Symptoms of a valve seat about to drop?

[TheGlassMaker]

If you have a CEL go to your local parts store, they can let you know the code for free. For a more detailed scan take it to your local dealership for probably 60 bucks they can give you a more detail scan. if you already got a scan disreguard this. I not sure there is a way to bench test the iac. With needing a vacuum and electrical supply. I have a newer iac if your interested. I put it on my car just a few weeks before the engine went. Let me know if you want it.

Sent from 34.0764° N, 118.4296° W

[GUM85]

I guess you can test it electrically but not mechanically. Autozone's web site says to test the IAC on 2000-2005 focus disconnect the two pin electrical connector, using a digital multimeter do a resistance test at the two pins on the IAC valve electrical connector and you should get a reading between 6-15 ohms if the reading is out of that range replace the valve. I did this test on the IAC valve on my car and got a 0 ohms reading. If I did it correctly than my IAC valve is no good. I just don't understand why it would run worse after I took it off and cleaned it.

[Donnyd21]

Originally Posted by GUM85

I guess you can test it electrically but not mechanically. Autozone's web site says to test the IAC on 2000-2005 focus disconnect the two pin electrical connector, using a digital multimeter do a resistance test at the two pins on the IAC valve electrical connector and you should get a reading between 6-15 ohms if the reading is out of that range replace the valve. I did this test on the IAC valve on my car and got a 0 ohms reading. If I did it correctly than my IAC valve is no good. I just don't understand why it would run worse after I took it off and cleaned it.

You could have logged the "gunk" in where the piston screw is causing it to not work properly anymore.

If any of you guys have suffered the vlv drop issue I have lots of good used OEM piston and rod assemblies if you need any, just PM me.

[GUM85]

I wish I had a service manual so I knew the correct Ford way of testing the IAC valve. I'd just really hate to spend all of that money on one and it not fix the problem.

[TheGlassMaker]

I honestly don't think it was more than 50 bucks. To be honest if it runs worse now than it did before and that's the only thing you touched. Then it sounds to me like it needs replaced. I would understand if the part was 100 or more but for less then 100 even if the part is it bad yet putting a new one isn't going to hurt anything it would prevent problems later down the road.

Sent from 34.0764° N, 118.4296° W

[GUM85]

I guess I'll go ahead and replace it. I'll give an update and let you know if that solved the problem or not.

[TheGlassMaker]

Yes please keep us updated.

Sent from 34.0764° N, 118.4296° W

[mikebontoft]

Now that I look at your code again, you said "bank one" not cylinder one. Sorry, I read it wrong.... though I'm surprised no one caught me on that.

Actually, looking at it again you called it cylinder one in a later post. that is incorrect.

Engine use each manifold as a bank. Since this 4 cylinder only has one manifold, there's only one bank. So, that means your whole engine is lean, not a single cylinder. It may very well be the IAC, though I'm surprised you haven't seen another code for the IAC position.

Make sure that gasket surface is clean. spotless. You probably tore up the old gasket and just reinstalled it. That's probably why it runs like crap now. Since you'll have to take it off now, its up to you to test or replace it.

Keep in mind this still doesn't change the fact that your intake manifold gasket(s) could be bad.

[lmcd314]

po171= vacuum leak it came on when my egr valve went ($30 part) check for hissing sounds, grab hoses wiggle things, see if the hissing gets worse or goes away, or if it runs different. you can also spray brake cleaner near suspected parts. (be careful, not really recommended, fire hazard) good luck

[Jalenarii]

Originally Posted by GUM85

I was wondering if there's any tale-tale signs that a valve seat is about to drop? The reason I ask is because my 02 LX has started to idle really rough. It started out as a very mild hiccup in the idle but has increasingly got worse to the point that it idles extremely rough when at a stop light or in park to the point that it will usually die unless you keep one foot on the brake and give it a little bit of throttle with the other. I've noticed it idles fine upon start up when the engine is cold but once the engine reaches operating temp the rough idle kicks in. It still drives fine with no noticeable loss in power. Not sure what's going on with her?

I had this same issue at a stop light it would idle into shaking the whole car, then die. Two days before I was going to take it in, it wouldn't start. I identified a bad fuel pump. Changed that out and the harsh idle is gone. Not sure if that helps but it fixed my problem.