Advice appreciated please !

I have a 2011 reg Superb 2.0 CDI CR DSG which has a mysterious intermittent cold starting problem. The car has a full service history and has 70,000 miles on the clock.

The car always starts first time when it is even slightly warm.

However when the engine is cold, often the first time of starting each day, it may sometimes start OK, but frequently will not start at all. This failure to start when cold can be overcome by spraying Bradex Easy Start into the air intake.

The Skoda Dealer says they cannot identify any fault codes on their diagnostic erquipment and they have been unable to cure the problem.

 

The fact that Easy Start always seems to make it go, has me thinking that the issue is something to do with fuel supply rather than an immobiliser problem. I have read about defects on a MAF sensor (but have not yet removed mine for examination). However, if a problem can arise because the sensor wire is dirty, I do not understand how that could be an intermittently-occurring problem. Could it be as simple as a loose wire ??

 

Any knowlegeable pointers on this will be deeply appreciated.

 

Thank-you

What about battery?

If there are no fault codes, then I would check that the the air intake tube/duct after the MAF is still airtight.

 

If air is getting in through a leak/seal/crack in the plastic, then the car is trying to start using values measured by the MAF that are nonsense as the air to fuel ratio and temperature is being altered post MAF measurements. The Easy Start Spray is helping to balance that out...?

 

When I had this issue (on a BMW) it was also intermittent - the leak I found could "seal itself" if the plastic duct expanded due to engine heat or a warmer day. There were no "fault codes" as all the sensors were actually working properly, it was just a case of unmeasured air getting in after the MAF.

Had a Renault years ago that wouldn't start when cold, and got worse.  you say it starts ok with easy start

Now with not working on trucks/cars for a very long time so out of touch with things and how they work.

Have you tried leaving the ignition on for a while before trying to start as that's what I found out with the Renault. Non starting to leave ignition on then it would fire 1st time 

Just a thought ???

 

 

 

When a diesel is having cold start problems, the first place to look is the glow plug system. Have you had this checked over? Also, does the problem get worse with very cold weather (or better in warm weather)?

As has already been mentioned, do not underestimate the battery. A failing battery on the Superb can result in some very unusual faults, poor cold and/or hot starting being one of them.

 

Don't engines become reliant on Easy Start eventually?

Many thanks to all for these very interesting ideas. I went on a short trip after first posting this topic, but I'll now be working to try to follow up on these things, thanks again.

The car has been running with the starting problem for over a year:- it's actually my daughter's and I've just recently taken it into custody and begun to use the Easy Start spray. The engine turns over quickly and easily on those times it doesn't fire, so I imagine a defective battery might have showed itself in other ways by now, though I will of course have it checked.

After not being used at all for 5 days, Easy-Start was required to make it go this afternoon. Then after just 3 minutes idling, i.e. without much appreciable warming, the car was switched off and immediately re-started first time.

My search will continue........

Thanks 

Like suggested before, the first thing to check would be glow-plugs.

 

They're not that expensive and don't exactly last forever, yet they're essential to getting a diesel engine going. If it starts with a warm engine with no issue, that immediately points to that.