Weirdness With My BJ7

Earlier this week, I noticed a long drip running down my driveway right after I had parked the car in the garage. The drip was heaviest as the car got close to the garage and was heading downhill and then tapered off to nothing just as the car entered the flat garage. A picture of that drip will be attached. It's still very visible despite many rains so it's not water or antifreeze but is petroleum-based. It's not brake/clutch fluid as that reservoir is full to the top. And it's not radiator runoff as it wouldn't still be a stain in the asphalt after being rained on many times in the past 5 or so days. This shows the drip in the driveway: https://www.youtube.com/watch?v=0DnMnBvhV84&feature=youtu.be
As you can see, it gets heavier as the car approaches the garage on the incline of the driveway and then peters out just as the car enters the garage.

I checked the oil and was down a quart so I added oil. I checked the radiator and added about a quart of antifreeze. I pulled the car out this morning and examined the garage floor. There was no evidence of any leaks on the left side of the car. There are plenty of puddles in the center and right side, though. Typical for the age of the car.

I drove it to the local mechanic and got it on the lift this AM. The engine and transmission and differential all had the usual wetness of slow leaks which were wiped off and the engine was idling for a good 20 minutes while on the lift. No leaks or drips occurred. However, we lowered the car to the ground and noticed white smoke coming out of the rear carburetor's air filter (from the back part of the filter nearest the firewall). You can view a short video of this smoking air filter here: https://www.youtube.com/watch?v=gcsOP_en12M&feature=youtu.be

We also noticed that the breather pipe was loose at the carburetor so we clamped it. Someone suggested a worn rocker shaft allowing too much oil into top, being sucked into the breather pipe by the carb.

Could the drip line in the driveway have been caused by fuel that the rear carburetor dumped due to a problem with the carburetor? Or oil being sucked into the carb and dripping onto the ground? All advice will be most appreciated. Thanks!

UPDATE: I found this online which probably explains what needs to be done. Please comment if you disagree and have a better diagnosis. "The Healey rocker shaft is located under the valve cover on top of the engine and can be a readily remedied source of trouble. The function of the rocker shaft is to hold the rockers in place on the valve train and to keep the valve timing intact. Oil is fed through the oil feed pipe into the shaft and along each rocker to oil the top of the engine and return. There is tremendous pressure here and what may occur is simply: Rockers turning on the shaft sometimes score it and the resulting gap allows oil in be forced out of the rockers and through the breather pipes to the rear carburetor. Therefore you are fouling your carburetors, mixing oil and gas in the engine, apparently using an excess of oil which your local repair shop will tell you is caused by everything but a rocker shaft."

You can rule out gas by smelling it--yeah, your neighbors will think you're nuts (they probably do anyway since you drive an old British sports car)--and, for the most part, modern fuel formulations don't leave a stain. White smoke usually indicates brake fluid burning, but apparently you're not burning any. The smoke out of the rear carb could be blue-sh; so, oil.

That 'drip line' is typical of coolant coming out of the overflow pipe.

Bob_Spidell said:

That 'drip line' is typical of coolant coming out of the overflow pipe.

Click to expand...

I poured pure antifreeze next to the drip line a few days ago to see if it would last and be visible after rain but it's gone & the drip line is still very visible, so I doubt it's coolant.

Assuming you have a very worn rocker shaft, it will spew oil out of the breather pipe into the rear carb air filter. However, all of that oil will not get sucked in and get burned up. Instead, it will load up your rear air fliter. I suspect that when you made the climb up your driveway, some of that trapped oil escaped.

Given the air filters are round, I reckon oil can escape at pretty much any angle.

Norm Nock in his book says to run the engine with the rocker cover off. Oil from a worn rocker will geyser up; an unworn rocker will gently flow the oil out.

Fuel will evaporate somewhat quickly. Oil will leave a stain that lasts months. I had a leak that looked just like that. It turned out to be a leak in the oil line to the lower part of the engine and easily replaced and cheap fix. I was originally frightened it was a crack in the block. The funny thing is that it the oil line "looked" perfect.