Engine: Oil Leak/Road Draft Tube

[Kato]

Finally had an opportunity to get my 62 GT up on a hoist to investigate where the excessive oil leak was coming from. I know it's not uncommon to have some oil leaks but I am getting large amounts leaking out of the road draft tube. There is slight seepage in other areas but the vast majority is coming out of the tube while driving and after shut down. I am adding a quart every 400 miles or so and there is no smoke or evidence of burning oil. I read once before of a screen filter held in by a cotter pin but I cannot find anything like that on this tube. The previous owner had the engine rebuilt about 4000 miles ago and installed a Lionel Stone intake and valley cover.

Other than a slightly rough idle the car runs very well, lots of power and no smoke or coking of the plugs. Any thoughts as to what would be causing so much oil to be pumped out the road draft tube? Would converting to a PCV system be a good idea? Can that be done with the LS intake and valley cover? The engine would be virtually leak free without this leak from what I saw underneath the car but this leak has left quite a trail of oil on the underside and on every road I have driven!

[rkapteyn]

Take it back to the guy that rebuilt the engine.

[JoeHall]

That much oil from the breather pipe, only 400 miles per quart, and minimal smoke indicate excess blowby past the rings. Could be, the builder used chrome rings and they have not yet seated, or something else having to do with the rings & pistons. Running thicker oil may help to reduce consumption and drip. Also, if it has synthetic oil, go back to dino oil for another 5000 miles or so.

Also, if the motor has been babied for the 4000(?) miles since rebuild, you might wanna run it like you stole it for a couple thousand miles. That might help the rings seat.

[jackb]

No red flags yet.....Did the builder install "chrome" rings ? If so, that could be your whole issue. If so, drive the ?+%# out of it. Other areas of dripping/"seepage" may require re-torqueing the pan seals. Don't expect perfection. If you haven't yet re torqued the heads-do so (some like it hot, others cold). Same with the valves (hot/cold). Drive the thing ! I'll assume your geography limits your driving....might be a big factor. I wouldn't change to a PCV system thinking I'd lower oil consumption and/or seepage....

[altair]

That is acting like your breather intake is plugged or otherwise restricted. Try removing it. I had this happen on two vehicles I owned and on a friend's.

[Kato]

Take it back to the guy that rebuilt the engine.

That much oil from the breather pipe, only 400 miles per quart, and minimal smoke indicate excess blowby past the rings. Could be, the builder used chrome rings and they have not yet seated, or something else having to do with the rings & pistons. Running thicker oil may help to reduce consumption and drip. Also, if it has synthetic oil, go back to dino oil for another 5000 miles or so.

Also, if the motor has been babied for the 4000(?) miles since rebuild, you might wanna run it like you stole it for a couple thousand miles. That might help the rings seat.

No red flags yet.....Did the builder install "chrome" rings ? If so, that could be your whole issue. If so, drive the ?+%# out of it. Other areas of dripping/"seepage" may require re-torqueing the pan seals. Don't expect perfection. If you haven't yet re torqued the heads-do so (some like it hot, others cold). Same with the valves (hot/cold). Drive the thing ! I'll assume your geography limits your driving....might be a big factor. I wouldn't change to a PCV system thinking I'd lower oil consumption and/or seepage....

Unfortunately is was rebuilt while owned by the previous owner who is in frail health and not able to assist me in figuring out whether chrome rings were installed and who did the build. I am running Brad Penn 20W50 oil as that is what the previous owner used. I have no doubt that the car was not driven often after the rebuild so I wouldn't be surprised if the seating hasn't taken place. I drove it 2000 miles this year and didn't hold back but nothing more than a 2 hour drive. It runs very well other than a bit of a rough idle and does not lack power or blow any smoke. I sure don't expect perfection, I know it will leak a little, but this seems excessive. It didn't seem to improve at all as I had the same thoughts that perhaps it just needed to be driven. It was most definitely driven more this year than it has in the past many years!

[Kato]

That is acting like your breather intake is plugged or otherwise restricted. Try removing it. I had this happen on two vehicles I owned and on a friend's.

