White smoke from exhaust pipe.

So I got a white smoke problem. I first noticed it yesterday. When I first start my truck up white smoke billows out the tail pipe. Once it warms up it stops for a bit. If I am just driving on the highway no smoke. If I'm driving through town it tends to start smoke after I have been sitting at a stop light for a couple minutes. If I am sitting at a light it doesn't smoke until I accelerate, then when I take off, enough smoke comes out to smoke out an intersection. I'm thinking possible blown head gasket. There are no other symptoms, besides the smoke the truck runs fine, oil looks fine, fluid levels are fine. Any ideas? Or anyone had the same problem?

 

White smoke is Anti-freeze.
Blue smoke is oil.

 

Forgot to mention its a 99 3.4l with 155,000 miles. Also never overheated and the smoke does not have a sweet smell to it.

 

Just pulled the air intake hose off to get to the spark plugs and noticed a lot of oil in the throttle body. Guessing that's the problem. Recently changed the valve cover gaskets and had to remove the throttle body to do so, but reused the throttle body gasket. So I'm thinking I may need to put a new throttle body gasket on it. Thoughts anyone?

 

Bunch of oil in the line going from the PCV valve to the throttle body. When I did the valve covers I changed the PCV valve, with one from the parts store. Guess I should have went to the dealer for and OEM one.

 

Keep an eye on the radiator fluid level. You MAY have a leaking head gasket or worse a cracked head. The only way to verify is to pull the plugs and look for a really clean plug or with one with caked on white deposits. If you find neither, it could be condensation build up in the exhaust. You could always do a compression and/or leak down test on each cylinder.

 

you will get oil from the PCV to the TB, the pressure forces out some and then it gets moved to the combustion chamber to get burned. now if you're talking a stream and not just "wet" then you have another issue.

 

You should be able to smell either burning oil or the sweet smell of anti freeze. Have another sniff.
The plugs should tell you something as well, oil burning will foul them with black crud.
Don

 

do a compression test, if you have ring blowby it adds pressure to the crankcase forcing airflow to increase carrying oil through the pcv into the TB.

sorry to say but it 100% sounds like engine rebuild time to me, but you could just keep driving it like it is.

pull all plugs and test compression on all cylinders one at a time, engine wear determines the pressures you get but good is around 150 psi but it can be as high as 175 psi or as low as 100 psi but whatever it reads, they should all be within 5-10 psi of each other.

then squirt oil in one and recheck then do the others one at a time and record the increase in compression from a good squirt or two of oil in each cylinder (just enough to coat the rings with oil).

if compression stays about the same, those rings are ok and if the cylinder has low compression its most likely do to the valves.

 

Yeah I'm talking like a large amount of oil in the throttle body, not just wet, but like its puddling up in there. Seems like it's coming from the PCV valve.

 

for now, doing the oil catch can mod will help with the smoke and oil puddling issues

 

The PCV is to remove crankcase pressure caused by piston ring blowby and to cause a vacuum in the crank case that assists keeping the oil in the engine by pulling it away from the seals. Want to see a mess? Remove that PCV and seal the crankcase. Every seal will be seeping oil.


If you have that much oil in the intake......You need to do a compression check.

 

Ok doing a compression test right now ill post some results when I'm finished.

 

So I did a compression test and all cylinders are at about 175psi + or - 5psi. So would that suggest its and issue with the valves then?

 

You have great compression numbers.
Hmm.

 

with those compression numbers it means the rings and valves are definitely sealing well so that's great news.

this means there is no reason you should be getting oil through the pcv valve and hose since low compression would be an indicator of blowby which you don't have based on those numbers.

for now cleaning the TB and intakes manifold and doing the catch can mod will cure your smoke issues but unless this is old buildup over time that just finally got sucked into the TB (and maybe even reached its way all the way through the intake to the valves) there is nothing I can think of as a reason for your symptoms.

those numbers are great news and signal there is nothing wrong with your engines rings or valves sealing.

 

The next thing to check is to do a pressure test on the radiator to test for coolant system leaks.

 

he already confirmed that the coolant levels are not changing

 

Well I tried a OEM PCV valve today. Drove it 10 miles, it still smoked occasionally. Pulled the air intake off and once again a ton of oil in the throttle body. I really don't under stand where else to oil could be coming from other than the PCV line. I guess I can try the oil catch can next, but judging from the amount of oil I'm seeing in the throttle body, the catch can will be full every few hundred miles.

 

You sure it's oil and not steering or brake fluid?