cwackduck
New Member
- Joined
- Dec 6, 2010
- Messages
- 4
- Vehicle Year
- 2002
- Transmission
- Automatic
Hey guys!
This is my first time posting, but I VERY commonly come to this board when I have any kind of problems with my Ranger, and it's always been super helpful. I'm not super mechanical, but I'm a big do-it-yourselfer, and I need some help getting on the right path here, I think.
Within the last 2 months, my Ranger has started acting up and getting REALLY crappy gas mileage. I've tallied it up and it's getting somewhere around 11mpg. Prior to this it was getting about the average mpg and I haven't had much trouble with it. I've started a new job where I typically drive about 50 miles a day and the cost of the gas is starting to add up...
For starters, I have a 2002 Fx4, 4.0L v6, 31x10.50x15 and JUST rolled over to 149k on the odometer.
What's going on with the truck: Other than the bad mileage (which I'm assuming is a result of the problem) at around 35 - 45mph, the truck shakes like I'm driving on a gravel road. Typically it's when I'm in a slow zone where I have to just keep ~40mph. It almost feels like the truck is jerking-foward, not pulling smoothly. It happens a little when cold, but seems to be more noticeable when it's warmed up. At highway speeds it seems to go away, or at least be a little less shaky. It also idles rougher than I ever remember.
Since this has happened I've googled the hell out of the issue and visited this forum for answers. Here's what I've done so far:
All new plugs and wires, cleaned the MAF, put in a new PCV valve, replaced fuel filter, replaced the transmission mount, and yesterday cleaned out the IAC. Each helped a little but didn't fix the problem. The truck idles a lot quieter since cleaning the IAC (which was pretty dirty), but still idles rough at ~800rpm at rest. I've checked all of the vacuum lines (and elbows) I can think of and couldn't find any cracks. Also, the vacuum ball is still in one piece, and I haven't modified anything on the truck.
It was after cleaning the IAC that I noticed my truck making a hissing noise right when the throttle is pushed in that I hadn't noticed before. It seems to be coming from behind the throttle body area I think. I made a video of this that can be watched here: http://www.youtube.com/watch?v=-Vp_gHKPS_U
At this point I'm thinking it's got to be a vacuum leak SOMEWHERE in this thing, but I'm not 100% where yet. When I get a little more confident and have a fire extinguisher handy, I'm thinkin of trying the "carb cleaner test" around the engine to find any hidden leaks that way.
So, from this short novel I've written here, does anyone have any other suggestions for anything that I can try that I'm obviously overlooking here?
I'd appreciate it!
Edit:
Also, one thing I forgot to add. Before I cleaned the IAC, I "tested" it but unplugging it while the engine was idling. I'd read on here that it was one way to test if it was working. Some said if it was working, the idle would get REALLY bad, but in my case, the engine shut off entirely and wouldn't start without the IAC plugged in. Dunno if this is relevant or not, but just thought I'd throw it on here.
This is my first time posting, but I VERY commonly come to this board when I have any kind of problems with my Ranger, and it's always been super helpful. I'm not super mechanical, but I'm a big do-it-yourselfer, and I need some help getting on the right path here, I think.
Within the last 2 months, my Ranger has started acting up and getting REALLY crappy gas mileage. I've tallied it up and it's getting somewhere around 11mpg. Prior to this it was getting about the average mpg and I haven't had much trouble with it. I've started a new job where I typically drive about 50 miles a day and the cost of the gas is starting to add up...

For starters, I have a 2002 Fx4, 4.0L v6, 31x10.50x15 and JUST rolled over to 149k on the odometer.
What's going on with the truck: Other than the bad mileage (which I'm assuming is a result of the problem) at around 35 - 45mph, the truck shakes like I'm driving on a gravel road. Typically it's when I'm in a slow zone where I have to just keep ~40mph. It almost feels like the truck is jerking-foward, not pulling smoothly. It happens a little when cold, but seems to be more noticeable when it's warmed up. At highway speeds it seems to go away, or at least be a little less shaky. It also idles rougher than I ever remember.
Since this has happened I've googled the hell out of the issue and visited this forum for answers. Here's what I've done so far:
All new plugs and wires, cleaned the MAF, put in a new PCV valve, replaced fuel filter, replaced the transmission mount, and yesterday cleaned out the IAC. Each helped a little but didn't fix the problem. The truck idles a lot quieter since cleaning the IAC (which was pretty dirty), but still idles rough at ~800rpm at rest. I've checked all of the vacuum lines (and elbows) I can think of and couldn't find any cracks. Also, the vacuum ball is still in one piece, and I haven't modified anything on the truck.
It was after cleaning the IAC that I noticed my truck making a hissing noise right when the throttle is pushed in that I hadn't noticed before. It seems to be coming from behind the throttle body area I think. I made a video of this that can be watched here: http://www.youtube.com/watch?v=-Vp_gHKPS_U
At this point I'm thinking it's got to be a vacuum leak SOMEWHERE in this thing, but I'm not 100% where yet. When I get a little more confident and have a fire extinguisher handy, I'm thinkin of trying the "carb cleaner test" around the engine to find any hidden leaks that way.
So, from this short novel I've written here, does anyone have any other suggestions for anything that I can try that I'm obviously overlooking here?
I'd appreciate it!
Edit:
Also, one thing I forgot to add. Before I cleaned the IAC, I "tested" it but unplugging it while the engine was idling. I'd read on here that it was one way to test if it was working. Some said if it was working, the idle would get REALLY bad, but in my case, the engine shut off entirely and wouldn't start without the IAC plugged in. Dunno if this is relevant or not, but just thought I'd throw it on here.
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