[OLS]

Morning all, I had poblems with the emissions light on me Astra MK4 1.6 51 plate Auto (See this thread) so I took it to the garage and asked them to give it a reading, they asked me to come back in an hour as they were busy. When I went back, they said the reading had reported a missfire on on 3rd Cylinder so they had replaced the Spark Plugs (I wasn't happy, I only asked for a reading not for them to fix any problems as I know I could of changed them myself for 1/4 of the price!!!). They said light was off now, uually if this is the fault its the Plugs or the Coil pack, but as the coil pack is £150 ish plus VAT and Fitting, then they usually try the plugs first. Light was off for 2 days and its now back on so the changing of the plugs has not worked.

Now they said keep recipt as they will do free readings if it comes back on again but Im wondering with the fault they reported, shall I purchase a coil pack and get it fitted myself (my dad can do this type of thing) or shall I get it read again first and ask for a print out (they didnt give me one the first time, are you supposed to get one.

The plugs and Reading cost £75 so don't want to fork out for them to just fit a coil pk if this isnt the problem.

Can anyone offer any advice??

Thanks

 

[bigtee]

End of the day thats your choice.

If it's not the coil pack and something else you have wasted more money.

 

[Delbert]

Sounds like the modern computer faultfinding technique - just change one thing at a time until the fault disappears! Modern computer assisted faultfinding is so much better than the old investigative engineering of the past.

And scarcasm is my middle name.

Anyway, as for the coil pack, I understand each coil supplies two plugs (a plug on each end of the coil, a technique that was first used on multi-cylinder motorbikes I recall), such that there'll be a spark for every TDC position of a particular piston. As such I'd have thought there's a good chance that a misfire caused by a faulty coil would very likely affect two cylinders.

 

[Boroboy]

Morning all, I had poblems with the emissions light on me Astra MK4 1.6 51 plate Auto (See this thread) so I took it to the garage and asked them to give it a reading, they asked me to come back in an hour as they were busy. When I went back, they said the reading had reported a missfire on on 3rd Cylinder so they had replaced the Spark Plugs (I wasn't happy, I only asked for a reading not for them to fix any problems as I know I could of changed them myself for 1/4 of the price!!!). They said light was off now, uually if this is the fault its the Plugs or the Coil pack, but as the coil pack is £150 ish plus VAT and Fitting, then they usually try the plugs first. Light was off for 2 days and its now back on so the changing of the plugs has not worked.

Now they said keep recipt as they will do free readings if it comes back on again but Im wondering with the fault they reported, shall I purchase a coil pack and get it fitted myself (my dad can do this type of thing) or shall I get it read again first and ask for a print out (they didnt give me one the first time, are you supposed to get one.

The plugs and Reading cost £75 so don't want to fork out for them to just fit a coil pk if this isnt the problem.

Can anyone offer any advice??

Thanks

If you have a cylinder misfire on cylinder 3 could be for a number of reasons. Electrical or mechanical failure. The garage could have swapped a plug over, instead of buying a new one. Then seen if the cylinder misfire had changed to another cylinder.
After changing plugs, I'd go for changing leads or coil pack.
Vauxhall set of 4 leads cost's around £80 & the amount you have already stated for coil pack. I couldn't buy a copy set of leads that would fit properly (including a bosch set). Where the leads join onto the coil pack (not long enough), was the problem.
I had a misfire with my 2000 1.6 Astra 8v recently. I changed the coil pack. Cost me £25 from a breakers & came with 1 month a guarantee. Fixed the prob, car now 100%. Easy diy change, easier if you take battery off to the change coil pack. Takes less than 30 mins. Torx heads I believe to get coil pack off.

 

[gashy]

I personally would go with the coil pack as they seem to be crap. i also had misfire on cylinder 3 and changed my coil pack and was sorted. phone Autovaux or to a trip to local scrappy

 

[spookyman60]

on 1.6 engine it isnt combined coil per two plugs its coil per plug as far as im aware and what the manual says