Excessive oil consumption

[imbodie]

Originally Posted by Jason

You might try BG109 compression restore. Its supposed to be able to free up stuck rings and dissolve carbon build up. It would be worth a try I doubt your consumption will get any worse!

Jason

I can't find BG109, the local parts stores have never heard of it. I went to the website and there are three sites in my town that are listed for special services but it doesn't mention that BG109 is available at any of them.

I did try Risolone (sp??) and have used several cans of Seafoam. The Seafoam would seem to fix the problem for aprox 4 days, but eventually the car would go right back to using oil again. This was just pouring the seafoam into the oil, or into the fuel. I haven't tried pouring it into the valve cover and letting it set.

Is BG109 THAT good? I know I've seen quite a few posts about it in the forums here.

-Tim

[imbodie]

Originally Posted by piper109

I hate to tell you this but my engine used a quart in 25 miles. When I pulled it down, the top piston ring gaps were more than 1/4". One was broken.
Amazingly it would crank up quite easily and did not seem to use oil.....until you drove it.

The engine and had less than .001" wear in the bores and I rebuilt it using the same pistons. Same engine will use a quart in about 2-3000 miles now.
The starter ring had some teeth missing too so I had to remove the engine anyway.
Steve

Boy that sure sounds like what I'm experiencing.
I took the car to my TRUSTED mechanic who has worked on vw's that I've owned for 20 years or more and he suggested a compression test (all injectors pulled) for a good idea of what was going on with the engine.
He felt that the compression test would be a better indicator of rings or valve issues before I just tore into the engine.
I asked him for a guess as to where my oil was going and he felt (with out the compression test) that it was the valve guides and offered a good explanation as to why it would most likely be the valve guides. Stating that this engine pumped a LOT of oil to the top of the motor to keep the cam shaft lubricated and that the oil was filling up the valve tubes when they were closed and draining out when they opened up.
Ok thats my best paraphrase of what he said.... it sounded much more concise when he said it.

So what do you guys think? would a compression test differentiate between valve guides and rings?

-Tim

[v8volvo]

Originally Posted by imbodie

So what do you guys think? would a compression test differentiate between valve guides and rings?

-Tim

Not necessarily. It would tell you if your compression rings are OK or not, but it wouldn't tell you anything about the condition of your oil control (scraper) rings. If those are gummed up it may still have fine compression -- as it possibly does if it starts well -- but it could still be experiencing major oil consumption via the rings since oil will get up past them.

You may want to try checking what your blowby situation is, since that often accounts for the major portion of oil use in tired engines. If your engine runs OK but has a lot of blowby, there are things you can do to keep oil use under control without having to get into major engine repairs. Here are a couple tests to start with. First, disconnect the breather tube from the valve cover and plug the opening in the valve cover with a cap (5/8" heater hose block-off cap available at your FLAPS should work fine). Then run the engine with the oil cap off and see how much air/oil vapor is being blown out. Even a normal healthy diesel engine will push a certain amount of crankcase pressure due to their high compression, but if there is a torrent of air coming out and blowing oil everywhere, then you have found your problem. See if it blows the oil cap off when you set it on the hole lightly (not screwed on).

You can then confirm this test with a second one. Remove the cap you put on the valve cover breather connection, and getting a long piece of appropriately-sized hose that you will run to a container. A few feet of hose running to something like a juice bottle temporarily mounted on one side of the engine compartment ought to work. It's best if the container is something clear so you can see what's going on inside it. Make sure everything is secure and then go out for a drive. If it is really using a quart every 25 miles, then driving 5-10 miles or so ought to be enough. Drive as you normally would. Then stop and check how much oil has accumulated in the bottle. If there is a significant amount, then blowby is unquestionably the cause of your oil use.

If both of these tests show no blowby and no oil consumption, AND a compression test shows your compression is perfect, THEN I might start to believe it is related to valve guides or seals. However, history of these engines shows that 99.9% of the time rings are the issue when you have symptoms like these, and chasing other stuff is just a waste of time and money. Using that much oil that fast, your valve guides would have to be unbelievably sloppy, and that just isn't considered much of an issue with these engines. You can try the above tests on your own before paying for a compression test, and they will give you a pretty good idea of what is going on in there.

[piper109]

I believe you will find that the valves are worn and sloppy. I predict 5 thousands on the inlets and 15-20 on the exhausts........as well as the worn rings.
I believe this is how those engines wear on the wrong oil. It wont be one or the other, it will be both.
Symptoms of worn guides are that it smokes blue when you first start it up as oil leaks onto the top of the valve faces when the engine is stopped. Once it burns off blue smoke will cease then on an overrun from high rpm you will fog the neighborhood.

