Ranger XLT with Very rough idle

[Pcola38]

Hi. I am new to the site but I just purchased a 2003 Ford Ranger XLT with the 3.0L V6 Flex Fuel engine. It has 200,000 miles on it. It runs great but idles rough. I have installed new plug wires, new plugs, a new fuel filter and have put injector cleaner in the tank. Still idles rough. Any suggestions on what to do next would be welcomed. RPM at idle is 750. I did have the door ajar light on but read on here about the WD-40 trick and it worked great. I believe I might have a noisey rear wheel bearing but will attack that later after I have successfully eliminated the rough idle.

 

[Tbars4]

..You may need to clean your Idle air control (IAC) or may have a vacuum hose with a leak..

..If you had your location under your name, others in your area may be able to better assist you..

 

[Pcola38]

IAC recommendation

Thanks so much for the IAC recommendation. I will tackle that tomorrow and report the results. Also, I have updated my profile.

 

[Red FX4]

I don't know if the 3.0L has a similar issue with the PCV elbow that the 4.0L SOHC does but you might take a look to check it out. I had a rough idle and it ended up being a rubber elbow near where the PCV tube connects into the throttle body/intake. That rubber elbow degraded from the heat and oil fumes resulting in it collapsing and cracking. This caused a serious vacuum leak and caused the rough idle. After looking in to it further I found it is a common failure in with the 4.0L SOHC engine. I replaced it with a silicone elbow and it should last longer than the truck.

I have not heard of the 3.0L engine having this problem but that does not mean it can't happen. I found starter fluid work well in finding vacuum leaks. It is very flammable so care needs to be taken when using it.

 

[Pcola38]

pvc and vac leaks

Gary,
Thanks so much. I will check both of these tomorrow when I am cleaning the IAC and post the results.

 

[Pcola38]

2003 for ranger with rough idle

Today I checked for vacuum leaks and found none. I did check the 90 degree hose going to the pvc valve and it looked realitively new and no cracks in it. I did pull the hose off while the engine was running and it did run rougher than a cob. I am now ready to remove and clean the Idle Air Control valve but not sure what it looks like or where it is. Is it located where the breather hose fits into the top of the engine and looks like an aluminum module with a gasket? The last ford I worked on was my 1936 flat head V8 with mechanical brakes. There is a lot of stuff under the hood on this 2003 Ranger. I ordered a repair manual but it is not in yet. Thanks in advance for your help.

 

[Pcola38]

I just found a wealth of pictures on this forum for the IAC and can now remove it an clean it. Will post results tomorrow.

 

[Pcola38]

Now runs and idles smooth

Today I cleaned the IAC and while I was at it, I changed the PCV valve. The IAC was really black inside with carbon buildup. I used the fuel components spray from autozone to clean it with and also used Q-Tips. After changing the PCV and reinstalling the IAC, the engine idled smooth but ran rough at about 3000 rpm. I decided to go to autozone and buy a new IAC but on the way there in the truck, it smoothed out and ran great. There must have been some cleaning fluid still in the IAC that had to be dissapated. I had a minor squeek of the Serpentine belt in the mornings so while I was under the hood, I sprayed belt dressing on it and guess what - it got worse than ever. I bought a new belt and I am now going to look on the forum for the correct routing and attempt to replace it. Hopefully, this will not be a show stopper.

 

[Tbars4]

..The computer was compensating and running the truck based on the old values..Once the truck started running with new values, the computer compensated and your truck smoothed out...

...You will hear people on here disconnecting their battery cables for 15 minutes..This allows the vehicle to start with factory values which is usually quicker than say 50 miles or "X" number of starts before the computer starts correcting it's values, after a vehicle has been running ill for a while..

 

[swshawaii]

I had a minor squeek of the Serpentine belt in the mornings so while I was under the hood, I sprayed belt dressing on it and guess what - it got worse than ever. I bought a new belt and I am now going to look on the forum for the correct routing and attempt to replace it. Hopefully, this will not be a show stopper.

No under hood decal on your Ranger? BTW, NEVER use dressing on a serpentine belt. LOL

http://www.autozone.com/autozone/re...6b43f8036df28&partId=0996b43f8036df28#hd1-1-2

 

[Pcola38]

Ford Ranger 3.0

Thanks for the information on removing the negative battery cable for 15 minutes. I wish I had been smart enough to do that.
My new problem now is not related. I am now trying to replace the serpentine belt and at the moment, it is winning and I am losing. I had a fit finding a wrench to fit the belt tensioner with the minimal room between the radiator and the pulleys but I finally used a very long 5/8" combination wrench but now trying to put the new belt on I am beginning to believe this is not a one person job. For the life of me, I can't keep the belt on the pulleys as I go from one to the next. I started out by getting the belt over the fan blades but now am not sure that was a necessary step. I gave up this evening because of dark but will start again tomorrow. If I can't get it on, I am about two miles from a repair shop and may try to drive it there if it does not overheat. I am learning a lot as I fight this beast but I truely am running out of fun.

 

[swshawaii]

The belt tensioner spring is very strong, a second set of hands always helps.
Sure you have the correct belt? Using a long cheater bar/pipe may be easier. GL

 

[Pcola38]

serpentine belt

Hi folks. I got help from my Son today and the second set of hands on that serpentine belt really helped. We put it on in less than ten minutes. I did remove the air tunnel in order to get to the pulleys easier and the long 5/8" combination wrench easily moved the tensioner. The hampster cage wheel noise is gone and I have no more squeeks. I will NEVER spray belt dressing on a serpentine belt again. Thanks so much to all for your suggestions and support.