Instant smoke screen?

[Speedwagon]

Driving down the road, with this '87 2.3 I just bought, everything seemed fine. Then, suddenly, I had an instant smoke screen behind me. The kind that makes it hard to see for everyone behind me. Stopped, looked at things, and all seemed ok. Got back on the road, and suddenly the smoke stopped.

So... wtf is up with that?

 

[Derek The Great]

I'm not sure but mine did something simlar to that a while back. I got outta work one day and fired it up, and it burned oil for like four seconds straight, making a bigger cloud that my 305 GM does. My guess for the problem would be the same problem the 305 has, valve guide issues. After that one day though, it hasn't burned oil since.

 

[Mark_88]

If it's fuel injected, sometimes oil from the top breather gets into the intake...if it happens to get sucked into the intake you get instant smoke...thick, black, smoke that should only last until the oil is burned off...

check the top vent hose and see where it goes (carbed units go straight into the breather and FI goes into the TB) and take it off and check for oil drips...

You may want to clean out your PCV top and bottom...replace the PCV valve if you haven't done so in a while...

if the PCV is not working proplerly your engine is not venting properly and it could lead to other problems later...like oil being spewed out of the dipstick...

However, if the PVC is OK you may have rings or valves that are going south on you...

 

[Speedwagon]

If it's fuel injected, sometimes oil from the top breather gets into the intake...if it happens to get sucked into the intake you get instant smoke...thick, black, smoke that should only last until the oil is burned off...

check the top vent hose and see where it goes (carbed units go straight into the breather and FI goes into the TB) and take it off and check for oil drips...

You may want to clean out your PCV top and bottom...replace the PCV valve if you haven't done so in a while...

if the PCV is not working proplerly your engine is not venting properly and it could lead to other problems later...like oil being spewed out of the dipstick...

However, if the PVC is OK you may have rings or valves that are going south on you...

I was wondering about crankcase pressure on it, if that might have caused it. I just bought the truck, so I have to go through a tuneup on it still.

 

[Mark_88]

Could be all it is...I just noticed your engine is listed as a 3.0...they are slightly different than the 2.3 so you might want to check with people in that forum...unless you do have the 2.3 engine...

Your engine would be FI either way with a 92 so there is probably a tube runing into your TB from one or both valve covers...

 

[Speedwagon]

So after having the truck sit for about a month in the garage...

I fired it up last week, and did get some smoke from the exhaust. Once it was burned off, haven't seen anymore since. But I've only been driving around town with it as of late, and haven't taken it on a trail in probably 2 months now.

Just did a compression check on it, and I got 140/140/130/125. Nothing extremely low, and 1&2 seem to be good and strong. The PCV seems to be working fine, and sometimes the bottom hose of the PCV falls off, so it's not an issue of the crankcase getting too much pressure. I need to get a hose clamp on the bottom tube, because a ziptie didn't hold it in place(it helped, but not enough).

And yes, the tube that comes off the top of the valve cover does have oil in it, so it seems that the oil gets pushed out that tube, and into the intake. This also results in a half oil soaked air filter, with oil dripping out of the airbox.

So what's my next step? Valve stem seals? They are likely very old, and possible gone(since it did smoke on startup, after sitting for about a month).

 

[Mark_88]

You're compression is within 10% on the last two so I wouldn't worry about that too much...if there hasn't been any smoke lately then it was probably just being pushed into the intake and you got some going into the combustion mix...

If you cleaned out the tubes and replaced the PCV I'd say just run it for a while and check to see if oil is building up in the tube quickly...and if you haven't already done so change the air filter since that can hinder performance considerably...

 

[Speedwagon]

You're compression is within 10% on the last two so I wouldn't worry about that too much...if there hasn't been any smoke lately then it was probably just being pushed into the intake and you got some going into the combustion mix...

If you cleaned out the tubes and replaced the PCV I'd say just run it for a while and check to see if oil is building up in the tube quickly...and if you haven't already done so change the air filter since that can hinder performance considerably...

No, you misunderstood me. There hasn't been any smoke on startup lately, which is completely seperate from the smoke screen it makes. At the time I wrote that, I hadn't had the truck out anywhere that would cause it to make the smoke screen.

But I took it on the trail yesterday, and the smoke screen is still very prevalent.