Intermittent Starting Problem

[gibby]

Hi all. I have a 2010 Diesel Roomster with 110,000 on the clock.
It's been good as gold for 10 years but has decided to fail today.

It started fine this morning. I stopped somewhere to make a call and the lights all came on, everything working except it won't start.
This has happened 3 times since and the garage can't find a fault and it started first time for them.

The engine is not cranking and there is no ticking from the starter motor.
The battery is just over 2 years old. The starter motor was replaced less than 6 months ago.
The garage state its not the alternator and the battery is fine, although I have noticed for the last few weeks it sounds sluggish in the morning unless it has had a good run the day before.

I can bump start it very easily.

Has anyone any ideas on what this can be?

Thanks,
G

[loony]

I think you best bet is to try another battery. although they are saying its fine it needs to be ruled out. Volts and Amps load test.

 

I was getting strange things happen like the trip resetting and electric windows hunting for position although it would start ok.

 

And then My battery died recently, i could leave the car for a couple of days and then it would be flat. we tested to see if anything was drawing power and it wasnt so fitted a new battery from

my local trusted group and havent had a problem since. now have left it for a couple of weeks and no problem.

Edited 25 January, 2021 by loony

[26DIPP]

If it was the battery it should start straight away when jump started or after a good charge for the current battery. Also you should not have a start / no-start situation with the current one. Have you or have they checked the keyfobs to check whether the immobilizer interferes as it does not pick up the transmitter properly? One of my daughter's keys - a replacement - seems to have a weaker signal  and sometimes there is nothing and on next turn it starts.

Has the garage checked both parts of the circuit, i.e. 12v supply and earth points if there was work done on the starter recently?

[SilverRoomster]

Same problem as OP - 2010 Skoda Roomster Diesel SE with 100,000 on the clock.   Starts fine most of the time but lately been doing it more and more not wanting to start, but eventually does.  The fuel pump clicks before starting so don't think it's that. Charge the battery up every week (reads 12.3 idle and 11.9 when starting up) although battery around 7 years old.  Yesterday it just wouldn't start at all - even jump starting it took a couple of minutes to fire into life.   It seems to be just not wanting to fire up but when started it needed to be revved up for a bit to "catch".    Once going it was fine and subsequent tries when I got home started no problem!   After reading much on this forum the fuses have been checked, etc and the one thing I have read is about the battery needing to be in tiptop condition for starting!  Can you let me know your thoughts?

Also the driver and back seat electronic windows are the only ones that work - the passenger side and back seat windows are completely dead.  Anyone have any clues on this one.  Thanks, 

[PipH]

When you say 11.9 volts starting up, is that the voltage after you switch on the ignition ?

If so, then the battery is on the way out or could just be low on charge if you do lots of short journeys.

Perhaps try giving the battery an overnight charge.

 

But being as the battery is 7 years old & it is summer when there is much less strain on the battery, I think a new battery is probably the way to go.

[SilverRoomster]

Yea it was reading 11.9 when switching on the ignition - read it online as a means of testing the battery.  I bought a new battery yesterday as after reading on here that for some reason Skodas need loads of juice when starting.   I've actually just been out and it started no problem.   Lately it has been lots of shorter journeys the car has been doing and although the battery has been put on charge several times it was getting to the point where I was losing confidence in the car.  So I hope the new battery solves the problem - I will report back after 2-3 weeks and let you know how it goes!

However the window problem still exists and for some reason the back passenger window has stopped working again, the only window that works is the drivers - oh well at least it's starting!!! 

[PipH]

Regarding the windows, have you checked the cabling in the rubber bellows of the drivers door, where the cables run from the car interior to the door near the hinges.

 

They have a habit of fracturing inside the plastic cable covering & sometimes even break, due to the bending every time the door is opened.

 

Worth pulling back the gaiter & checking.

[bobspark]

What I found that helped me monitor the cars voltage was a cup holder cig socket/ USB doubler which has an led display which toggles between USB and car voltage.

When the 1.9 diesel heater plugs energised on start up the voltage really drops to about 10.1volt ,and it also showed the relay stayed in  some seconds after the heater light went out.

You need  at least 12 volt to start comfortably.

I did check the heater plugs resistance all was normal.

So in winter I wait till  I can see 12.1 on the display I know I can start without problems.

[SilverRoomster]

Thanks for your comments / suggestions - will certainly give it a try and report back here to help others.

[SilverRoomster]

Just to let you know the windows are now working - took PipH advice and checked the wiring inside the door gaitor.   4 wires broken so fixed and lengthened.    However 2 of the switches are not working and need to be replaced but at least all 4 windows open and shut from the drivers controls.

 

as for the starting problem, still at it.     The glow plugs all needed replaced but the lead connecting  them isn't working so replacing the relay (I've started another post regarding this).   

[SilverRoomster]

New relay fitted this morning and glow plugs now working - we've had intermittent starting problems (added my comments to an existing post re this) - new battery fitted, new glow plugs and replaced faulty relay.   Hoping that this works but will report back in a few weeks time to update.   It may help others in the same situation.

[SilverRoomster]

I'm afraid after all this time we seem to be having the same problem.   We left the Roomster sitting for a few weeks and didn't use it - when eventually we did use it again,  it fired into life every single time for about 2 weeks.   Then it started its nonsense again.   Believe it or not when we thumped the top of the dashboard the damned thing burst into life when turning the key.   It starts no problem in the mornings but after a run that's when we have difficulty starting it again.   It's intermittent and doesn't do this every time the car is used but still can't get to the bottom of it!

