Multiple cylinder misfire on 2006 1.4 BBZ engine

[warp_speed]

Looking for some advice. I've got a SEAT Ibiza (56 reg) 1.4 with BBZ engine and its recently came up with the engine management light flashing. Plugged in the VCDS and it came up with multiple cylinder misfire detected with fault codes for cylinder 1, 3 and 4. I've changed the coil pack on cylinder 3 to see if it would help the situation but no change, group 14 and 15 shows multiple counts of misfire across all 3 cylinders. Any other ideas what this could be.

[Sam]

The ignition leads run in the grove of the engine cover which often causes them to deteriorate - Edit: I may be talking crap here, I might be thinking of the Polo 1.4 MPI not the BBZ in the 1.4 16v Ibiza (I have both vehicles!). The next part will work regardless though, it'll hopefully eliminate the leads being an issue.

Making a note of which lead goes where, remove the lead from #2 and swap it with one that you know is misfiring.

See if the misfire moves.

[warp_speed]

The ignition leads run in the grove of the engine cover which often causes them to deteriorate - Edit: I may be talking crap here, I might be thinking of the Polo 1.4 MPI not the BBZ in the 1.4 16v Ibiza (I have both vehicles!). The next part will work regardless though, it'll hopefully eliminate the leads being an issue.

Making a note of which lead goes where, remove the lead from #2 and swap it with one that you know is misfiring.

See if the misfire moves.

It has coil packs, no HT leads. But have checked the wiring to the coil packs and they look ok.

[Sam]

I'm confusing my vehicles, apologies.

You say you changed the coilpack on #3 but not the others. For the sake of £30 it might be worth changing all 4.

When was it last serviced, how old are the plugs and finally what were the exact codes stored?

[zollaf]

i would try some new sparkplugs as well.

[Rob69]

Compression test maybe worth doing if no joy with plugs and packs.

[warp_speed]

Compression test maybe worth doing if no joy with plugs and packs.

Next on my list of things to do, any idea on what the compression value should be?

[zollaf]

a petrol should be around 150 - 180 ish, but what you want are even compressions across all 4. if one or more are 20 psi out, then you have found a potential problem.

[warp_speed]

I'm confusing my vehicles, apologies.

You say you changed the coilpack on #3 but not the others. For the sake of £30 it might be worth changing all 4.

When was it last serviced, how old are the plugs and finally what were the exact codes stored?

Serviced around 5 months ago. Plugs changed around 20k and I used a standard handheld scanner (VCDS laptop not available at the time) and it reported misfire on cylinder 3, hence got a coil pack for it (£43 at TPS). Got home and connecting up VCDS it reported the following fault codes.

P0300 16684
P0303 16687
P0304 16688

I checked out group 14 and 15 of VCDS and it showed multiple misfire counts across cylinders 1, 3 and 4, nothing for 2.

[zollaf]

20k on a set of plugs, change them..

[warp_speed]

20k on a set of plugs, change them..

really :D, I thought plugs lasted longer. But why risk it, all my other options sounds a lot more expensive.

[zollaf]

i don't know the interval on your car, but some can do 50k, if they are platinum tipped. i suspect yours are not, in which case anything over 6k is a bonus. its not long ago that plugs would be changed on every srrvice , every 3k.

[warp_speed]

Well looks like I found my problem. My neighbour is an Audi tech and brought his VAG compression testing tool. Anyway print out reads

Cylinder1 14.6
Cylinder2 10.3 ---- one that's not misfiring
Cylinder3 14.2
Cylinder4 13.3

Head off and to an engineering work I think. I really did think I dodged a bullet buying a later SEAT Ibiza, but looks like burned valve/stuck valves is still an issue with the BBZ engines and only 46k miles on the clock, as if that means anything these days. ****!!!

[Rob69]

Look around for full head exchange kits, I think it'recommended to change the hydraulic lifters etc at the same time.

[warp_speed]

Exchange kits, what are those. If your talking about a head from Vag they about 1k

[Sam]

:(

[warp_speed]

While the head is off, other than the potential valve being fixed, what else needs to be done. I heard about valve stem oil seals and a whole bunch of things?

[Rob69]

I meant an exchange head from somewhere else, seen some around 350 quid complete. I think you'd be wasting your time just doing the one valve and would be better getting an exchange head. Also think you need new bolts, lifters, maybe consider timing belt kit, water pump as well while you're in that deep and if you plan on keeping the car.
Exchange kits, what are those. If your talking about a head from Vag they about 1k

[warp_speed]

Yeah I was thinking about that but BBZ engine heads are as rare as hens teeth.

Got a quote from my local engineering company, they suggested changing the valves that are causing the problem and the valve guides as they seem to be prone to sticking. Only quoted for a skim, strip with valve and seats cleaned and reseated with two new exhaust valves comes to a total of £120+VAT, never provided a price for changing the valve guides, they need to see what needs to be done before quoting figures.

[Advanced-Tuning]

Non genuine coil packs can cause all sorts of havock as well. We have learned from this and now only replace with Vag parts, which you'll find at TPS very reasonable

[Inkubate]

Had to do just this same job on my BBZ Ibiza over the summer - mine at approx 47K and cylinder 3! I took a punt on a Fabia BBZ head from ebay which actually turned out good so did some work myself and some outsourced. Mainly did it this way so that it was a quick swap at the time rather than taking the head off then being without the car whilst work was being done.

If you need any part numbers let me know because I still have them listed as you need a new crank pulley bolt etc. Deffo do the cam belt as these are due at 45K anyway. I got an Elring head gasket set that included the valve stem seals so did everything I could.

Fabia BBZ manual states 7 Bar as wear limit for compression and max 3 bar between cylinders. New should be 10-15.

Chris

[warp_speed]

Yeah, took the head off and sent off to an engineering works. Stem guides/sleeves were burned, so 8 exhaust sleeves replaced, valves and seats re-lapped. Cost about 180 inc vat, they also included Elring gasket set and head bolts. No way I'm forking out nearly £12 for each head bolt (x10). Anyway parts cost another £500 (water pump (£46), cam sealant (£66), oil, coolant (£22 for 3 litres), timing belt kit (£205), aux belt tensioner (£100), aux belt (£27). So all in say £650 for the work. Car runs like a dream now, a lot smoother than before.

[Inkubate]

Glad that you sorted it too. The engine like you say is lovely once sorted - silent once fully warmed and idling. And has a bit more go.

Some people attribute the problem to not using 98 octane fuel which these are designed for and others say that the valve guides are just not really up to the job - on mine it looked like this caused the seats to misshape and ruin the seal. I now use 98 fuel just incase as its not a job you want to do twice as very expensive!