scottydwrx

Just had a 4 year/ 40K service done on my Hawkeye WRX at a Subaru Dealer this morning. Also got them to change the spark plugs as well which I supplied (Brand new NGK ILFR6B as per the manual).

Engine ran fine prior but driving home it started hestitating and jerking under acceleration (fine if I keep it under 3000rpm) and the engine management light is flashing whilst this is happening but then goes out if I drive steady.

Spoke to dealership and got to take it back in first thing monday (as they are only open half day today)

So any ideas?? Possible loose coil packs/leads?
As far as I am aware nothing else should have got changed or adjusted on the service except clutch/brake fluid and the oil/filter.
I am sure they will try to blame the spark plugs that I supplied but they were brand new.

barnshaw

iTrader: (1)

spark plug could have worked lose, coil pack, gapping might be wrong on the plugs? MAF failure?

scottydwrx

That was my first thought either loose plug or coil pack.
With regards to gapping I thought they came ready gapped and you are not really supposed to change them?

joz8968

iTrader: (13)

The 'obvious' thing would be the plug gaps, seeing as it's playing up post-plug change.

They are usually in the ball park area out of the box, but should always be checked/adjusted before fitting, to be certain...

scoobzie

spark plugs never come gapped whip them out reset the gap and see how you get on

scottydwrx

Strange that the user manual says that they shouldnt be gapped?

So would a slight gapping problem cause such a significant hesitation / misfire and cause engine light to flash on & off?

Also will they simply be able to plug in a code reader etc. and see what the problem is straight away or will it be a long wait!

Thanks for the replies

bigarf

iTrader: (67)

more than likely a loose coil pack or a loose connection to the coilpack.could even be that they have cracked a plug when fitting.

scottydwrx

Just had a quick look under the bonnet and the spark plugs look pretty unaccessible to say the least!
What has to come off in order to gain access down to the plugs? - Just wondering if something else might be loose (like airbox/MAF connection) or not put back properly?

scottydwrx

Update:

Turned out there was a misfire on cylinder 2.
Changed the spark plug for another new one and everything is back to normal

So turns out it was a faulty spark plug that was brand new straight out of the box.

Good thumbs up to the dealer RN Goldens at Huddersfield too for not charging me any labour to swap it Great service and very helpful

joz8968

iTrader: (13)

That could have been really annoying - as you could have been left head scratching for a while.

But good on you for not assuming they were okay, and sussing it.