1995 f150 inline six
almost 200,000 miles
just replaced the head gasket
did valve job
replaced oil pump
cleaned thottle body
replaced pvc valve
i'm sure i'm forgeting some stuff.

a little background on the problem:
after we bought the truck we started to change the oil only to find that there was none showing on the dipstick. i know.
we changed the filter and added oil. upon starting the first time after the oil change, tons of white smoke poured from the tail pipe and it began to run rough, also lit "check engine" light.
After we took the engine apart we found that the old oil was gelled up very badly. packed into the valve covers and various other places.
evidently the previous owner was not big on changing oil. we figured that the gel in the engine was not showing on the dipstick and therefore when we added the new oil it was considerably over-filled.
at that point we cleaned everything, did the maintenance listed above, and put it back together. when we fired it up, it ran a little choppy but no smoke.
after a few minutes the smoke was pouring out of the tailpipe again and "check engine" light.
I checked the codes and found the MAP sensor was failing as well as a few other problems, including engine idle control. After figuring out we left the MAP sensor unplugged, and plugging it back in, it ran a little choopy but no smoke. we started it a few times after that, let it warm up, and it ran fine.
I just took it out for a test drive and it ran good. i gave it some gas from a dead stop. it spun the tires, but the smoke from the tailpipe came back.
I parked it for about an hour, cranked it over, and no smoke, no check engine light, and it was idleing better.
I drove it later, after about 10 minutes had the same smoke coming out, not as bad now though.

Any ideas or similar issues?
Thanks!

 

Hmm, where's that crystal balljoint?

Is it the correct dipstick? Did you fill by what the specs say for number of quarts, or till the dipstick said full?

Maybe some oil channels are still plugged. If a delivery line, it might increase pressure and make oil shoot where it wouldn't normally end up in quantity. Or a plugged return line might let it puddle up and enter via the valves.

No new bearings anywhere, just a clean up? It's hard to say what might happen. I suspect oil pump pipe or oil feeds for the bearings are also as plugged as everything else was. Maybe you got in there and fixed that already.

When you hit the throttle, all the little unseen blockages might cause the excess oil to travel another path with greater force. And/or bearings are shot, rings are bad... Did you do a compression check?

Maybe this was something else mixed with the oil, gas or antifreeze/water, left to time and some chemical experiment, thus the gel.

-Smoky

 

White smoke if often a sign of water/coolant leaking into the combustion chamber. Possible head gasket problem. You could try adding one dose of stop leak, just to see if the amount of white smoke is temporarily or substantially reduced. If the white smoke stops, you know where the problem came from. don't try as permanent fix.

The gummed up oil residue you left behind could also be that the PCV valve and associated circuit is not working correctly. A properly working PCV actually helps keep the oil and inside of engine clean by continuously removing combustion and other nasty vapors from inside the block. Nasty vapors can form nastly sludge over time.

 

Hi Smoky,

I believe it is the correct dipstick, but if I can find another straight six i'll compare them.
After we put everything back together we added 5 quarts and it showed full.
I think your right about the blocked channels. The manual says to add 6 quarts with a new filter (which was the case), so theres clearly something off there.
We cleaned the oil pump pipe, but we haven't been in the crank case yet.
No new rings or bearings. No compression test yet either.
Another symptom that happens intermittently is a lifter tap. It happens at the same time as the smoke, which kinda leads me to believe that it's gelled up and sticking occasionally.
My dad talked to a mechanic at his work today that suggested we drain the oil, add 5 quarts of automatic transmission fluid, let it run for an hour, then change with regular motor oil.
He also suggested running the truck with a quart of ATF added to the regular motor oil all the time.
My dads pretty confident in this approach, so we will probably be testing it friday.
I'll post the results.

Thank you very much for the suggestions.

 

Hi Icewagon,

We replaced the head gasket about a week ago. Though the stop leak is a good idea i'll try if the ATF doesn't work. I will also check the PCV valves condition.

Thanks!

 

Yeah, maybe a lifter is sticking or sluggish, leaving a valve open. Valve seals probably got replaced with the valve job, but the smoke showing up in concert with the ticking is a sign for sure. One plug may be fouling as another symptom that could point to the cylinder giving the problems.

-Smoky

 

your first post said you replaced oil pump, did you use a new pickup/oil screen?

how did you do this without opening crankcase?

 

Is the truck an automatic or stick? I had a van one time that had a modulator valve go bad and it was allowing the trans fuild to be sucked out of the vacuum line and into the engine causing it to have white smoke come out the exhaust.