Hey guys. Its been awhile since I been on here. I have a 1998 f150 4x4 with a 4.6 triton vin #w and only 150,000 miles but its smoking. On first start up everything is good to go but when the engine reaches operating tempetures it will smoke.

It does not smoke all the time, just on takeoff. Such as after taking off after sitting at a red light it will puff a cloud of smoke from both sides of the engine. The engine is smoking blue so I know its oil its burning.

I pulled the valve covers off last week and the engine is clean, no sluge or gum.

What do you guys think?

Power is good, runs good, and has good compression. I just have no idea why its smoking.

 

start simple...change your PCV....with a motorcraft unit...often times a cheeper aftermarket ones do not function well. price difference is minimal.

Are you finding the need to add oil more often?....if so ...how much and within how many miles?

what were the compression numbers?

 

I can remember the compression... I'll have to run another test. And its burning about 1 quart ever 1500 miles. I have replaced the PCV but not with a motorcraft. I bought a MasterPro from Orielly autoparts.

I did find the boots for the breather on the drivers side going to the throttle body where cracked so I replaced them. But its still smoking. I was running 5w-30 oil (stock) but stepped up to a 10w-30 and found no difference. And im running Motorcraft oil and filter.

It runs too good for the engine to be shot, but I guess that could be a option too.

I have never dealt with these newer style modular engines. Just the old school Windsor engines.

 

Valve stem seals?

The first few years of the 4.6L in the early 90's in cars did exactly as you described with enough mileage. Many smoked well before 100k miles. Used to see Crown Vics, Town cars and MGM's smoking away from a stoplight all the time.

Over at CrownVic.net they used to pass around a valve depressor tool to make changeout of the seals doable.

Ford changed either the material or the seal design, as the later years did not have the problem. Nonetheless, you could stop in over at CrownVic.net and see if anybody is still around that had it, to get a better description.

 

Think i'd still change the PCV...just for piece of mind, if nothing else.

yah, valve stem seals could be the culpit too.

Do you have the plastic composite intake, or the alum intake manifold?
if plastic ...might have a hairline crack in it? I think I read of others having that trouble?

might be worth your trouble to remove the throttle body housing ( above the intake manifold)....there is a couple of EGR ports in there that can get clogged up and give some troubles too. Then it is real easy to clean the IAC too while it is off.

 

I have the aluminum intake. And the throttle body is oily looking. If that helps? Can a egr valve cause theae problems?

Also tomorrow ill post a video of.how.the engine is smoking. Im thinking my oil ring might be shot.

 

If the inside of the throttle body is looking oily/all carboned up ...definitely clean it...not a hard job...couple of hours. clean with carb cleaner

Maybe the Oil rings are just gummy...do you short trip this a lot?
Meaning..... drive less then 5 miles and shut it off...thereby, never really getting the oil and engine block fully up to temp...the coolant may say it is...but the rest is barely getting there.

do you have aftermarket air filter that requires oiling?

 

I do short trips. But i do take longer trips too. But not very often. And also i have a K&N drop in filter.

I didnt have time to do a video today but itll be tomorrow. I know when the engine reaches operating temp if i rev the engine up it doesnt smoke. But on deacceration of the rpms itll smoke. Almost like its.sucking oil by the rings.

 

I also just thought about a 4.6 4v swap.

 

can be done...but you would need the wiring harness and ECM from the donor too. ECM might not but you're old one would need to be reflashed...If I understand correctly.

If your going to consider a 4v swap...you might be happier with a 5.4 4v from a Navigator. & then grab the harness, sensors and ECM & tranny if you can.

Back to you current situation....Often times the K&N gets over oiled/serviced....that oil then migrates through intake plumbing...making the sensors along the way ...unhappy to say the least.

so clean the MAF sensor...with MAF sensor safe cleaning spray. clean the entire intake plumbing...including the throttle body & housing...good carb cleaner works well. Noting the condition of the EGR ports inside the throttle body housing.

I would still change the PCV with a MC one too.

 

My 97 4.6 does exactly what yours is doing. Keep us posted if you figure out the problem. I've also been suspecting valve seals. I replaced my PCV valve with no luck, and replaced my IAC valve (it was bad anyway) It seemed to me like the problem got better when I replaced the IAC valve, but it might also be in my head.

 

I think my IAC might be going bad because the truck will surge power sometimes, and every once in a while almost cut off before reving up and then idling level.

Also I don't know if it'll make a difference but the two rear cats are missing too. I'm just not sure why it is smoking.

Here is the video, what do you guys thing the problem could be?

http://<embed width="600" height="36...a6ea4315.mp4">

 

DSCF6577_zpsa6ea4315.mp4 Video by 89F1504x4 | Photobucket

 

This weekend I plan to go to FoMoCo and get a PVC valve. But I think my idle air control valve is going bad too, sometimes the engine surges. And on the next oil change I'm going to go to a full synthetic oil, I really don't want to tear down this engine and replace the valve seals.

 

yeah she's getting kinda belchy ...how much is the consumption rate?

If it surges at Idle...then the IAC is highly suspect...the new PCV certainly couldn't hurt...not gonna guaranty it will cure it. But it will rule it out as the cause.

kinda curious what kind of vacuum pressure the engine is generating? should be somewhere 20psi
found this useful> How to Use and Interpret a Vacuum Gauge