Up until May of 2007, my 1986 244's engine was driven 55k miles at a very mild pace (around town and several 300-400 trips). Never burned any oil - at oil change time, the dipstick was always full. Dyno Oil used only (Castrol 10W-30).

Starting in May, it stared its new life (we moved) and now goes 50-60 miles per day at about 80mph. I recently switched to full synth oil (Castrol 10W-30). I am 2,000 miles from my last oil change and last night I just discovered that I was a half quart low! There is a bit of seepage at the valve cover (near the firewall), but that has been there a long time and is not significant. So I assume that I am burning oil. Could it be due to my new driving habits (high RPMs) or from the type of oil (synth)?

Do rings get worn-in differentely based on the driving habits (majority low RPMs), and when you start giving these engines higher revs, the rings are not happy??

Thanks for any input!

At 80mph each one of your pistons fires four times as often as at 20mph. Also, at 80mph the throttle plate is open furthur because you are fighting considerable wind resistance. The increased throttle plate angle increases combustion chamber pressure, thus increasing crankcase pressure, due to some normal blow-by which will occur. Synthetic oil is thinner (even if the viscosity numbers are the same), and this will increase the problem you are having. Every product on the market designed to stop oil burning is as thick as honey or molasses.






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'89 silver 244DL in Milwaukee WI

I have had old-timer wrenches tell me that running an high mileage engine hard that had been babied all of it's life could cause compression ring damage in rare cases. The explanation was that the extra "stretch" on the piston and rod (with the harder running) might allow the compression ring to kiss the ridge at the top of the cylinder.

I did have a 1975 Chevy with a small-block V-8 that started burning synthetic at about 36k miles and when I switched back to dino stuff the consumption returned to zero. I couldn't see any smoke, there were no leaks, but the oil was going somewhere!

Your rings are just fine. It is your sudden high speed driving. Replace your valve cover gasket so you eliminate the dribble. And check the hoses at the flame trap, they need to be clean. The little round screen in the flame trap should be tossed in the garbage so it doesn't get clogged up again.

And slow down about 10mph, unless you are in a 75+mph zone :)

Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)

You may be building up crankcase pressure during the prolonged high speed driving. Have you checked the flame trap and all associated hoses? Synth won't cause an increase in oil burning and I've never seen a red block burn oil with less than 150K on it if it had any maintenance at all.

My '88 uses less than 1/2 qt per 4000 miles between changes and has since I got it at 113K.
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Dave Shannon
Durango, CO
'63 P-210
'67 1800s
'88-240
'01 Wrangler
'06 F250 Diesel 4X4
my pages

I replaced the flame trap and all related hoses/components when I got it five years ago @ 43,000 miles. I guess I could check them just in case....

Thanks

You should check and clean your flame trap and hosing at least once a year imho. If you don't have vacuum at the oil fill hole at idle, you may need to check your oil separator. Replacing a clogged oil separator fixed the lack of vacuum at idle in my recently purchased 93. The switch to synthetic decreases the clogging of the oil separator significantly.

Ron
93 245, classic#24
87 745, soon to be parted
near Brantford, ON, Can