Vauxhall astra petrol c.2003 runs on 3 cylinders

[Nige F]

As title - suddenly started running on 3 - lumpy as **** Where should I start looking ? Over 100k miles . Thanks guys.

 

[pete50]

Coil pack, plugs. After that it gets complicated.

 

[Mottie]

Plugs out, see which one is wet, change it, if still no luck check plug lead for spark. That’s for starters and should sort 99% of problems like this unless it’s something bigger - loss of compression - burnt valves or maybe a faulty injector.

 

[Burnerman]

Presumably the engine management light is on?
A scanning tool will get you a bit closer - and you may need it to put the lamp out.
John

 

[Nige F]

Yes the management light is on - I'll have a look @ the plugs and take it to a mechanic for scan.

 

[lostinthelight]

Theres plenty of code tools out there if your that way inclined for less than garage cost of hooking it up .
An interface for https://www.swvaux.com/op-com-software-download-installation/?v=79cba1185463 isnt expensive . Not tried it myself but mentioned on the Corsa forums a bit.
https://www.thecorsa.co.uk/forum/technical-help/mechanical-help/1162-which-fault-code-reader

 

[Nige F]

Plugs out, see which one is wet, change it, if still no luck check plug lead for spark. That’s for starters and should sort 99% of problems like this unless it’s something bigger - loss of compression - burnt valves or maybe a faulty injector.

Update - thought I'd check the plugs by removing the leads one @ a time to see which cyl. was misfiring. Pulled 1 up about 25mm , still in the protective tube - started car and it ran smooth - the spark jumped the gap and helped that plug fire - I'll take it out ans see condition later

 

[Burnerman]

Maybe just an HT lead fault after all Nige....I guess this car has the 'block' type coil pack and is either 1.4 or 1.6?
You'll maybe see sparking or hear a 'click' as the electricity jumps to earth.
John

 

[Nige F]

Indeed, the engine light went out too ! It's just a stop gap car ( for my D.i.L ) until the MOT in August. No hope then because it smokes like a good un and has probably killed the cat . And I'm repairing her Ka too - new water pump and thermostat. I haven't touched a car for years - now this !

 

[Nige F]

Maybe just an HT lead fault after all Nige....I guess this car has the 'block' type coil pack and is either 1.4 or 1.6?
You'll maybe see sparking or hear a 'click' as the electricity jumps to earth.
John

You're right on both counts - block and clicking. 1.6.