Choppy acceleration

Cossack · Post by **Cossack** » 01 Sep 2008, 12:05

Hi

I am experiencing something I can't quite put my finger on. My 02 S60 T5 runs great, but recently I noticed some strange hesitation/choppiness while in the upper range of acceleration. In other words, when I floor the pedal, I can sense some choppiness, almost as if the injectors were really dirty. When this happens and I keep the pedal down, the check engine light eventually starts blinking for a few seconds.

However, it accelerates fine up to about 80 to 90% of the gas pedal range, and I can hear the turbo kicking in. The car otherwise drives great, idles very smoothly.

Any thoughts on this? I am stumped!

Thanks!

Post by **MadeInJapan** » 01 Sep 2008, 12:07

How many miles on your car and when was your last tune-up?

Cossack · Post by **Cossack** » 01 Sep 2008, 12:10

It has ~ 143K miles, last tuneup was over two years ago.

I should also mention that I drive it quite a bit, 35K+ miles a year.

Post by **MadeInJapan** » 01 Sep 2008, 12:28

I would check the easy stuff first....plugs come to mind...you're probably in for some new ones (2 years and 35K miles a year= 70K miles??). Plugs should be changed a minimum of every 50K miles on these cars, and often sooner (even according to Volvo literature). Stay with OEM (Volvo) turbo plugs ( www.fcpgroton.com sells them for cheaper than the dealer) and make sure they're gapped to 0.028 or even less (down to 0.026). My guess is that these are worn out and gap has expanded over time thus at higher gas (and spark) demand, they aren't doing their job.

Cossack · Post by **Cossack** » 01 Sep 2008, 13:11

OK, thanks MIJ. I'll give that a try and let you know.

I appreciate the help.

Cossack · Post by **Cossack** » 01 Sep 2008, 18:06

Hi again

Great advice! Just changed the plugs, they were quite eroded and rounded. Problem is gone.

Thank you so much MIJ!!!

Post by **MadeInJapan** » 01 Sep 2008, 18:09

No problem...your issue sounded very familiar.