Focus Fanatics Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
109 Posts
Discussion Starter #1
Hopefully you guys can help me narrow down this issue I've been having. I have a 2004 SVTF that has had a weird habit of hanging revs when coasting with clutch in to a stop or when in neutral. The revs will hang at about 1100 - 1500 and then after a few seconds will eventually return to the correct idle speed. I have replaced the TPS and IACV and the issue persists. I recently tuned the car through RPS, and the tune has had no effect on this specific behavior. The tune fixed numerous other weird things about how the car runs, but this is the only thing I can't seem to figure out. I've tried a few different part numbered TPS's and all of them do the same thing. I've cleared the ECU 3 times since tuning in case it needed to "relearn" the parts, but nothing seems to fix this. Let me know what you think.
 

·
Vince your Moderator
Joined
·
5,074 Posts
PCV hose leak/collapse
 

·
Registered
Joined
·
109 Posts
Discussion Starter #3
Yeah that's one thing I haven't checked yet. Where is that on the SVT, and is it just the hose that needs replacing, or are there other parts too?
 

·
Vince your Moderator
Joined
·
5,074 Posts
Pull and inspect the rear(longer)hose for cracks and or, "squishiness" first.
 

·
Registered
Joined
·
109 Posts
Discussion Starter #7
Sounds good. It goes from the rear of the block to the underside of the intake manifold? I imagine with 181k miles that it's likely due for replacement.
 

·
Registered
Joined
·
109 Posts
Discussion Starter #8
Looks like my rear hose has a tiny 1/8" crack in it, and is pancaked out in one section. I imagine the vac from the engine must be closing it or something. As far as the elbow goes, I noticed some oil around it. Should I replace that one as well, and is there some kind of o ring in there I need?

 

·
Registered
Joined
·
109 Posts
Discussion Starter #9
Found it. It's the "grommet" for the pcv. Couldn't find it because I was looking for "gasket".
 

·
Vince your Moderator
Joined
·
5,074 Posts
Replace as needed.
 

·
Premium Member
Joined
·
21,250 Posts
Some rev hang is normal, yours seems to be a bit high. Newer cars are designed to hang revs in order to make gear engagement easier, so it won't drop to normal until you come to a stop even when it's running like it should be. It should only hang around 1k rpm though, so yeah, the issue you found is what is causing it to hang so high.
 

·
Registered
Joined
·
109 Posts
Discussion Starter #13
It would appear the dealerships all have the wrong part listed for the SVT PCV valve. They ended up selling me one for a duratec motor :(
Good thing Autozone had a Fram PCV for $3.
 

·
Registered
Joined
·
109 Posts
Discussion Starter #14
Replaced the pcv hoses and valve, and received a tune update. It's still doing behavior. I took a video on my phone. I'll try to post it.
 

·
Registered
Joined
·
109 Posts
Discussion Starter #16
bump for any more suggestions as to what might be causing this. Still happening. Just removed and reinstalled the intake boots last night to make sure there was no leak there; behavior stays the same.
 
1 - 16 of 16 Posts
Top