Hi all,

I'm a new owner of a Skoda Octavia - purchased it this spring with high km's here in France. Although the records on it were quite clean I continue to have this rather major problem while driving. The first occurrence was following a long drive over 330 kms which I had no problems, but on the return in 6th gear the car started hesitating significantly on the highway. Downshifting seemed to alleviate the problem at the time, and then I immediately filled up the tank as it was below a 1/4 of a tank.  Since then its only been getting worse. It happens typically while revving uphill, in a variety of gears. The trick to this as well is that no warning lights show, nor do any default codes get generated.  The best way to describe it is it feels as though there is water in the diesel. But after several attempts of desiccants to clear the moisture, and a new fuel filter, the problem is still there. Is there any where in the engine that water can leak into? It seems that it must be getting in somewhere to have this continue to be an issue.  Lately as well, I've had the glow plugs start to flash, and the car has gone into security mode 3x, but stops as soon as you stop the car and restart, or sometimes even just slow down. Again, amazingly, no default codes. Can the glow plugs have anything to do with the hesitation? I'm getting them individually checked tomorrow, as well as hoping to have some engine default code show up. But has anyone else had anything like this? The hesitation is terribly frightening - and although it never seems to show much on small short drives around town, it tends to appear after the car has been driven for a bit, and 90% of the time while going uphill - is there any chance that water is somehow leaking in at a certain angle?

It is beyond frustrating, any ideas or suggestions would be most welcome.

 

I sort of had similar hesitation a few times when I let the tank drop to a low level, as I'd normally never let it drop below half. But after letting it drop until the light came on a few times it went away as presumably it had cleared out all the rubbish at the bottom of my tank.

Firstly, glow plugs are only used to perform cold starts (and not even then if the air temperature is above 5C on these engines). So your issue can not be glow plugs.

 

It does sound a bit like water or air getting into the system.

When the glow plug warning light flashes - its after a knocking lurch while driving - not quite the same feeling as the hesitation - any idea why this is happening? The glow plug light then starts flashing, and car sometimes goes into security drive mode.  But the symptoms are just similar enough, but not understanding why its igniting the glow plug warning?

 

I will also try dropping the gas tank lower - I've only done it once so far. The hesitation doesn't seemed to be linked to the amount of gas in the tank - it happens at all levels - wondering if the tank itself would benefit from a complete drain?

The glow plug warning light doubles as an engine management light on these. The fault won't be anything to do with the glowplugs themselves. If this light is coming on whilst driving I would be very surprised if they're aren't any fault codes stored. What code reader is being used?

 

It may be the turbo vanes sticking if the loss of power occurs when going uphill - ie when the engine is under greatest load. Another possibility is the MAF sensor, but really you need to get the fault codes read properly before making any assumptions, otherwise its just guesswork.

 

It does sound a bit like water or air getting into the system.

 or maybe a vac in the tank   not done my homework but 4x4 tanks are different to all the others    think there's a hump in the middle for the prop shaft and two feeds   do some digging on that front

I've had a flashing glow plug light a couple of times, once was as a result of an EGR fault, the other was MAF/MAP related, if I gets chance tomorrow I will post the fault scans from these. Both of these could account for the issues you are experiencing. EGR fault was a one off so far but my EGR does seem to cause a lot of hesitation so is probably a bit gummed up (A job I need to get around to at some point), the other was a broken wire on the MAP sensor - wire emerges from under the battery and travels across the front of the engine where it is scotch locked into another part of the wiring loom.

Anyway this is all speculation without a fault scan.

HTH

Checked it with mechanic today, still no fault codes. And Glow plugs are firing fine. Off to try someone else who he's recommended that has more experience with mystery afflictions.  Thanks for the advice, if any else has anymore ideas would appreciate it!

These are the 2 faults that caused my glow plug light to come on/flash:

 

Address 01: Engine        Labels: 03G-906-021-BMM.clb
   Part No SW: 03G 906 021 SS    HW: 03G 906 021 AB
   Component: R4 2,0L EDC G000SG  1302 
   Revision: --H08---    Serial number: SKZ7Z0H4763111
   Coding: 0000172
   Shop #: WSC 73430 000 00000
   VCID: 820F4DABDD7E6108B6F

1 Fault Found:
000568 - Manifold Pressure / Boost Sensor (G31)
               P0238 - 000 - Signal too High - MIL ON
             Freeze Frame:
                    Fault Status: 11100000
                    Fault Priority: 1
                    Fault Frequency: 1
                    Time Indication: 0

             Freeze Frame:
                    RPM: 0 /min
                    Speed: 0.0 km/h
                    Load: 0.0 %
                    Voltage: 12.01 V
                    Bin. Bits: 00101100
                    Absolute Pres.: 183.6 mbar
                    Absolute Pres.: 2182.8 mbar

Readiness: 0 0 0 0 0

 

and:

 

Address 01: Engine        Labels: 03G-906-021-BMM.clb
   Part No SW: 03G 906 021 SS    HW: 03G 906 021 AB
   Component: R4 2,0L EDC G000SG  1302 
   Revision: --H08---    Serial number: SKZ7Z0H4763111
   Coding: 0000172
   Shop #: WSC 73430 000 00000
   VCID: 820F4DABDD7E6108B78

1 Fault Found:
001025 - EGR System
               P0401 - 000 - Insufficient Flow - Intermittent
             Freeze Frame:
                    Fault Status: 00110000
                    Fault Priority: 1
                    Fault Frequency: 2
                    Mileage: 150393 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 19:12:09

             Freeze Frame:
                    RPM: 1785 /min
                    Speed: 93.0 km/h
                    Load: 0.0 %
                    Duty Cycle: 17.4 %
                    Duty Cycle: 95.1 %
                    Mass Air / Rev.: 270.0 mg/str
                    Mass Air / Rev.: 460.0 mg/str

Readiness: 0 0 0 0 0

I would get the egr  cleaned and checked first  it sounds like it's not closing properly when you need some power   then worry about the other if it comes back as a fault

Ok, latest and greatest. Most recent mechanic ruled out the EGR - disconnected I think and that didn't solve the problem. Thinks instead I need a new turbo system. Is it possible to clean the vanes, or is it a bit of a lost cause and I need the turbo replaced?

disconnecting does not "solve the problem"  it assumes the valve is tight closed at rest which may not be the case-----looking at the pressure figures it may well turn out to be sticky vanes as they should be "open" at rest and then start to "close"  (swap those terms if you like)   as the revs rise   this controls the pressure from going too high   unless there is another reason to believe there's a problem I would always go for a Proper strip and clean and an inspect of the egr cooling system---then you have a better idea of your turbo condition if some thing is found damage/wear  then it's anew or recon job  best of luck