I misunderstood this originally. I will definitely check the breather cap. Thanks

[karterfred88]

Two things, possible the breather cap is plugged as in #5, and you may be overfilling the engine oil. Drain the oil, measure amount put in, don't depend on the dipstick. Does your car have the bypass filter hooked up and done correctly. Besides too much blowby, if the crankcase oil level gets too high, the crank whips the oil into a frenzy overloading the lifter area and then blowing it out the draft tube. Rather than putting that quart in, next time, wipe the excess off the draft tube, and carefully monitor the level on the dipstick. see if it slows down the loss considerably or not. If it all but stops using oil at the add a quart level, perhaps you are overfilling it and the dipstick is wrong. Just a possibility.

[StudeRich]

I think the MAJOR contributor to this Oil Coming out ot the Breather Tube is that Aftermarket Lifter Cover.

I would bet money that those POC Lifter Covers are NOT baffled like the Factory ones are.

[345 DeSoto]

What HE said^^^^^^^^^^^^.

[r1lark]

I would bet money that those POC Lifter Covers are NOT baffled like the Factory ones are.

Hmmm......StudeRich, what do you mean by "POC"? Only thing I could think of is Polished Or Chromed.

Seriously, you bring up a good point Rich; I always wondered if those fancy covers worked ok without the baffle.

[Kato]

I think the MAJOR contributor to this Oil Coming out ot the Breather Tube is that Aftermarket Lifter Cover.

I would bet money that those POC Lifter Covers are NOT baffled like the Factory ones are.

What HE said^^^^^^^^^^^^.

Hmmm......StudeRich, what do you mean by "POC"? Only thing I could think of is Polished Or Chromed.

Seriously, you bring up a good point Rich; I always wondered if those fancy covers worked ok without the baffle.

Very interesting you should suggest this because I wondered about this very thing in that there must be something that keeps the oil from flowing out the tube, ie baffles! I'm really not sure the reason it was installed in the first place at it is barely visible and brutal to keep clean! I'm planning on going to South Bend next May so that might be a good time to pick up an OEM cover. Obviously I'd need to find one that had a road draft tube and not a PCV and maybe even another tube but is there anything else to be aware of when buying one? It is a full flow '62 289 original to the car.

[Kato]

Two things, possible the breather cap is plugged as in #5, and you may be overfilling the engine oil. Drain the oil, measure amount put in, don't depend on the dipstick. Does your car have the bypass filter hooked up and done correctly. Besides too much blowby, if the crankcase oil level gets too high, the crank whips the oil into a frenzy overloading the lifter area and then blowing it out the draft tube. Rather than putting that quart in, next time, wipe the excess off the draft tube, and carefully monitor the level on the dipstick. see if it slows down the loss considerably or not. If it all but stops using oil at the add a quart level, perhaps you are overfilling it and the dipstick is wrong. Just a possibility.

I'll be changing the oil soon so I will do just as you suggest. I have 2 dip sticks and they both show different levels so this could well be at least part of the reason. This is a rebuilt full flow 289 original to the car but that is about all I know at this point. By the bypass filter I assume you mean the top mounted filter? As a full flow mine is on the bottom right of the engine. I misunderstood the previous suggestion of a clogged breather. I will check the breather cap as well.

[Kato]

I think the MAJOR contributor to this Oil Coming out ot the Breather Tube is that Aftermarket Lifter Cover.

I would bet money that those POC Lifter Covers are NOT baffled like the Factory ones are.

The other strange thing is that I've been told the tube should have a hole with a cotter pin about 5 inches up the tube where the mesh filter should be. On this tube there is no such thing so I wonder if it's even the correct tube. I think in light of your suggestion it might be wise to try installing the correct original lifter cover and draft tube. 95% of the oil leak is from the tube, of that I am certain!

[altair]

I don't understand the issue about the baffles in the valve covers. I have an original 259 and there are no baffles in the valve covers. The draft tube is attached to the valley cover and not the valve covers. The air is drawn into the valve covers via the filtered breather caps and is drawn down the oil drain holes and in to the crankcase where it is then exhausted out the draft tube.