Hi all;
My mechanic and I have been discussing what is the best way to slow down oil consumption on our 1995 850. Is it better to use a heavier oil say 20/50 rather than the 10/30 what has been used up to now OR is it better to put additives in with the 10/30? The whole idea is to slow down the consumption of motor oil with out harming the engine in any other way.
Thanks for any and all ideas, Brad

Hi, thanks for this guidance. I don't know all that much about engines so I am not sure why oil loss correction solutions depend on whether the problem is through valve guides or past the rings? Do you know if there are other items beside the flame trap, which I do not have, that can affect crank case venting such that extra oil loss occurs? The EGR valve has been mentioned. Are there other parts that need to be cleaned or changed?
Brad

just hit 384000 and i dont burn any oil. because of various minor leaks it was recommended to me to switch to 15/40. used it all winter up here in siberia, canada with no problem. between oil changes i even throw in a litre of 20/50. one thing ive noticed is how the engine is quiet immediately after startup. i wish i had of made this change a long time ago.

Screw tha addatives, they rarely do anything. I would just do a good Dino oil, maybe 15W40 (Don't know where you live) And change it every 3K miles. Look at bobistheoilguy.com for good info on oil. If that doesn't work, then maybe you have other issues to deal with.

Do you know why your 850 is consuming oil? Make sure it isn't a plugged flame trap causing elevated crankcase pressures. Assuming it is either slight internal burning due to worn valve guides or worn cylinders or slight leaks such as the crankshaft seal then you might be able to reduce the loss rate with a better oil choice.

I would not go as heavy as 20W/50. Volvo's recommended oil for the 850 (at least according to my '96 owner's manual) is 15W-40, which is a heavy duty fleet grade oil dual rated for gas and diesel engines. Chevron Delo, Mobil Delvac or Shell Rotella 15W-40 would all make good choices.

Another route would be to go with one of the High Mileage formulated oils such as Valvoline MaxLife in a 10W-30 weight. These oils are on the thick side of their grade range and include some seal swelling agents which can reduce certain kinds of oil leaks.

Volvo's manual specifically says not to use 10W-40 grades, but I suspect that is because some of the older formulations of 10W-40 were prone to rapid degradation due to the amount of VI index improvers used. Today's oils mostly use higher grade base stocks and better VI improvers, so I dont' think it is as much of an issued today.

Presently I am running Valvoline Maxlife Synthetic 10W-30 in my '96 850 and it seems to have stopped the slight oil consumption I was previously getting (110k miles on the car now).

I would not use any of the additives out there. It is much better IMO to use a fully formulated and tested lubricant and not brew your own with a combination of oils and additives.

Bottom line, try a High Mileage formulation motor oil from one of the major brands in a 10W-30. If that doesn't get you where you are trying to go, then try a 10W-40 High Mileage oil of a 15W-40 fleet oil.

John

I might first try to identify where the oil is going. Valve guides?

Look in your owner's manual for the approved oil weight/temperature chart, I think they say you can go to 15W40 if it doesn't get too cold where you drive.

-BTC

'98 V70 T5 5-speed, 161k mi, front IPD stabilizer bar, rear factory HD bar, Bilstein HD, Volvo strut tower brace and skidplate, e-codes, V-1, Mobil-1 since new

"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair." -- Douglas Adams (1952-2001)

Hi, thanks for this guidance. I don't know all that much about engines so I am not sure why oil loss correction solutions depend on whether the problem is through valve guides or past the rings? Do you know if there are other items beside the flame trap, which I do not have, that can affect crank case venting such that extra oil loss occurs? The EGR valve has been mentioned. Are there other parts that need to be cleaned or changed?
Thanks, Brad