[HeavyMetalRich]

On 15/10/2021 at 23:44, SilverRoomster said:

I'm afraid after all this time we seem to be having the same problem.   We left the Roomster sitting for a few weeks and didn't use it - when eventually we did use it again,  it fired into life every single time for about 2 weeks.   Then it started its nonsense again.   Believe it or not when we thumped the top of the dashboard the damned thing burst into life when turning the key.   It starts no problem in the mornings but after a run that's when we have difficulty starting it again.   It's intermittent and doesn't do this every time the car is used but still can't get to the bottom of it!

 

So when you turn the key to try to start, does the engine turn over or does it not do anything?

 

If it does nothing, one thing you could try is wiggling the key while its turned into the start position. If you then get action, you probably need to replace your ignition switch. If that does nothing, it might be worth checking the earth leads from the engine for damage and/or corrosion.

 

If your engine does turn over but takes a long time to fire, you might have a fuelling issue.

 

[Nepomuk]

Found this thread at the weekend when looking for a cure for a problem on my Octy II with DSG. Everything electrical worked with the ignition on, but it wouldn't start. I got a few spurious messages on the dash display, including "select P or N" (it was already in 'P'). 

 

Used jump leads from my wife's car (Octy III) and it fired up straight away. Fifty miles later and everything is fine.

 

I've reached the conclusion that the nearly 10 years old battery needs mending with a new one.

 

 

[SilverRoomster]

Yea it turns over and I think we have also come to the conclusion it's a fuel issue too (but what?).    I've read on here that it could be so many things.    When it does start there are no issues with driving it (short or long journeys).  I would take it to a local garage but if it starts then nothing would show on the computer read out.   Any suggestions gratefully accepted!!!!

Edited 4 November, 2021 by SilverRoomster
Addition

[HeavyMetalRich]

12 hours ago, SilverRoomster said:

Yea it turns over and I think we have also come to the conclusion it's a fuel issue too (but what?).    I've read on here that it could be so many things.    When it does start there are no issues with driving it (short or long journeys).  I would take it to a local garage but if it starts then nothing would show on the computer read out.   Any suggestions gratefully accepted!!!!

 

Ok then, well the first thing you could try would be turn the ignition on and listen for the fuel pump priming. It should run for a few seconds so you should hear it if it's working.

 

If you know that's working, you could then try priming it a few times (turn the ignition on for about ten seconds and off again) to make sure the fuel has plenty of pressure in the low pressure system.

 

It could be fuel running back to the tank and trying to prime up might well show if the pump is faulty. If this becomes apparent, a check of wiring to the pump would be worthwhile before testing the pump and replacing if necessary. 

 

Let us know how you get on.

[SilverRoomster]

Not been using our Skoda much these last months but have noticed on the odd occasion that we have trouble starting it turning the ignition on as HeavyMetalRich suggests does seem to work.   So at least that particular problem may have been overcome - for now.   Thanks for your advice HMR 👍🏻.

[SilverRoomster]

Our Skoda Roomster still having issues starting - sometimes!!!!    Always starts first thing but at times difficulty getting it started again when used for either long or short journeys.   What we have noticed is when it has difficulty starting it will drive fine for about a mile then cuts out - quite dangerous!!!   Leave for a minute or two then fires back into life, although to start with the rev counter goes quite high after it catches.  Been twice on diagnostics and nothing showing.  Anyone having these problems?  Time for another car I think.

[26DIPP]

Have you ever done any diagnostics, have they checked the ECU?

Edited 16 April, 2023 by 26DIPP

[SilverRoomster]

Thought I would repost this problem about difficulties on starting Roomster.   been on diagnostics twice - no problems found!!!     Starts no problems from cold but when engine warm/hot it has difficulty starting.but will eventually start.  However when driving after the difficult start it will cut out - once stopped it will start again and then drives no problem.    Any ideas anyone?.  

Edited 24 June, 2023 by SilverRoomster

[HeavyMetalRich]

Hello again, sorry to read that you're still having issues.

 

It reads like whatever is at the root of the problem is active when the engine has warmed up.

 

Do you get the glow plug light flashing or anything like that when it happens.

 

I would be suspecting wiring myself, either the injector loom which can be broken or wiring to the crank sensor which can chafe through or get stretched/broken on the engine block I think. A VW specialist should be aware of these problems enough to investigate, they were common enough on all of the diesel engines of the time.

[SilverRoomster]

Many thanks for getting back to me HMR -   No glow plug flashing, just takes ages, when the engine is hot/warm to start and then whilst driving cuts out - obviously very dangerous.    However when it does cut out it starts and drives again no problem.  It also starts from cold first time.

I'll have a wee look at that wiring you spoke about and see how I get on. Thanks for your help.  

[HeavyMetalRich]

Thinking about it now after your latest description, I had a bus that did the very same and it turned out to be the fuel pressure regulator on the end of the fuel rail had gone faulty. 

 

Another thing to check could be if you're "throttle body" and inlet manifold is all choked up with carbon deposits. A sticky throttle valve could cause your cutting out but I would think you'd have other running issues with that too.

 

Anyway just a few more ideas to try.

[SilverRoomster]

Just to let everyone know in the same position I was in - it turned out to be the camshaft sensor needed replacing (£30).  Had it on a small diagnostic device and this time it showed up as a problem with camshaft.  The altanetor also needed replacing, but dont think this was contributing to the starting problem, was probably more to do with the fact that the car hadn't been used for months due to the starting/cutting out problems. 

So far, so good, been using the car again for a couple of weeks and no problems starting.  Hopefully thats the problem fixed.