Start/Stop system will not start the car back when I lift my foot from the brake.

   When I lift my foot from the brake - it will try to start the engine and the engine will crank but will then stop after 1 or 2 seconds.

 

   Now gradually the issue has started to happen when I am parked and try to start the engine after few minutes.

 

   It used to always start after the second try but now gradually I have to try for a 3rd or even 4th try sometimes.

 

   The engine will crank and car will try to start but it feels as if computer should have continued for another second more to make the engine start.

 

   After my second try - I usually turn off the power to everything and then try again after 10 seconds - and suddenly it works !

 

 

  This does not happen every time - I would say it used to happen once in a month - and now gradually it is happening once a week.

 

 

 

   Any ideas ?

 

Thanks !

 

[viralchristian]

I initially thought it must be the battery - as we had a bad winter this year in UK.

I went to Halfords today to get the battery tested but the battery is fine.

 

 

I now think it could be the injectors clogged up - so just bought some RedX Diesel - £2 for 250ml - half price TESCO

 

Will pour it in the tank and see if the issue goes away or improves.

 

 

[Gaz]

Best to have it plugged in to diagnostics to see if it throws up any errors.  It could be something obvious and you might otherwise be on a wild goose chase.

 

Gaz

[Octy0GG]

I'm assuming it is always fine from cold.

 

Some possible culprits:

Fuel Supply / Fuel filter / Return valves in fuel supply.

 

Do you know if the filter has ever been replaced?

Any possibility of lines being connected up wrongly?

If it is like Octavia 2 these sort of faults will not show up directly on a scan.

 

[MarkyG82]

This is very similar to a somewhat documented issue with some older PD engines. My old car had it for a number of years. The only thing that cured it in the end was a remap. It was something to do with properties in the map requiring the cranking speed of the starter to be above a certain value when the oil (or something) temp was up or the fuel pump wouldn't go.

[SuperbTWM]

54 minutes ago, MarkyG82 said:

This is very similar to a somewhat documented issue with some older PD engines. My old car had it for a number of years. The only thing that cured it in the end was a remap. It was something to do with properties in the map requiring the cranking speed of the starter to be above a certain value when the oil (or something) temp was up or the fuel pump wouldn't go.

 

As I understand it, the underlying issue was the poor starter, the remap was just a way round it. Put a new starter on my golf and after 4 years it finally started well on a warm start.

 

Could be a very similar thing happening, unplugging the CTS would probably prove it as it usually defaults to a low value I think when unplugged 

 

 

[shyVRS245]

Assuming the guys at Halfords tightened the battery terminals because if they work loose (lots of speed humps about where I live) this can affect the stop/start as we found out on wife's 2015 Rapid Spaceback. This is a cheap fix if you want to check!

[viralchristian]

Thanks everyone for the suggestions - I still haven't managed to run the diagnostics and look for fault codes using VCDS - I might do it this weekend.

 

Putting 2 shots of Redex diesel in a full tank seems to have worked - I understand its too soon to be sure that its completely fixed, but I can feel that the car now vibrates lot less when cold / hot starting.

 

I can feel that the effort needed to start the engine is lot less compared to what it was before using Redex.So, maybe it was some impure fuel or too many short journeys - clogging the injectors !

 

 

I will still keep an eye on it and post any updates here.

 

 

 

 

 

 

On 08/08/2018 at 17:14, Octy0GG said:

Do you know if the filter has ever been replaced?

Any possibility of lines being connected up wrongly?

 

It has been serviced 3 times by a Skoda dealer so I think they must have done their job correctly.          

Yes, I doubted Fuel / Air intake filter might be the issue.

 

Let's see, if the issue still happens then I might try and get it checked by a garage.

 

 

 

[paulsoava]

Did you get any fault codes? Does it also shudder when that happens? On my Octavia II diesel this was a symptom of a worn out DMF: once in a while it would fail restarting when the engine was warm and would send a loud bang and a shudder to the cabin. Another sign of that was a sort of grinding sound when idling in neutral.

[ChoonDoode]

One important question to ask, is what diesel are you using?

