I have a 2001 f-150 V6 4.2 liter and after a few years of neglect, poor job market ect, I'm trying to understand my problems before taking it into the shop. I have a check engine light on and the codes are EGR insufficient flow, mixture to lean and a #5 misfire. I have changed the DPFE sensor, the EGR valve and replaced the spark plugs and wires. With each change being separate the light still stays on. I had an EGR port cleaning about 6 months ago but I'm not fully sure it was done correctly as I had Firestones do the work.

The plug change definitely improved the rough idling I was having but I've been hearing a metallic clicking or rattling when I accelerate. Its not every time but more often than not. I've bumped my oil to pure synthetic and to 5w40 but I'm not noticing a reduction as lifter noise came to mind. I read somewhere that clogged EGR ports may cause a metallic sound during acceleration. This sound occurs around 30 or 40 mph or both.

Also, I had the oil changed roughly 1200 miles ago and I checked it today and the oil was basically gone. It was just under the min line,and I see no oil stains where I park the truck daily. When the old plugs came out 2 of them were very fowled. I'm assuming my rings have gone bad? I also see no real change in exhaust color but I'll check it in the morning after my first start.

Any thoughts on the noise and a rough estimate on new rings done by a mechanic?

 

Oil "Leak": Id suggest doing a compression test. (Is there any coolent in the oil? )

When you said you changed the wires with the plugs, is it fair to assume that the coil packs were changed?

 

Thier is no coolent in the oil and today I made sure I was seeing no odd smoke coolers coming from the tail pipe. I changed the plugs (the 3 things on the left side and 3 things on the right of the engine) and the wires which connect them to the terminal thing. Sorry, I'm lacking in the proper terms for these parts. I did not change the terminal where all the wires meet.

I was able to throw the computer on the truck this morning and it appears I've cleared the egr problems but had a code which I wrote down but left in the truck while I'm at work. I think it was P0107 and P0147. So I'm thinking I'm down to a bad O2 sensor.

But which one and where is it!

The truck seems to be idling rough again. Do you think I should clean the throttle body now? My dad mentioned the sound I'm hearing may be some preignition sounds. He is recommending putting a quart of Mecron Transmission fluid in with the oil for about 10 days then changing the oil just to help clean out things. Any thoughts?



Thanks for the quick responce by the way.

 

A bad PCV valve will cause excess oil consumption and rough idle, use motorcraft brand

 

Cleaning the throttle body couldn't hurt, as far as adding transmission fluid to the engine oil, I'd be very hesitant, espically adding a full quart.

You may find it helpful to add an engine oil with a high amount of detergent. Although I'm an AMSOIL fan, Pennzoil Platnum is highly reccomended for internal cleansing, although for your particular situation I'd change your oil more frequently. It may also help to examine the contents of your oil filter, and if your feeling really adventorus, drop the oil pan....

As kbsupercrew mentioned, I'd also reccomend checking out your PCV valve.

 

If you lost a couple quarts of oil in 1200 miles, and its not on the ground... thats a problme. PCV valve is a good place to start.

 

OK, thanks for your help everyone. I'll research the valve and update my progress.

 

Update: 2/24/2012
OK, looks like the p0401 has been cleared now and the #5 miss fire was corrected with plug and wire change. I changed my MAF sensor yesterday and still waiting for another drive cycle to see if 0107 and 0147 come back.

I also may have found my engine oil leak. I was showing my step dad where the PCV was and I noticed something. So just below the coil pack and slightly in front of the PCV was oil on the engine. Enough to possible be the source of my problem. I wish I could post pictures but it's on the part of the engine were the plugs go into. The coil blocks my view but could this oil be from the PCV or from a bad seal?

Update: I checked the code again after writing the above. The same codes came back but this time it said the plenum bolts needed to be replaced. Seems like I'm one of those who will get to enjoy the check engine light for a long time!

MAF replacement seems to have solved the ping I was hearing. I just need to fix the oil leak and should be OK for a bit.