HELP ! 9N misfiring and juddering and lambda sensor on !

willow5 · Post by **willow5** » Thu Mar 06, 2008 7:43 pm

Good evening,

My polo has suddenly developed a fault - it's a 1.2 2002 polo 9n which is now misfiring and very difficult to drive !

The lambda sensor light has also come on.

Looking at previous posts on this forum, I understand the fault could be the engine coils but could also be the catalytic converter ?

Any help appreciated

Many Thanks

Chris

willow5 · Post by **willow5** » Thu Mar 06, 2008 8:06 pm

OK, just done a VAG-COM test and this is what it has come up with:

3 Faults Found:

16502 - Engine Coolant Temp. Sensor (G62): Signal too High

P0118 - 35-10 - - - Intermittent

16556 - Fuel Trim: System Too Rich: Bank 1

P0172 - 35-10 - - - Intermittent

16686 - Cylinder 2 Misfire Detected

P0302 - 35-10 - - - Intermittent

Please can someone decode these for me ?

Thanks

Chris

AKs_SlickPolo · Post by **AKs_SlickPolo** » Thu Mar 06, 2008 8:31 pm

To decypher that it seems its saying that your 2nd cylinder coilpacks faulty and your coolant temp sensor. Both common issues esp on earlier models.

It may be that the fuel system one is related to a faulty lambda probe but probably worth replacing the other two cheaper stuff first.

If the lambda's gone you'll find it consumes more fuel than normal.

willow5 · Post by **willow5** » Thu Mar 06, 2008 8:41 pm

Excellent, many thanks AKs_SlickPolo

Is this an easy DIY fix ? Is the coil pack located over the spark plugs ? And while I am changing the 2nd coil pack, is it worth changing the other two at the same time ?

Also, please can you indicate where the coolant temperature sensor might be located ?

Great forum by the way!

Chris

david burton · Post by **david burton** » Thu Mar 06, 2008 9:53 pm

definitely start with the cheap fixes first!

RUM4MO · Post by **RUM4MO** » Thu Mar 06, 2008 10:14 pm

If I were you I'd stop driving this car right now, as its a 3 cylinder engine, running on 2 cylinders is not going to do it any good. Now nip down to your nearest VW garage and pick up a coil - supply them with as much info as you can ie VIN and engine number if possible. Then take it from there, in my limited experience, if a coil is misfiring then its U/S. I think that the coil is mounted on top of the plug - look at your Haynes workshop manual - if you don't have one I'd suggest you get one so that you can work out where things are and how exactly to get access to the coil. Carefully either place a bent bit or wire (welding rod) under the top of the coil and ease it up - you will probably need to release the coils wiring harness first. If you are careful you can ease them up by using a couple of screwdrivers. In the case of my wife's car, a 2003 1.4SE, no other coil has failed since I replaced one last year due to misfiring. While you are in there, why not check the plugs as well - find out what their NGK model number is - written on the plug body - and buy a new set at your local place (like for like only). I'm not suggesting that the plug caused the coil to fail - failing coils are expected during this period I'm afraid.

Ricochet · Post by **Ricochet** » Tue Mar 11, 2008 11:17 pm

Main dealer sorted this FOC on ours , replaced all three coil packs .
it was out of warranty but there was no quibble,( not even about service history).

thats got to be the fault , coolant sensor would not misfiring.

got to be worth a phone call .