Need Help. 87 Custom White smoke

[tmedic]

I have a 87 Custom Deluxe. It was doing great until I towed a small trailer. When I was backing the trailer white smoke started coming out both exhaust pipes. Oil level is fine. Truck has a 305 TBI. The first time it did this I blew it off. The second it was a little more smoke and it blew out a big puff when I put the truck in drive but then cleared up. I also noticed a 5 mpg drop in my fuel economy at the same time. Any idea's would be appreciated.

[Unofficial]

Sounds like blow by. That's what happened to me with my 350 tbi. I was blowing oil out of the valve covers and eventually the exhaust started smoking pretty bad. How old is the engine?

[tmedic]

Original engine. I did about 3 months ago switch to a true duel exhaust. If that makes any diff.

[Grim 82]

Did you check your coolant level/condition?

[Unofficial]

Well it might be due for an overhaul if it gets much worse... My 305 tbi did that but only on start-up. I've since put in a 350 tbi that I blew the rings in which is getting replaced as of now.

[tmedic]

Engine coolant levels and condition are good. Oil levels and condition are good too. By overhaul what do you mean? I'm guessing more than the typical fluide change and plug/wire change.

[jaredts]

Try removing the pcv valve and the pcv vent hose from the valve covers and start it up.  If a significant amount of smoke comes out of the valve covers then its worn rings.  Of course a cylinder leakdown test would be the best thing.

[tmedic]

Just tried that. Smoke did come out   about half the amount you'd get from blowing out a match.

[Captkaos]

Sounds like the seals in the heads are on their way out.  Did you do a leakdown test?

[tmedic]

No I don't know what a leak down test is.