While I have searched this issue and learned a great deal from all of you, I would appreciate any further ideas you may have to help diagnose the probable cause or cure for blue smoke from my recently acquired Monte. Its the 3.0l, 1990, LWB, 180KM, auto, with good compression on all 6 cylinders (between 135-145 psi.) I recently replaced the valve stem seals and noted the guides were OK and had been updated with retaining clips but I still have clouds of blue smoke starting about 10 seconds after startup and lasting for only a couple minutes or blocks plus it puffs blue once under hard acceleration. It doesn't visibly smoke at idle or stoplights. I disconnected the PCV hoses with no effect. By elimination, I am thinking its worn/plugged oil control rings even though the compression rings must be OK? I tried Alemite CD2, overnight soaks in Marvel MO and ATF, and Sea Foam in the oil for 100 miles. No improvement evident and the CD2 made it smoke continuously. Any help, ideas, or questions would be appreciated and thanks for reading this long description. <img src="/forums/images/graemlins/confused.gif" alt="" />

You have made a pretty complete diagnosis of the problem. What did the plugs look like? Were they oily?

Thanks for the quick reply. The plugs are not particulary oily or wet and are a fairly normal, gray color. They are not, however, as dry or as whitish as my newer, well running vehicles.

I hate to let it go at that but it really sounds like you hit it, worn or clogged control rings. If clogged due to a poor oil change schedule (previous owner), some of those restorer/ flush/ smoke stopper additives may give a result. I forget who but there is somone on here that is testing on of these and he is pretty convinced so far that it is working. Maybe someone remembers who it is and will read this. <img src="/forums/images/graemlins/kewl.gif" alt="" />

I assume that your valve guide to valve stem tolerance is ok based on the guides being replaced with the new guides with clips plus your installation of new valve seals. Assume guides were done by a machine shop and clearances were checked. I also assume that based on the continuous smoking with CD2 that you added it as a cleaner through the carb. I have had good luck in freeing up stuck oil rings by adding it in the motor oil as an additional detergent. I have even used 2 bottles with an oil change. You might also try using a 15w40 higher detergent oil rated for diesel engine service for several thousand miles before changing. There is really no good way for removing heavy carbon and oil deposit buildup from the oil control rings except tearing the engine down and reringing it. I would try the double CD2 and/or diesel oil with higher detergent for a least another oil change period before tearing into it. It will take 1500-2000 miles or longer to slowly dissolve the deposits if it is going to.

89raider,
Thanks for comments. I added one bottle of the cd2 to the oil (new Chevron Supreme 40W) and ran the Monte off and on for a couple hours over a couple days; it just smoked really bad the whole time so I drained it. I have heard about Shell Rotella and similar diesel type high detergent oils and agree it probably is worth a try before reringing it which is probably the inevitable solution. Thanks again for your help and advice.

I might try about half a quart of atf in there. It's worked for Bama rednecks (me included) for years. I've even seen it used in the gas tank and crankcase, on (God might forgive them, but not me), a 300SEL 3.5 convertible, and it worked, 'til they treed it drunk on home made wine (the Welches/yeast version...).

Here I go again. A newer product for cleaning your engine internals is;

www.auto-rx.com

It has been tested through engine teardowns and many, many testimonials to work as described. It is supposed to help with a myriad of problems including clogged ring packs. For the ring pack problem it is supposed to work fairly quickly (say 500 miles). The product is $25 including shipping, but you have to do a few short interval oil changes (1500 mile, 2000 mile). Follow the directions and oil change recommendations explicitly and use dino (not synthetic oil). If you want to discuss it with some oil Freaks <img src="/forums/images/graemlins/zombie.gif" alt="" /> go to the forums on;

www.bobistheoilguy.com

Look under the oil additives section.

The other suggestion to use a Diesel oil (Shell Rotella or Chevron Delo) is good for cleaning your engine, but probably not effective enough at cleaning ring packs.

The ATF suggestion is a myth. IMHO.

The only other flush I would ever put in my engine is the Amsoil flush. Anything else is too risky.

Flame me if you want, but I believe ARX is an amazing product. No, I do not work for the company.

If you use it please let us know what happens. Good or Bad.

Oh, I remembered something else. Since you have pretty good access to your spark plugs and are willing to "soak" you pistons/cylinders. There is another suggestion on the Bob is the Oil Guy site. It is called a "Molasoak". Search for it. It is a combination of a couple cleaning products and is supposed to work well.

Regarding Oil/Engine additives/Cleaners, I read something once that made a lot of sense to me. When considering any of these products the best way to look at it is to be an "open minded - extreme skeptic". Meaning that; while it is possible for a product to help your engine, you should be extremely skeptical of all claims. Search for ARX or Auto-RX on the internet and decide for yourself.

Winston,
I appreciate your input regarding auto-rx and "molasoak." I have been evaluating auto.rx and agree it may be my best chance for a fix out of a bottle, if one possibly exists. The dialogue on Bob's site certainly is interesting and there are many positive experiences. I have been trying the cheaper, quicker ideas first, but auto.rx is probably next on my list. I have never heard of molasoak, but I'll search it out.
I'll certainly will report back if I try auto-rx and/or experience any other successes or failures in my attempts to stop the smoke. Thanks again. <img src="/forums/images/graemlins/kewl.gif" alt="" />