ericarrendale

Hey all. I'm new to the forum. Not an expert mechanic by any means but I do what what my experience can handle. Bought an 03 f150 xl from a woman on craiglist. Rebuilt title, 188k miles and ran decent but had the CEL on. A week ago started idling rough, mostly when the motor reaches normal operating temps and I am in reverse or drive. Black smoke blows out the tailpipe and just smells bad when this happens also. There are no codes popping at this time. However when I first got it I was getting a p0172 and p0175 which i took care of when I replaced the upstream o2 on both banks. I took apart the aftermarket intake, the throttle body, intake plenum and cleaned, cleaned, cleaned all ports free of carbon now. EGR ports into the plenum were nearly clogged. Replaced gaskets on plenum, throtte body, IAC valve after cleaning, EGR after cleaning. Induced seafoam in through the brake booster hose. Changed motor oil, rear diff oil, tansfer case oil, flushed Tranny, coolant, power steering. thanks for teh help

jprevat

iTrader: (1)

A rough idle like that is making me think you have a vacuum leak somewhere. Check your pcv valve and make sure it is Motorcraft then follow where it attaches with a rubber elbow at the back of the intake and make sure it is in good shape.

The black smoke is beyond me. Sounds like over fueling or the result of an incomplete burn.

ericarrendale

Thats kinda what I was thinking. I pulled the plugs yesterday. They were fouled up and black. I cleaned em off and regapped them. They looked pretty new and the lady I bought the truck from said that she had them changed. I noticed that my oil level was lower and pretty dirty. It also smelled like there may be fuel in the oil as well. When I get a chance I m going to check the fuel pressure regulator. Could it be that maybe i have a blown gasket farther down in the intake? PCV valve and hose is good. I had checked that earlier on. What is that tube coming out of the driver side valve cover and should it have a strong vaccum? I pulled if off and it has a very very weak vaccum to it. oh yeah I pulled the injectors and cleaned those also.

jprevat

iTrader: (1)

When you pulled the plugs you didnt happen to notice if the were motorcraft did you? Fuel pressure regulator may be a good place to start. What oil are you running? One guy on here was using 10w30 and had a strong gas smell in his oil. After he changed to 5w20 everything went back to normal.

ericarrendale

they were bosch platinum plugs. Put mobil1 5w-20 when I changed the oil

jprevat

iTrader: (1)

I would be hard pressed not putting mc back in these trucks. They are very picky when it comes to plugs

ericarrendale

I don't think that's what my issue is though. I didn't know these trucks are fickle about plugs. I've never owed a truck before this one all small foreign cars

jprevat

iTrader: (1)

Yep. I have found that 4 things on these trucks need to stay oem. Plugs, oil filter, pcv valve, and iac.

ericarrendale

Nice to know. I appreciate the info

jprevat

iTrader: (1)

No problem. Ill check that hose for vacuum when I get off work.