Rough idle and "Check Engine Soon" light - FIXED

[nhill]

is this just a v8 issue? I had the same codes, possibly due to another issue I resolved, but wonder if I have the same elbow. Thanks for the thread though. It's these little situations that end up killing people....

 

[Cobra2top]

Perfect timing on this thread. I was coming home on a 5 hour trip yesterday and was pushing the 03 Eddie AWD 4.6 for most of it. I was hitting 75-80 mph (saw 90 at one time and backed off) which looking back was probably not the best thing for a 75K rig, but I just wanted to get home.

Anyway, she gave up on me literally 5 minutes from my house. After 5 hours of highway driving, she went into limp home mode as I was running stop and goes in the heat. The CEL lit and I know I was in trouble.

I went to Autozone this morning and they read similar codes except for P2195, O2 sensor stuck lean bank 1 sensor 1. After alot of research here I think I could have a hose leak instead.

When I shut the truck down, I hear what sounds like air escaping somewhere on the passenger side near the throttle body (removed the engine cover). It last for about 30 seconds and then "runs out" of air. Is this normal for the 4.6? Do you think I may have a hose leak somewhere? Common??

Let me know your thoughts. I want to try and fix this myself if at all possible. Autozone suggested I buy a new 02 sensor which I did for $50. Now I want to first try all options before replacing it (can return if not installed).

One side note, I did add a K&N filter about a year ago. Could I possibly have damaged the MAF with the oil in the K&N? There were not any codes reading MAF so I am not sure if cleaning the MAF could fix this.

Sorry for jacking this tread. but it is a similar issue. I can move it to a new post if needed.

Thanks! This is a great site!!

 

[EasyRhino]

Note - to troubleshoot a vacuum leak (this is really, really easy), all you need to do is to (carefully) use an UNLIT propane hand torch, like the kind used to sweat copper plumbing joints.

Start your engine, and using the UNLIT torch with the propane flowing, pass the torch (did I mention UNLIT) over all of the engine intake areas where a vacuum leak can develop, such as every vacuum hose, and every fitting that ties into the intake downstream of the MAF.

Any vacuum leak will draw in the UNLIT propane, causing the engine to increase RPMs. You can confirm the leak by removing and then restoring the torch tip to the location where the leak appears to be.

I do this annually on all of my cars. You might be surprised how many leaks (which cause performance to suffer) can exist without tripping a ECM message.

Just my .02 (and be careful out there).

 

[Cobra2top]

Thanks for the info. Looks like I need to head to Home Depot and buy a hand torch and see what happens.

Does yours make the noise of a ballon releasing air for about 30 seconds after you shut your engine off? I took off the engine cover and hear it now and dont know if it is suppose to be there. Maybe I missed it with the cover on?

 

[KingMJH]

Replacing the PCV Valve Hose

For all those that did this using an OEM part, how difficult is it to do it yourself, versus taking the part to a professional? I don't want to remove any parts only to find that I can not properly put them back on. Can some one include detailed instructions on how to replace the PCV valve hose? I've got a 2003 Mercury Mountaineer with the same rough idle problems mentioned. Checked out the elbow and sure enough, there is a hole in it, with the computer reading the same error codes. Thanks for the help, and GREAT post by Sybertiger.

 

[SyberTiger]

The vacuum line you are referring to that connects the PCV valve sitting in the passenger side valve cover to the intake is only held in place by the resistance of the line. In other words, there are no clamps. You just pull off the old one and push the new one on. If you plan to replace the entire assembly as I pictured in my post then you don't have to worry about destroying the old one. If you find you are having a difficult time remove the old one then just carefully use an Exacto knife and cut the old one off the intake fittings and the PCV. You might as well replace the PCV while you are at it. Just turn the PCV counter clockwise to remove it. You may use a cresent wrench on the PCV if you find you don't have enough finger/hand strength to turn it. Purchase the parts first and take a look at how they go on. It shouldn't take you more than 5 or 10 minutes to change that vacuum line and PCV.

 

[os1kne]

Great thread! Lots of good info.

 

[SESCOKID]

You guys saved me too as i was about to start changing out things to find the problem and tried finding the hose an djust like yours - there it was. Thanks again

 

[rtayloria]

Huge thanks to the posters here!!

You saved my broke arse much hassle and financial woes! I have a 02 sporttrak and even though the repair was that of a V-8 the 4.0 SOHC has the exact same setup. Inspected the hose visually and it looked fine so I replaced the MAF sensor and will be taking it back after I discovered the same hole ON THE UNDER SIDE of the hose. Had I not been curious enough to feel around and about get my finger sucked off, then I would have been looking at a huge bill from a mechanic that fixed the problem with added hours of labor! Purring like a kitten and looks like I will be hooking up and headed to the lake for the first time in 3 weeks. Much appreciated from a new member.

 

[Tito_146]

This is one of the reasons I have been a member of this forum for a few years now. Good thread. Good info. Don't have that problem now but I know it will happen.

Orlando

 

[teek]

I've heard of using an unlit propane torch to check for vac leaks before as well, I've never tried it myself though. I had a similar elbow leaking on the drivers side, it had a hole the size of a dime in it

 

[tonydp]

even though the repair was that of a V-8 the 4.0 SOHC has the exact same setup.

where would it be on the 4.0? any pics please if avaliable

 

[pmorkert]

I have a 02 Sport, 4.0 SOHC with 160k and had this exact problem. Couldn't find a replacement at the auto store, so I used radiator hose with a 90° bend and it worked perfectly.

 

[tonydp]

pmorkert, thanks for the pic. I didn't have a hole but it was severly dried out and cracked. Part store closed so i just taped it up to test. Smothed out pretty good. Off to get a proper hose in the morning.

 

[rtayloria]

tonydp,
The picture of the V-8 on page one of this forum topic is identical to my 4.0 2002 sporttrac design. If you do not see damage on a visual inspection be sure to feel the hose for the non visible sides. The hole that was in my hose was on the bottom side as well as a pin hole on the inside bending of the 90degree turn on the hose. When I went to AutoZone he checked for a replacement PCV valve (the entire assembly) and from that was able to match just the elbow. The cost was $5.99 for the hose he gave me, so if you are in doubt, I would first see if I could find a replacement, and then go ahead and remove the old and put on the new, no clamps, clasps, or anything hold this elbow, I assume the pressure itself hold it in place.

 

[SESCOKID]

You don't happen to have a autozone part number for the elbow?

 

[tonydp]

i notice that it idles perfect when cold but once up to temp still shakes a bit.

 

[rtayloria]

Reply on the hose part #

SESCOKID,
The part number best I can tell is 3009 on this particular hose. It was the match for the entire PCV replacement unit.

tonydp,
The one thing I would suggest is to check the hose once the motor is warm. What I found on mine was that the heat softened the rubber enough that it caused it to collapse in the bend of the 90 and restricted airflow causing the bad idle. When you have ran the engine long enough to heat it up, get to the hose and gently pinch the bend and see if the rubber does not feel extremely soft, when I squeezed the hose before replacement mine collapsed completely and pulling the hose off to replace when it was warm was like pulling warm taffy, although when it cooled it took its original shape. Hope this helps.

 

[tonydp]

thanks for the part # S-3009, I'll have to get it next time I'm i the US, unless someone want to ship me one

 

[SESCOKID]

Thanks,
i'm off to autozone - i don't know how long my tape is going to hold.