 

A lot of people do say Shell V Power gives you the placebo effect, but even normal Shell is better than any supermarket fuel.

 

The other question is have you done a good ol' Italiian tune up? Works wonders.

[viralchristian]

Update (not much changed)

 

I still have this odd issue sometimes but it always starts after 2 or 4 tries.

 

I have checked with VCDS but no fault codes logged.

 

I have shown it to an independent garage but they could not reproduce the issue or see any fault codes.

 

Googling the issue - I can see a lot of people having similar issue - but no specific fix is suggested.

 

For now I will not worry much - just disabled the Start/Stop (as it twice gave me issue with not starting up at green lights)

 

 

[silver1011]

My money is on the starter motor.

 

I appreciate we're talking MkIII here but almost every single warm / hot starting issue on the MkII Octavia was eventually tracked down to a faulty starter motor.

 

Modern cars are very good at hiding the obvious sometimes.

 

This thread goes back to August. When in 2015 was your car registered? If at the time it wasn't still under warranty it can't have long expired?

 

Full main dealer service history and low mileage would likely have got you some goodwill if only just out of warranty.

 

Edited 6 December, 2018 by silver1011

[ian_feel_keepin_it_reel]

I've seen similar symptoms on my old 1.4tdi polo. It was the crankshaft position sensor faulting out when it heated up. 

 

That threw a fault code though. 

[MarkyG82]

3 hours ago, silver1011 said:

My money is on the starter motor.

 

I appreciate we're talking MkIII here but almost every single warm / hot starting issue on the MkII Octavia was eventually tracked down to a faulty starter motor.

 

 

Same.  As above I have many things changed before finally 'finding' a fix which was a remap.  To be fair I didn't try a new starter but when I found that it was fixed I put it down to the map having different requirements for starting conditions.

[Raffaz]

Darkside developments mention this on their site, maybe worth speaking to them

 

https://www.darksidedevelopments.co.uk/ecu-tuning/

[viralchristian]

I know this is a very old thread - but I think I have managed to get my issue sorted - so posting it here.

 

As I mentioned I was having issue with car not starting on first try.

This went on and on for last 1 year and it got worse. So bad that it would take sometimes 6 or 7 tires to start the car.

(Most of the times the car would start on the first try though)

 

Fix:

2 weeks back on a frosty morning - the car battery just gave up.

It would not turn the starter motor and all the dash lights would start flashing.

Called AA and he replaced the battery with a new one.

 

Since getting a new battery - 

I can feel that the car start is more powerful compared to before -

and the intermittent issue I was facing is gone.

 

 

Conclusion:

 

My issue was caused by a weak battery - replacing it fixed the problem completely.

 

 

 

[MarkyG82]

3 hours ago, viralchristian said:

 

My issue was caused by a weak battery - replacing it fixed the problem completely.

 

 

 

Glad you found a fix. Could you keep an eye on it though. My suspicion is you have masked the problem. No doubt the battery needed replacing but you may find it will return in 2-3 years. Following the remap my mk2 was perfect even when the original battery got to over 10 years old and struggled to get the electronic bits going.

[flybynite]

21 hours ago, MarkyG82 said:

Following the remap my mk2 was perfect even when the original battery got to over 10 years old and struggled to get the electronic bits going.

 

The original battery wouldn't start my petrol after 3 years, not a chance on a diesel. They fitted better batteries to MK2s. You NEED a good battery to start a diesel

 

The Vartas I use still crank diesels after 10 years, the Moll EFB wouldn't crank my petrol after 3

 

I stand by what I said HERE

 

Especially when the engine is hot and the outside is cold, it needs to think, thinking takes battery.

[Lingnoi]

On 16/12/2019 at 14:11, viralchristian said:

My issue was caused by a weak battery - replacing it fixed the problem completely.

 

 

 

 

Ditto. My 1.4TSi Octy Elegance on a 63 plate was doing exactly this with Stop-Start. New Varta AGM battery has cured it completely, hasn't happened again since, so I assume my original OEM battery (which was coming up for 6 years old) was due to be replaced.

Edited 20 December, 2019 by Lingnoi
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