I noticed today that my blow-by smelled kind of burnt...and when I took off the oil-fill cap in the valve cover there was a haze coming out. This seems to be new since I have pulled the cap off before with no mist. The truck has well over 100,000 miles on it. I have always expected a little blow-by but the mist out the valve/oil fill cap has me worried. Should I be? Now I feel like I can hear the valvetrain squeaking, but it is probably just my paranoia.

What should I inspect? I have heard a vacuum line failure can add airpressure to the pan, but all of my vacuum operated accessories work.

Would it be a valve issue, or rings?

Oil looks and smells fine/normal.

Truck still rips along just fine.
Thanks.

 

Was the motor warmed up?

 

Yeah...about 45min to 1 hour of driving on the highway...normal temps.

 

ignore it,but you might want to check the blowby tube and bottle (if you still have one) to see if it's plugged

 

Might plug off the vacaum pump to make sure a small leak is not your issue.

 

How does the vacuum pump create crankcase pressure?

 

The "exhaust" of the vac pump goes into the crankcase, so if you have a vac leak it will always suck air into the engine and this will have to come out through the blowby tube or the oil fill cap if it's open.

HTH

AlpineRAM

 

Ok thanks...my second question was whether or not I should just expect blow by and not worry about it. So Johnh...I will not worry now-thanks. I will also look for leaks in the vacuum system. The blow-by bottle is long gone and the tube is clear so I will keep an eye on anything changing but I will now remain calm. In fact...I am re-doing the crank-case vent with PVC the weekend, so I'll know for sure if the hose I had used was pinched.

Thanks Guys!
-Geoff