1997 F150 4x4 4.6

About a year ago within weeks of each other, the truck started losing power, the check engine light came on, and the engine started to lose oil...sometimes a quart a month.

Please offer any insight cause I have no idea...neither does the 3 different mechanics that have looked at it.


Engine issue:

I have changed out the fuel filter, the plugs and and the wires. The truck seem to gain some power back, but only for a few months. A compression test was done and all 8 cylinders are show good compression. The truck has lost alot of power in the low end....ever on a wet road, it is very difficult to spin tires. The muffler and the cat converter have been checked....they are ok. The truck is at best running at 40-60% power from what is use too...also it is burning 2 to 3 times as much gas.

Check Engine Light:

Check engine light is still on after a year...it did turn off for 3 weeks after the plugs were changed. It does turn off for maybe a day if I put premium gas in the tank.

Oil:

Like I said, the truck is losing oil...maybe a quart a month...more or less depending on how much the truck is driven. Cylinder compression is ok, no blue smoke in the exhaust, no oil leaks on the engine, no oil in the antifreeze. Honestly, I have no idea where it is going.

Any ideas, suggestions what this could be?

 

did you ever think to find out what code set the cel off???

 

a truck that old is gonna burn oil. you might want to clean out your throttle body and check your air filter. could also be a fuel filter might want to replace that

 

What's the code ?? go get it read , it's free..

 

Go get your code(s) read. Autozone does it free. That will more than likely be the answer to your problem.

I also have a 98 4.6. It burns exactly 1 quart a month. It also will burn more, if, I go on a long trip. You have to expect an 11 year old vehicle to burn a bit. Now if it were 1 quart every week to 2 weeks, start to worry.

May I ask, What plugs were used when you replaced them?

 

O2 sensors??

 

My magic 8 ball says bad valve seals and the check engine light is a misfire code.

 

Yea torkum , I remember that site's vid you posted last week mentioned something about seats in the 4six's - tolerances had a broader margins from the factory. On the rebuild, they replace all and tighten the gap. I have a feeling that's why Ford says burning as much oil as some of these motors do -is normal.

Anyway, How many miles are on this 4six and yea, what plugs did you use ..

Get that code read dude..

 

So I did not mention it about, but I had gone to a dealership twice to have the check engine code ran...they claimed no code came back and it was probally a malfunction with the CE light.

Based off you guys, I did run up to Autozone and had them check it and sure enough, its showing O2 sensor.....thanks guys!

 

Did you actually get the code number?

 

Info is showing

PO141 Heated Oxygen Sensor Bank 1 Sensor 2

Searching through the forum now to get more info......so far I know its aftercat.....anyone have any ideas how difficult it is to change out?

 

Its easier to change the after cat sensors but I would be worried your cat is bad. Those rarely fail when you trip the code it usually means the cat is bad.

 

That might be where your power loss is from, the ole cat is plugged up.

 

Yea , that's a first for that code..I can't remember how to test your cats -damn I must be getting old

Well, here's a primitive way , the plugged side will be hot as hell, maybe even glowing in the dark lol. See if there's a noticeable heat difference between your cats -Bank1 vrs. Bank2..

How many miles do you have on her?

 

yep clogged cat