Hey guys. Been about a year since I've been on the forum, and that was because of my last problem. Which you guys nailed. I had a wheel bearing issue. Then eventually rotors needed replaced.

So I know you guys can point out, or at least give me a better idea of whats wrong, from my description.

My current issue is that the car shutters while sitting at idle. Every other second, the car does this very minor shake. You can hear the engine drop RPM's when that happens. My guess is its a spark plug issue. It is about 75k on original ones.

Now, tell me if this is apart of the same issue. The car sometimes jumps off the line with very minor amount of pressure applied to the gas. Or sometimes it doesn't go anywhere and needs more pressure applied. Then when coasting from start up, before the engine gets warmed up, the engine blurbs forward. Its as if I press the gas, let up, press the gas, let up, etc. It usually goes away after I drive 100 yards or so.

But jumping off the line seems to happen about 1/2 of my stops on my way to and from work. I feel like an idiot when the car does it at a stop light. I keep thinking that the other drivers around me are figuring I'm trying to show off.

And the final thing that I've noticed its been doing a little more lately, is when I'm cruising around 20-30, and it shifts down, sometimes its a hard down shift. I can feel the wheel almost skid across the ground. Its not a graceful transaction. Very abrupt shift. It's an automatic.

The downshift thing has actually been happening for about a year now. The other things have been happening within the year.

Thanks for taking the time to read this. And hope I can get a better idea of what needs to be done, and how much its going to cost me.

 

May have solved part of the problem. Like a dummy, I haven't kept track of how often I've cleaned the air filter on my CAI. I showed what was happening to a co-worker. I popped the hood, and revved the engine. He pointed out that the air filter sounded like it was having a hard time sucking in air. And sure enough, it was a new sound I hadn't heard before.

So tonight will be pulling off the filter to see if that fixes it, and giving it a good cleaning.

 

At 75k if you haven't, it's time to clean the throttle body plate area and IAC (idle air control). The spark plugs should also be changed with new plug boots as well.

 

Yeah, nothings really been cleaned out. Will start to do some research on how to do this.

Cleaned the filter out last night. The ride seems to be a bit smoother. But won't really be able to tell until I take it out a few more times. But apparently I've either forgotten about the CAI noise, or have never noticed it. Because after taking the filter off. I started the car up to see if that fixed the idle issue. And still made the sucking noise during rev.

Any brand/place that you'd recommend for spark plugs and boots? Thought I'd stay away from motorcraft spark plugs for the two piece reason. Looked at Champion and seems like it has some fairly un-favorable reviews.

 

First steps...and easy to do...is to clean the MAF ( mass airflow sensor ) and the throttle body. If your air filter was having trouble breathing, I'd bet your MAF is dirty as well. Make sure you use a "coating safe" throttle body cleaner. CRC makes both a great "coating safe" throttle body cleaner and MAF cleaner. When cleaning the MAF, make sure you don't touch any of the part of it that fits internally into the air tube...you'll just contaminate it again. Clean both of these and I bet you'll see a VAST improvement in how it runs, performs and response.

 

I myself would use Motorcraft plugs as I prefer oem parts for design purpose applications; like spark plugs, thermostats, and oil filters. A wiper blade I could care less.

The plug boots I would buy may be NGK as they come with boot and new coil spring for the same price as Ford's boot only and buy the spring separate. At least that's what it is where I live.

 

So the issue was probably the alternator. How long can you start to see symptoms before it dies?

Yesterday after work I was sitting at a stop light and it DRASTICALLY started dropping RPMS. The battery gauge was dropping and rising too. At that point I figured it was the alternator. And then it died. While I was still sitting at the light.

Had it towed, and the Ford dealer just called to say that my total fee is going to be $800. Seems a pretty high to me. But I really don't have the ability to replace it myself.

 

You took it to a Ford dealer and got the benefits of oem parts, I assume, which comes at a high price. That kind of mileage the alt's brushes and slip rings may have been worn giving you intermittent charging. How old is the battery? Did they change it too? A bad cell can make the alt work harder. I've had to change the battery on my 05 once already with only 47k. It had 2 bad cells. I do have the factory alarm and shaker 1000 and the car sits for extended periods though.

 

Boy. Just want to get this thing fixed and back to normal. They replaced the alternator and recharged he battery. They said the battery is good and was holding a charge. The battery was replaced back in 2008 I believe.

But after picking up the car, the car was still fluctuating between 400-1200 RPMs at idle.

Suppose the next step is to clean the MAF and throttle body, and see if that fixes the problem.

 

Just wanted to say Thanks! to you Lime GT and Sabre.

Just cleaned the MAF sensor and throttle body. And boy was the drive to Autozone to pick up the cleaner painful. It was really acting up.

But did the clean of both those things. And everything apears to be normal. Just took the car around the block. But in that distance from my trip to Autozone, it was already doing bad things. After the clean, the car was nice and smooth.

Was a little worried for a couple seconds though. The car turned over, but wouldn't fire. And then it coughed, and fired up. Figured it was left over cleaner from the throttle body.

But thanks again! Love the help this forum gives.

 

Glad to help and glad these ideas have seemed to help your problem. If the car has been good and then starts running rough, the MAF and throttle body are usually the first 2 places to start looking. When you know they are OK...then go on from there with diagnosing and resolving any problems. Luckily, they are pretty easy to do.

 

Good to here you got her running smooth.

 

I might have to try cleaning mine out too. Mine's at 87,000k and I've noticed some similar symptoms. My idle is just fine, but I've noticed that sort of delayed reaction sometimes when you apply the gas.

 

My MAF and throttle body were cleaned at 85k. She drove like new after that. The change was truly dramatic.

 

Yeah, its pretty amazing what such a simple thing can do, to make your car run better.

Been running it for the past few days now, and I'm 99% sure that was the main issue, other than my alternator dieing. No more awkward accelerations off the line at a stop light. Its all nice and smooth.

Oh, and the other thing I noticed was that I have a slight incline on my driveway. Before cleaning the MAF and TB, if I stopped to wait for the garage door to open, my car would roll backwards after letting off the brake. (Automatic.) After cleaning, it will now idle forward without any gas applied.

Now when I get my motorcycle back from the shop, I'm going to attempt replacing the plugs. That way I can take my time, and not have to worry about doing it all in one day. I can let the penetrating oil do its job.