Hi All,

Recently purchased on approx 70k miles and running perfectly for about 5k miles then started to run a bit rough, particularly at idle, then engine warning light came on. Ran a scan using a friend's Carista which identified the following fault codes:

 

15125 - Cyl.1: Misfire Detected

15131 - Cyl.3: Misfire Detected

16507 - Cylinder 1: Combustion misfire during combined operation detected

16511 - Cylinder 1: Combustion misfire during intake manifold injection detected

 

Now I'm no mechanic so was hoping that someone that has either experienced similar faults or has the knowledge would kindly advise on likely causes and remedies.

 

Any help would be greatly appreciated!!

 

Ps first post so apologies if this has come up elsewhere or I've posted in the wrong place!

 

The codes are telling you that there is misfiring going on. It’s not telling you why! I would start out with checking the usual service items - have the spark plugs been changed recently? Engine air filter? And what do the spark plugs look like?

 

Thanks Nick, much appreciated! I have some service history but no reference to spark plugs or air filter change. Will start by replacing the plugs - a fairly cheap and quick fix that I can do myself, I've never changed an air filter but having just done a quick search it seems pretty easy👍

Welcome.

 

Fairly cheap and easy, do you have an ignition coil puller? Cheap.

They were due a change at 4 years / 40,000 miles.

 

What service record is there,

Has the Haldex had 2 services? 

The DSG is nearly due it's 2nd service.

11 hours ago, Drainpipes said:

Thanks Nick, much appreciated! I have some service history but no reference to spark plugs or air filter change. Will start by replacing the plugs - a fairly cheap and quick fix that I can do myself, I've never changed an air filter but having just done a quick search it seems pretty easy👍

Air filter is trivially easy to replace, spark plugs a bit more difficult because it can be tricky to extract the coil packs due to “sticktion” of the rubber seals on the plug stem. As mentioned, a coil pulled may be necessary. Be gentle, the plastic noses on the coil packs are not particularly robust. Check how to disconnect the coil pack wires before forcing the connector! The main trick is to push the connector in whilst operating the release tab, then whilst still holding the tab in, pull the connector off. If you don’t initially push in, the tab can be jammed.

 

In terms of diagnosing, I might have said “#1 coil pack duff” but since something on cylinder 3 is also troublesome it is probably not that - double failure unlikely. I have also heard of strange behaviour with dodgy crank or cam position sensors, but try the plugs first.

Based on that,  clear the codes swap coil pack 1 with coil pack 2 and give it a run. If you still get misfire cylinder 1 then swap the coil pack and swap spark plug 1 with spark plug 4.  If that doesn't work then its possibly an injector.

before spending any money swap the coil packs round on 1 and 3 with 2 & 4, and see of the misfire shifts.

If it does, its the coil packs and not the plugs 

2 hours ago, stevetdci said:

Based on that,  clear the codes swap coil pack 1 with coil pack 2 and give it a run. If you still get misfire cylinder 1 then swap the coil pack and swap spark plug 1 with spark plug 4.  If that doesn't work then its possibly an injector.

And bear in mind there are 2 injectors per cylinder.