Difficult starting when engine warm - what solution is the best?

[DinoDem]

Hello dear forum,

 

My octavia has the known issue with being quite difficult to start (the starter cranks for several seconds) when the engine is warm/hot. When the engine is cold, there is no problems at all.

 

Now I have had few suggestions on what to do from different sources, but I would really like to hear your opinion:

 

1. some suggest to install a new starter (which I would prefer, since it is not preforming according to the specs)

 

2. others suggests to get an engine software upgrade (since it expects the starter to reach a certain rpm, but it eventually never comes due to a "broken" starter). This option is here more costly than number 1, and I sill have a "broken" starter, but it might remove the problem (evt. temporaly).

 

3. som suggests that a new battery may help on this: then I dont know why there is no change on this when the engine is cold?

 

Please let me know wht you think I should do!?

 

All the best.

[IngusSeflers]

What engine we talking about???

[xman]

Check the temperature coolant sensor with vcds.

 

http://www.darksidedevelopments.co.uk/products/vw-1-9-2-0-tdi-2-pin-grey-coolant-temperature-sensor-06a-919-501-a.html

Edited 20 February, 2015 by xman

[Mikek3111]

I had a similar issue yesterday. Stuck down in London where car wouldn't start. Checked with OBD2 reader and had engine coolant temp sensor intermittant fault. Changed the sensor this afternoon all seems ok atm. Sensor cost £7 took all of 3mins to fit

[Anddenton]

When warm engine must meet minimum rpm on starter before fuel is injected. When cold fuel is injected regardless, hence poor warm starting can indicate a week battery or maybe week starter motor.

[flying pig]

When warm engine must meet minimum rpm on starter before fuel is injected. When cold fuel is injected regardless, hence poor warm starting can indicate a week battery or maybe week starter motor.

+1

I too have an Octavia Elegance 1.9PD Mk 2 which would start fine when cold, however when it was warm it would briefly fire and then stop with a hell of a rumble. I changed the battery and all has been fine since.

By all accounts, when the engine is warm it requires a higher cranking speed which a tired battery is unable to provide.

I notice that yours is a 2005 model. Is it still on its original battery? If so, I'd recommend you change it before you do anything else.

Hope this helps.

Edited 21 February, 2015 by flying pig

[mk2cliffy]

I've got exactly the same problem on a 2005 plate 2.0tdi. Heard a few different remedies but which do you try first, battery? Starter motor? Coolant temp sensor?

[Mikek3111]

I've got exactly the same problem on a 2005 plate 2.0tdi. Heard a few different remedies but which do you try first, battery? Starter motor? Coolant temp sensor?

Start with the cheapest imo

[mk2cliffy]

Is the coolant sensor easy enough to replace? I've heard people saying about the cam shaft sensor as well?

[Mikek3111]

I changed mine yesterday in about 3 mins. New sensor and flat blade screwdriver is all that's needed.

[kevvo]

I went through this with my now ex 2005 1.9 TDI Octavia. I changed Battery, Coolant sensor to no avail. Went to shark Performance for a turbo issue and while there they did the Software update which cured the problem.

[Dakota558]

I have the same problem with my 2007 1,9 TDi. I went to a guy today to change some settings in VCDS, and at the same time I checked the error codes. There was one for the camshaft sensor (G40). I wrote down the error code, but I managed to loos that piece of paper. Other than that, there was no error codes present. Could the camshaft sensor have something to do with this issue?  

[IngusSeflers]

I have the same problem with my 2007 1,9 TDi. I went to a guy today to change some settings in VCDS, and at the same time I checked the error codes. There was one for the camshaft sensor (G40). I wrote down the error code, but I managed to loos that piece of paper. Other than that, there was no error codes present. Could the camshaft sensor have something to do with this issue?  

:yes:

[flat-eric]

My pd vrs estate had the same problem, new battery fixed it!

[mannyo]

I have the same problem with my 2007 1,9 TDi. I went to a guy today to change some settings in VCDS, and at the same time I checked the error codes. There was one for the camshaft sensor (G40). I wrote down the error code, but I managed to loos that piece of paper. Other than that, there was no error codes present. Could the camshaft sensor have something to do with this issue?  

 

Yes, I had warm start issues with my old PD140 Superb MK2. VCDS reported a cam sensor fault, so I replaced it and the car started fine cold or warm afterwards.

[Dakota558]

Ok, thanks! Is it a DIY-job to replace it?

[Dakota558]

And does anyone have the part number for the sensor?

[silver1011]

I had warm and hot start issues on my 2008 PD140.

 

Another vote for the battery here.

 

100% cured.

[VrsMule]

Cam Shaft Sensor, Wifes A3 1.9 Tdi was the same, grand when cold, stuttery when hot. New battery did nowt had the same G40 code, replaced the sensor and it's been fine since.

[mannyo]

Ok, thanks! Is it a DIY-job to replace it?

 

Easy DIY, just difficult to get at.

 

Remove upper cambelt cover and you'll see it in the cylinder head in the top right.

[Dakota558]

Ok, I found this video showing the removal of the sensor.

 

https://www.youtube.com/watch?v=r4GzRBmhMO0

 

It looks doable, but I fear I'm gonna drop the bolt holding the sensor in place...

 

I believe I found the sensor here (Norwegian site): http://www.skruvat.no/Sensor-kamakselposisjon-P376538.aspx

 

It lists the following part numbers:

 

03G 957 147 B

03G 957 147

045 957 147 D

076 906 433

 

Can someone confirm if this is the correct one?

[Dakota558]

I managed to install the new sensor. According to the video it's a 10 minute job, it took me 2 hours... Mostly because it's very hard to see what you are doing. So far I haven't been able to check with VCDS to see if the code is still present, but the car is much easier to start when warm so I'm gonna call this a success so far.

[flying pig]

Mate. I've previously mentioned changing the battery and I'll mention it again. Try changing your battery and see how you get on. You might be surprised!

[Jamesyboy]

I have the warm starting problem. My battery is less than 3 years old, but I had it tested at a specialist which tested the CCA. The battery is fine. My mechanic also says the starter sounds ok. No fault codes anywhere. Had the fuel filter changed but no improvement. Any suggestions?

[silver1011]

The battery, honest!