Juddering under hard acceleration
 

Hi everyone,

I have just picked up a used 2001 Subaru Impreza 2000 Turbo AWD with 90k on the clock. When driving it and under reasonable acceleration it is smooth. However when pushed hard, although it continues acceleration, it judders at high revs for a bit. Is this a serious problem or one that is usually resolved by a good full service and replacement of spark plugs?

Any pointers welcomed, thanks in advance.

Dominic

I'm no expert but juddering at full throttle could be caused by a boost leak.

Thanks , I have booked it in with a subaru specialist to check it through.

obviously impossible to be sure from a written description but sounds like you are experiancing spark misfire, the spark is finding a quicker/easier route to ground rather than jumping the electrode.. could be old or wrong plugs, too large gaps or coilpack issues.

Keep it off boost until sorted as a misfire does generate very high cylinder pressures.

Simon

Dyno Demons on the Wirral have had the car for the day and it ended up to be a mix of things. The car was overfilled with oil, some overspill into the boost unit. Also the spark plugs were old and burnt out and the cables attached to them were worn out. In all, not a good shape, however all rectified now with great service from the Dyno Demons!

Worringly, checking the log book a Subaru dealer serviced the car up to 55k, then two private dealers since and no one had changed the spark plugs etc as they were all original parts. Very very worrying! I am sticking with Dyno Demons!

Hi from what i am told the original subaru spark plugs are supposed to last for 100 000km i think thats the denso irredium so maybe thats why they were never changed but still theyshould have been inspecting them at evry service interval