Steve

[Jason]

You could get a decent amount of oil through the guides if the valve seals are petrafied and flaking apart. These engines are known to wear rings and have compression issues, especially the NA cars because of softer blocks, and more soot accumulation around the rings. The BG 109 is good stuff. We sell it at my shop. I don't know if we have a bottle of it right now, we only keep one in stock as most people dont know what the hell it is. We can order one and get it next time we get stuff from BG. I think it goes for about 20 bucks a bottle. For the consumption to be that high, I would suspect lots of wear, or totally crapped up and stuck rings. As I said, the oil consumption really cant get much worse, but you might as well do a compression check before you go any further.

Jason

[imbodie]

Originally Posted by Jason

The BG 109 is good stuff. We sell it at my shop. I don't know if we have a bottle of it right now, we only keep one in stock as most people dont know what the hell it is. We can order one and get it next time we get stuff from BG. I think it goes for about 20 bucks a bottle. Jason

So, can you guys ship a bottle to me if I can't find it locally?

-Tim

[imbodie]

Originally Posted by v8volvo

If it is really using a quart every 25 miles, then driving 5-10 miles or so ought to be enough. Drive as you normally would. Then stop and check how much oil has accumulated in the bottle. If there is a significant amount, then blowby is unquestionably the cause of your oil use.

Ok.... ran a tube from the valve cover vent to a 1 gallon Rotel oil jug (emtpy of course) drove just shy of 25 miles varying my driving style from town to interstate.

GUESS WHAT I FOUND????

I had almost blown an entire quart of oil in the 25'ish miles that I drove.

Ok at this point I believe my entire 4 quarts of disappearing oil in a 100 mile round trip were all spent through blowby. I also think a LARGE part of the oil on the air intake probaly came from the same blow by. Leaking down from the big air intake tube to the top of the manifold.

I'm going to google it after this post, but now that I know its almost all blow by... what exactly does this tell me?

Thanks again,
Tim

[v8volvo]

I'm not too surprised to hear that. I think it would be hard for an engine to burn oil that much that quickly any other way besides through huge blowby.

OK, by doing this, you have identified the source of the problem. What this tells you is that you have serious issues with the sealing of your rings. That can be due to one of the following three conditions, or any combination of them: 1) stuck/crudded-up rings; 2) worn rings; or 3) worn cylinder bores. Now you have to decide what to do about it. If #1 is the cause of your problem, you may be able to free up the rings somewhat over time by using different oils and/or additives. Since you said gasser oil was routinely used, I would bet there is at least some ring sticking and coking going on, which you may be able to help with "fluid fixes." However, if #2 or #3 are what is going on -- and to at least some degree they almost surely are -- then your only "true fix" is an engine rebuild.

How many miles does the motor have on it? If it starts and runs well, you might be able to get by for quite a while simply by constructing some way of trapping the blowby oil and returning it to the sump. That will at least give you time to run the car for a few thousand miles and try experimenting with options for unsticking the rings. Jason built an oil separator system for his car that was done very nicely. You could try doing something similar, and results will probably be good. This will prevent you from running out of oil, or experiencing a much more scary potential problem that I'll describe below.

The dangerous thing about driving it the way it is now is that you could experience a runaway situation. Your level of blowby is so high that, under certain conditions, the engine could start to run on the oil vapors that are being pumped into the intake manifold and "run away." It will get into a self-perpetuating feedback loop that will cause it to run faster and faster and faster. Once that starts to happen, you have no way of stopping it -- turning off the key will not help at all, and since your car is an automatic you are not able to stall it out. You only option would be to let it rev to the moon until it self-destructed, which would be a sad ending, and potentially a dangerous one if you couldn't get off the road fast enough.

So, I would run it with the crankcase vent at least routed to an external container for now, like you did when you performed the blowby test, to prevent the possibility of runaway, and then construct something more permanent. Then you can see what kind of results you get from BG 109, LM MoS2, etc.

[Jason]

I don't know if you would be able to seperate out that much oil. The setup I did was to cut down oil into the intake mostly because I run the shit out of my car all the time and the high rpm's really push some oil up into the valve cover. It did cut down on oil usage, but I don't use anywhere near the oil you are talking about. I may use a quart every 500 miles the way I drive it.

Jason

[Jason]

I am amazed that it starts at all with that much wear, I would think you would have almost no compression to be able to have that kind of blow by.

Jason