engine light, again

[rockdrummer4]

Hey lads, end of last july engine light came on, car was a bit juttery... obd reader was saying coil 3 was the problem.
brought it to mazda garage and they said it was plugs. Replaced all plugs and was fine up until week ago, when car juttered for few mins and engine light flashed, then it cleared and was ok for past week until today..
Obd reader saying coil 3 again.
any ideas? Is 2007 mx5 mk3, with 140,000 km..

[davith501]

Maybe try replacing coil 3 and see how you get on. Source some breakers save some cash..

[sidewaysreilly]

Have you replaced the leads yet ?

[rockdrummer4]

The Mazda garage determined it was the plugs the first time, cause they swapped the coils (i.e. switched coil 2 and 3), and the issue did not follow...

Could it be electrical? Shortly after the engine light came on last week I unplugged something from the lighter socket... Could this have caused a short or something?

Will Call garage later..

Cheers..

[rockdrummer4]

Rang garage, gonna swap coil3 and put it in say coil 1 to see if problem follows, if it follows to coil 1 then the issue is the coil, however, if it stays in coil 3 then its something else (not the plugs, they were changed 2 months ago)

[Steve]

where are you based? If it happens again and you are near Galway it might be worth visiting Jeramy in autoelectricalconcepts to see what he thinks.

[rockdrummer4]

Thanks Steve, based in Dublin!

On a side note, this is the same issue I had end of last July (misfire on cylinder 3), then got plugs replaced. A week later the starter motor burnt out and had to get that replaced. Then 3 months later have the same issue with misfire on cylinder 3 again.

Do ya think they are related, or just coincidence?

[sidewaysreilly]

Did you replace the plug leads ?

[rockdrummer4]

So garage swapped coil 3 for coil 1 and the issue followed to coil 1.. gonna replace the coil.

My question is, do ya think they were right to change the plugs the first time? Could it be possible that I had a dodgy coil all along (strange that it did not act up for 3 months). The old plugs were on about 36,000 km old, so probably didnt need to be changed?

And do ya think the issues I have had - cyclinder 3 misfire (plugs replaced) - starter motor burning out (replaced) - misfire on cyclinder 3 (coil replaced) - are in anyway related, or is their anything bigger I should be looking at. All of the above occured in a short 3 month period!

Just worried I may have a lemon on my hands Have owned mk1 and mk2 combined for 6 years and have spent more money in the past year on mk3 than the 6 years combined for the older models !! Never should have changed...

[MX5Spares]

Hi ,hate to say it but mk3 ........

[rockdrummer4]

Hi ,hate to say it but mk3 ........

Yes I agree now, should never have got rid of the MK1

Problem started again, quick history:

- July misfire cylinder 3 - replaced plugs -> problem gone for about 3 months
- October misfire cylinder 3 again - swapped coil 3 and coil 1, issue followed, replaced the coil
- December misfire cylinder 3 again - is not too bad so far, only appears to occur badly (engine light comes on and car juttering) when petrol tank is low (if this has anything to do with it!). However, have also felt a few small jutters while driving with full tank!

Any ideas, please help this is really annoying now?

Thanks, C

[rockdrummer4]

Garage have recommneded using Dipetane.. see if this helps..

[sidewaysreilly]

Don't use that shite, use Injector cleaner. Did you replace the plug leads?

[MX5Spares]

Dipethane is brilliant cleaner as I have have being using it for approx 10 years now and it is top of the range but I think your problem is electrical ,possibly the coil loom.Common problem on mk3 ,s.

[rockdrummer4]

It was a broken seal between the air intake part and the cylinders - this was causing the intermittant misfire...

Getting fixed today.

Thanks, C