Oil consumption...

[JDD]

Originally Posted By: demarpaint
I'd try a piston soak as mentioned. You've gone up in oil grades have you tried going down? Shell did a study, and found in certain instances if the rings are the problem going to a 'thinner' oil actually helped. It goes against conventional wisdom but they showed improvement according to the study.

JMO


+1 ----- it's been brought up on bitog before----sometimes a thicker oil can 'overwhelm' the rings'. You may want to try an HDEO. Shell's HDEOs might be worth a shot. T5 is cheap and is a 'thicker' 10W30 and might just be a good weight for this car and the price it right.

 

[OneEyeJack]

I have the car now, borrowed it from my brother for a trip. Drove 400 miles today and the oil consumption with the Auto-Rx appears to be dropping when measured per fill up. The average speed based on the Garmin was 61 mph and the fuel mileage calculated at each fill up (not the Garmin) was 41 mpg, about average for this car, maybe up 1 mpg over a previous trip, so essentially the same as before. I will have more meaningful oil consumption numbers with I get some more miles on the car. I gave away what was left of the Mobil 1 15w-50 and don't plan on using it any more. At almost a 1k miles since I changed the oil it has started turning completely dark. I happy to see that Auto-Rx must be doing some cleaning.

 

[Kaie]

wow really? 41MPG?

 

[UNC004]

M1 in my car turned very dark very quickly, i was going to run a 5k OCI but i think i'll do the 3k one and switch to PP. I can't explain it, but i just don't like M1.

 

[OneEyeJack]

The mileage range has always been between 36 and 41mpg and this 41 was all highway driving at about 60mph.

There is now over a 1k miles and the top of of oil at every fill up has not been needed. After burning half a quart in the first 300 miles there has been no oil added and at a bit over 1k miles the oil is right on the full mark. This is new behavior for this engine. I drove 400 miles out and now 400 miles back. If this continues then the diagnosis of oil ring problems just may prove to have been correct. It appears that Auto-Rx and cheaper dyno oil is a good combination.

 

[dave1251]

Follow the directions to a "T" with auto-rx. You may have just a problem with you oil rings being gunked up. If you are willing to try a 30 weight oil during your rinse phase maybe you do not use use "heavier" oils.

 

[OneEyeJack]

Dave, good advice, except that I have the rest of a case of Shell 20w-50 to use up. Times are tough.... that's part of the idea of getting the problem under control and keeping the car in the family.

Things are really looking good, so far. This is the best result of any of the non-mechanical remedies, so far.

 

[OneEyeJack]

Well, now that my brother has made the same trip I just made with the car and I just went up to Sacramento and back we are approaching 3k miles. It looks like the consumption is dropping like a stone. There has been less than one quart consumed and that is less than the amount usually consumed in one tank of gas (350 miles). I think we are luck that the problem was one that Auto-Rx could take care of. If it were a broken ring it would mean a tear down.

The next batch of oil is going to be Delo 15w40 as soon as the 20w-50 is used up.

 

[addyguy]

Once this clean and rince is done, do another.

 

[OneEyeJack]

It's now on to Delo 15w40 and a maintenance dose of Auto-Rx. The oil consumption is down from a quart every fill up (350 miles) to a bit less than a quart every 1k miles, a very useful improvement. There is something else going on, too. The oil temp when treatment started was 215-218F taken with a sender through the drain plug. Today the temp during a 410 mile trip was 205F. Same trip, ambient temp today was within 5F of the first trip so this was a pretty fair comparison. There were two trips that measured at the start of treatment and three trips now that treatment has been completed. All represent a 10F drop using a very accurate (read expensive) gauge. There is probably less blow-by and better heat transfer between the pistons and the cylinder walls and an engine that is generally running more efficiently. The gas mileage is up just a bit, too but we were never looking for a mileage increase. I'm wondering if Auto-Rx might just reduce friction when used at a maintenance dose? The dose is 4 oz in 3.7 qt's of oil.

 

[UNC004]

Sounds like a good improvement, real results i love reading about them.

 

[OneEyeJack]

Just a side note. This engine developed valve train noise during the clean phase (at 2,100 miles). I removed the valve cover and isolated the noise to one lifter. When you pressed your thumb on the rocker with the engine idling the noise stopped. The noise was not loud but you could plainly hear it. About half way into the rise phase the noise went away and has not returned. Also what little sludge there was there is all gone. The engine is running well and I set the idle back about 100rpm and it's still very smooth. And the reduction in oil temp has been checked again and it's still about 205F running down the freeway. And now one last observation. The plugs are a shade lighter around the base insulator than the ones that were in the engine before the treatment started. Overall I'd say this engine is more efficient now then before the treatment started as shown by the reduced oil consumption, lower oil temp and the ability to lower the idle speed and still have a smooth running idle. It also appears that the spark plugs are happier, too (if a spark plug can be happy or sad).