Ford Focus Forum, Ford Focus ST Forum - View Single Post - rough idle, SOMEONE PLEASE HELP!
View Single Post
Old 10-15-2004, 03:25 PM   #2
soffiler
Registered User
 
soffiler's Avatar
 
Join Date: Sep 2003
Fan#: 372
Location: Sterling, CT
What I Drive: '03 ZX3 PZEV 5-spd Twilight Blue; '97 F-250 4x4 w/ 351 V8 & AT

Posts: 1,236
FF Reputation: 1 soffiler Good Standing Member
Buy-Sell-Trade Rating: (0)
Matt -

The combination of the hissing sound, the fact that it only occurs after warmup, the rough idle - yes, it ceratinly sounds like it could be an air leak, and the manifold is one of a few likely candidates.

One thing bugs me, however. For a fairly large air leak (large, totally subjective term, but I mean it's large enough to HEAR above the engine noise!) I would expect a Check Engine light with a code P0171 (system too lean bank 1)
soffiler is offline  
    Reply With Quote