I have two non-turbos: 1980 242 DL and 1989 245 DL that are daily drivers. Both have about 300k and 200k miles and head gasket replacement within the past year. I have owned both vehicles for 2 years and diligently cared for them (prior to that, they were in Washington State and Massachussets and relatively neglected).

My goals with considering synthetics are to prolong the engine life and clean up gunk. I've read Mobil 1's webpage, the list-serve, and FAQs and am confused about the risk of oil leaks on converting to synthetics. I've seen a few anecdotes about rear main seal leaks, which scares me because I really don't want to have to replace them.

Are my goals reasonable?

What is the risk of oil leaks?

If so, what grade would be good (5W-20 or 10W-30) for California (temps between 40'F and 80'F)?

Thanks in advance

My 1988 240 has unknown miles as the odometer seized up at 29,000 miles. I put a few cycles of Wal Mart pure synthetic motor oil though it. The first two cycles dislodged some black lacquer type plaque that I found in the oil that I drained and totally clogging the flame trap. The last few oil changes have been clean and clear. I have no oil leaks and no oil consumption that I can see. I change my oil based on my rough estimate of milage. Due the hurricanes last fall I was not able to change the oil on time and the estimated milage went to around 10,000 miles. I just changed the oil two weeks ago. This time I changed to Mobile 1 as the Wal Mart in Florida City, FL cannot seem to keep the Wal Mart synthetic oil in stock. For what it is worth the flame trap seems crystal clear every time I check it out. I pull it; blow it off with compressed air and reinstall it.

I have couple friends who sell Amsoil Synthetic oil in California and Oregon. I have 3 vehicles Chrysler TC 2001 (108K) and 97 (215K) and a brick 1990 240DL (182K). Both of them does not want to sell me Synthetic oil because it will lease. According to them, my vehicles are sealed with the gunk from the old oil and using synthetic will clean the gunk and will leak.

Hope it helps..

doesn't matter. Red block volvos last a long time because they are well made, and in fact, usually in spite of their owners.

Is there oil in the car? Good.
--
Stef (81 245 B21A SU M46 3.91 330000km, 81 244 BW55 3.31 220000km)

If worried about leaks, run a couple of treatments of autorx www.auto-rx.com first to clean them out and condition the seals, then do the switch,10w-30 would do the trick.
--
-------Robert, '93 940t, '90 240 wagon, '84 240 diesel (she's sick) , '80 245 diesel, '86 740 GLE turbo diesel, '92 Ford F350 diesel dually

Some leak, some don't, it seems.

I've changed 6 cars, (3 Volvo red blocks) over to Mobil-1 at mileages ranging from 33k to 265k. No new leaks, no change in the old ones. With mostly highway driving in a mild climate, I changed oil and filter at 10k mi intervals, which is what Volvo recommend for regular petroleum oil in my non-turbo 940 owner's manual, for non-severe service.
--
Bob (son's 81-244GL B21F/M46, dtr's 83-244DL B23F/M46, my 94-944 B230FD; hobbycar 77 MGB, and a few old motorcycles)

Higher mileage cars could have a tendency to leak, as what was keeping the leaks in was the gunk. The seal is leaky already, but just masked because it's being held back.

Synthetic has a tendency to wisk that gunk off, "creating" the leaks.

For a non-turbo, I wouldn't fret so much. 10w-30, and you're good.

-- Kane
--

While I would never deliberately mislead anyone, take into consideration that any info and advice was provided at no cost to you.

If your engines are still good enought to pass the strict California Smog Check with that kind of mileage you are probably safe using synthetic. But I would also worry about the rear main seal if its still original. I say switch to synth if you are prepared to deal with a rear main seal leak, or even better, replace it before hand anyway. How about switching the car with the lower mileage first and see how it goes. Or you can brew your own mix of synth and regular oil. Start with one quart synth on the first oil change and increase the proportion every oil change after that.
Good luck
Justin

do you think it would be fine to always have 3 parts regular and 1 part synth? Wouldn't this be like a slow cleanse of the engine with a low chance of leaks because gunk moved would be slow and synth blend might condition seals when gunk is moved? i dunno im not great with cars but seems to be best of both worlds.

89 volvo dl 202,xxx

There is really no danger in mixing any proportion of synth and regular oil as long as they are both apropriate for that engine on their own. So there is absolutely nothing wrong with using home brew at every oil change.
The oil companies make a lot of profit by selling "synth mix" oils to the public. But you never know exactly what the proportion of synth to dino is in those oil. In fact a lot o those oils at 90% or more regular oil and very little synth. At least if you make your own brew you know exactly how much of each is going in.
Good luck
Justin

DONT DO IT , i have had nOTHING BUT leaks ever since i switched to the synthethic oil

Please tell me more about your vehicle, esp year, miles, where you had the leaks and why you think the leaks happened?

mine is a 244glt ,1984 with 230km , I did an engine flush and then did the synthetic , ever since the oil change the car wont stop leaking off the rear main seal

I switched to synthetic when I bought my 1992 240 in fair condition at 115,000 miles. It now has 150,000 and doesnt' use or loose a drop (knock on wood). However I am switching back only because I don't think it is worth the $ for a normally aspirated 240. With frequent dino oil changes, the internal engine is likely the last to go.

Fully agree. I have taken several Volvos to over 200k, all NA, all regular dino. Never a problem related to lubrication. Presently have a 740 with 260k +. All dino, etc. -- no leaks, using less than a quart between 5000 mile OCI's. My oil of choice since my "wild and crazy" Triumph days(Spitfire, TR-4, TR-6) has been Castrol GTX dino, and always 10w-30. I have never really seen the sense in synthetic. I'll stick with success . . .

Allen

Sure, the old tractor engine does not NEED the fancy oil, but it is still no waste. With extended drainage intervals the costs are pretty well the same even if you do it yourself, and even more so if you pay a garage for servicing.

You also seem to miss one important advantage: convenience. One-half of one-third the frequency of oil changes and less need for flame trap degunking need that much less time.

Such other benefits as less oil to dispose of may not appeal to everyone, but a marginal increase in the engine's willingness to rev and start in the cold would.

George Antony