I hope I don't duplicate here. I fat-fingered the keyboard and lost my reply.

I have 195,000 miles now and no smoke, ever. not even a puff. I starting putting in Lucas around 165,000, right after I bought it. 10 or 12,000 mile oil changes and consumption is down to probably a quart every 4 or 5000 miles. But, my X5 is DRIVEN.... and runs perfect.

For the Naysayers...
Why would anyone not use Lucas to fix this problem? Has someone had a bad experience with it? Is someone more experienced with piston engines than Lucas automotive products and be able to explain why its not a good idea? Why would Lucas "Oil" break a BMW engine but none of my Fords?

LOS basically increases the oil viscosity making it more difficult to leak through the valve seals. Its not a fix, it only creates an acute fix for the burning, while causing more chronic problems down the line from additive displacement, foaming and reduced flow during coldstarts etc.

Interesting. Do you have a direct experience with LOS? Would using a high viscosity oil instead of LOS cause the same problems you mention? I spoke to a mechanic about my valve stem seals issue and he suggested to use a heavier oil such as Mobil 1™ High Mileage 10W-40 if I want to delay a proper fix.

DavidClass, do you have any issues with cold start that Omerta mentions?

Perpetually adding an oil additive isn't actually fixing the problem. The problem is that the seals are failing. Putting in an additive hides the issue by swelling up the failing seals. It's really a temporary fix.

There are accounts where people skip putting in additives which are currently working and the smoking reoccurs. Then when the additive is put back in, it doesn't work because the seals don't swell back up.

You may run the engine forever using the additives and never have a problem. If so, that's great! But it's not really fixing the root issue of failing seals. Only replacing the seals fixes the issue.

BTW, here's a good discussion of the Lucas Oil Stabilizer. Basically, quality oils have additives in them to reduce wear on your engine. Lucas Oil Stabilizer doesn't have any additives so you're basically diluting your quality oil with that product.

Lucas Oil Stabilizer? | OTC and Third Party Oil Additives | Bob Is The Oil Guy

Not a great anology but this sounds to me like patching up a leaking bicycle tube rather than replacing the tube with a more sturdy one. Given the quotes I'm getting for a proper fix are nearly 50% the value of the car, it seems a patch makes more sense at this time for me, albeit I have to make sure to refresh the patch at every oil change.

The analogy fits. And can't blame you for not wanting to pony up for the fix because it's definitely expensive.

The shop which did my repair told me that other than the stinkiness of the smoke and oil consumption, there's not much harm to the failing valve stem seals. They haven't seen any issues with things like the emissions systems as a result of the smoking.

I can't debate anyone on this thread because I don't know what it does or how it does it. its magic maybe. I know what it did for me. I've driven it pretty hard for 30,000 miles in two years, including pulling a 3000 pound popup camper 4000 miles out of a 5000 road trip. Jack rabbit starts and nose standing stops are the norm for this X5.

I'm not encouraging anyone to do this. My car was not driveable because of the embarrassment of the smoke screen that any batmobile would be proud of.

I fixed it with 24 dollars worth of Lucas. (From Walmart)

I've used LOS in a 2000 TDI Jetta I drove to 450k

It would cause the same problems with a lower viscosity oil minus the foaming (air entrainment).

Since the smoking is when the oil is hot, you would likely need to up the oil to a 10W50 or so to compare... but that effects your VANOS, cam followers, chain tensioners, and all hydraulically operated parts as well. Not an acute problem, so you won't likely see a smoking gun for a while.

I went back and read some of that thread from the Lucas link above. Pretty funny stuff. I'd wager that none of them that hate it, ever had or saw a Lucas oil caused engine failure. I read lots of opinions against oil additives and several that are for it, The ones for it, at least had supporting personal use of the products. I didn't read one post that said " I used it and blew up my BMW engine".

I run 20w50 in mine (hot climate here) and still have the smoking. Oil consumption is definitely way down to maybe a quart every 5000 miles as yours is but the smoking persists. :(

David, I don't think it's an issue so much with the product as I don't think Lucas would risk the liability involved if it were indeed a danger to engines. What I think it is more an issue of for people are that it isn't actually fixing the problem but "band-aiding" it. It's a purist train of thought for sure (and one I am guilty of depending on topic) and is probably why you are seeing some resistance...

Bottom line if it works for you... awesome. Replacing valve stem seals is a helluva lot of work and I might try the Lucas additive as well if it holds no danger to other systems. I always equate stop leak products with coolant stop leak products where you end up with chunks of silica type material all over the place.