Got a bad case of blow by (I6 300).....

I've got a minor amount of oil coming out of dipstick and oil/white smoke out of the breather. Enough smoke to be pulled over by the police. I know that the true fix for this is a rebuild.

I did a compression test and came up with these readings starting from the cylinder closest to the radiator:

180,120,120,90,90,80. (PSI)

This fails the lowest shouldn't be 75% of the max criteria.

I have a temp fix set up by routing a piece of hose from the oil breather into a plastic oil container to catch the oil and then another piece from the top of the oil container into the side of the air filter housing to suck the smoke back in.

I can't tell if I've lost any power since before this started. And besides the smoke and the oil loss the truck seems to run the same. My question is can anyone chime in on how long their engine has ran with with blow by?

 

Was that a typo, or do you really have one cylinder sitting at 180 PSI? The rule of thumb is all cylinders should be 10% of one another.

I have a 351W in my old college beater (1977 LTD). It had awful blow-by, so bad that it would fill the air cleaner with oil and soak the breather filter. Instead of rebuilding an engine in a car that I paid $700 for, I opted to go a similar route as you. I disconnected the hose that runs from the valve cover grommet to the air cleaner, and ran a length of heater hose from the valve cover grommet down to the ground, and zip-tied it to the frame rail. Blow-by problems "solved."

Your question was what effect will this have on the engine - the sad news is that all of those fumes and smoke that are coming out of your breather hose are soaking into your oil as well. Unfortunately, once the rings are worn past a certain point, the fumes become more than a healthy PCV system can handle. As such, you should change your oil more than you used to - maybe switch to 2K mile intervals, or even shorter. My LTD has been like this for years - it's not great for the motor, but the car is a beater anyway.

Your method is actually better than mine because the fumes do get sucked back into the motor whereas mine just go out to the atmosphere (not great for the environment). Maybe I should try your way?

 

Yep, Fords standard is only 10% difference, not 25%. I wonder why it gets worse as you go toward the rear. Do you know the maintenance history?

 

Nope it really was 180. The plug in this cylinder looks different than the others, it almost looks like it is not firing.

We have owned the truck for about 6 years and have not done much besides change plugs/wires/oil the routine stuff.

I had to route the vapor back into the air cleaner because the smoke was really bad.

 

Every severely worn I-6 I've ever worked on or torn down has always had progressive wear from #1-#6, usually 4, 5, and 6 being more worn. Not sure if it's by design or what.

FWIW, I would personally figure out how much wear is on the cylinder walls and at least re-ring this engine, if not do a full overhaul with oversize pistons - OR, get a rebuilt short block and swap 'em and call it a day.