Syn oil and leaks

[tagman787]

Well I gotta throw my 2 c in. I have a 85 r80rt I bought last year in prefect cond. with 20k. No leaks for the first 4k on dino oil. Switched to syn 20-50 for the next 6k and after 2k I had leaking from 2 push rods, 1 cyl base, and 1 unknown location I never found. Enough to leave a 5 inch circle of oil under the bike overnight. Went back to dino 20-50 and all leaks stopped. 3k now and not even a spot on the engine, push rod seals are dry. It also quieted my valve noise alot. Anyone else with the same experience?

[RandyB]

Yep. All of those just poured oil from my 89 GS.

Check your oil pressure sender. I had to replace mine after using synth. Never again.

[BubbaZanetti]

i'm replacing my push rod tube seals this weekend, as well as my oil pan gasket and will put some yamabond 4 on the base of the cylinder as well as new o-rings. i'm trying to decide if that'll be good enough to allow me to run synth or if it'll probably dribble out of the rear main seal or somewhere else........

[CTellman]

I bought a real nice '93 R100RT with dino oil in it. I have always used Royal Purple synthetics in everything. Made the change the leaks started. Replace pan gasket with no change. I had no problem with trans, shaft or FD
I have a bad cam seal and I will replace that soon. I have no weepage on pushrod tube seals. The cam seal allows oil to drip down and blow all over looking like everything leaks.
That being said, I cannot believe what a difference the synthetics make. More power, smoother and the oil doesn't get to look like tar.
I know I can beat the leaks and I really enjoy the benefits of better oil.
Campbell Tellman II
'93 R100RT
:thumb

[ccolwell]

Interesting. I used Castrol (auto) Synthetic on my R100 which I owned from about 1986 to 2000. It had an oil stain around one pushrod seal, but never leaked. I used semi-synthetic on the R90S -- no problems, but I haven't put more than 500 miles or so on it since the oil change.

[osbornk]

Well I gotta throw my 2 c in. I have a 85 r80rt I bought last year in prefect cond. with 20k. No leaks for the first 4k on dino oil. Switched to syn 20-50 for the next 6k and after 2k I had leaking from 2 push rods, 1 cyl base, and 1 unknown location I never found. Enough to leave a 5 inch circle of oil under the bike overnight. Went back to dino 20-50 and all leaks stopped. 3k now and not even a spot on the engine, push rod seals are dry. It also quieted my valve noise alot. Anyone else with the same experience?

I had the exact same thing happen to me on my 86 R80RT. The owner had just switched it to synthetic just before I bought it but he had not run it enough for it to start leaking. After a few thousand miles, it got poush rod seepage. I switched back to dino oil and the leaks stopped. That was 10 years ago and it is still oil tight. I switched to synthetic on a 85 K100Rt and the rear seal started leaking. Went back to dino and it stopped.

I don't know what people think they gain by using synthetics. Most of the gain is in their heads. There is not one person in thousands that rides a bike far enough to gain with the use of synthetic oils.

[Manfred]

I've switched to synthetic oil on 2 old (1980 & 82) Yamahas - no leaks. I've recently put synthetic in my airhead. 200 miles and no leaks. I've not read anything recently to indicate that synthetics cause leaks or are more likely to leak than standard oils. Such was not the case 20 years ago.

[AndyMcLain]

Have heard about this problem with synthetics and leaks only in regards to BMW boxer motors and Harley Davidson. Am a big believer in synthetics especially after a very bad experience with a VW Passat turbo and a badly sludged engine on dino oil. I have a 2004 R1100S which I intend to use synthetic in but at 15,000 miles am still breaking in. Oil consumption is only now starting to slow. I understand this long break-in period is not unusual for boxers. I thought perhaps this winter's storage would be a good time to start on synthetic. But not if it's going to leak. Is it possible the boxer motors need a bit of dino sludge to seal properly? Perhaps it has something to do with gasket material? Anyone out there who might know? And be willing to say?

[kgadley01]

I have heard of this. when I bought my first BMW, a 1988 R100RS, I ask the P.O. if he ran syn oil in it. he said no, because he didn't want it to start leaking. I had never heard anything so silly in my life. when I got the bike home I switched it from BMW Dino to Mobil 1 Syn. I kept the bike about 1 1/2 years and never had any problems with leaking. but some people have... :scratch

[108625]

Is it possible the boxer motors need a bit of dino sludge to seal properly?

Well, they are fossils:bolt

[RandyB]

Perhaps it has something to do with gasket material?

It leaked out of the head end of the pushrod tube! Nassssty. Hates synthetic it does....

[osbornk]

I've switched to synthetic oil on 2 old (1980 & 82) Yamahas - no leaks. I've recently put synthetic in my airhead. 200 miles and no leaks. I've not read anything recently to indicate that synthetics cause leaks or are more likely to leak than standard oils. Such was not the case 20 years ago.

You haven't ridden your airhead nearly far enough for it to leak yet. Both my airhead and K bike took a couple of thousand miles before the problem began to show up. Leaks would be far less likely on a 2 year old bike than on an older one with hardened seals.

[Manfred]

You haven't ridden your airhead nearly far enough for it to leak yet. Both my airhead and K bike took a couple of thousand miles before the problem began to show up. Leaks would be far less likely on a 2 year old bike than on an older one with hardened seals.

After I made my post, I recalled that my P.O. was running Mobil 1 in this bike. So my oil change was merely a change in brands, not types, of oil.

Synthetic may show defective seals earlier than normal oil, but it won't cause them to fail.

[PGlaves]

After I made my post, I recalled that my P.O. was running Mobil 1 in this bike. So my oil change was merely a change in brands, not types, of oil.

Synthetic may show defective seals earlier than normal oil, but it won't cause them to fail.

That is just semantics. BMW installs seals designed and intended to contain the lubricants specified by BMW. And except for the latest models those are specs for dino lubricants.

So if a seal contains the specified lubricant without leaks it is not "defective." And if it leaks synthetic and not dino, and you switch back to dino and it works as defined with the lubricant as specified it is not defective.

Sorry about that - but synthetics leaking where dino doesn't is neither an old wife's tale nor a sign that the seal is defective. It is a sign that synthetic leaks past seals that do their job perfectly well as specified with specified dino lubricants. Now if the marketers who hype synthetics could only get it right ....... oh never mind.

[Manfred]

That is just semantics. BMW installs seals designed and intended to contain the lubricants specified by BMW. And except for the latest models those are specs for dino lubricants.

So if a seal contains the specified lubricant without leaks it is not "defective." And if it leaks synthetic and not dino, and you switch back to dino and it works as defined with the lubricant as specified it is not defective.

Sorry about that - but synthetics leaking where dino doesn't is neither an old wife's tale nor a sign that the seal is defective. It is a sign that synthetic leaks past seals that do their job perfectly well as specified with specified dino lubricants. Now if the marketers who hype synthetics could only get it right ....... oh never mind.

I trust that you speak the truth about BMW seals. I wonder why the intelligent Germans (for whom I have great respect and love for the their food, beer, trains, highways, and motorcycles) would go to the trouble of designing such seals.

[PGlaves]

After I made my post, I recalled that my P.O. was running Mobil 1 in this bike. So my oil change was merely a change in brands, not types, of oil.

Synthetic may show defective seals earlier than normal oil, but it won't cause them to fail.

That is just semantics. BMW installs seals designed and intended to contain the lubricants specified by BMW. And except for the latest models those are specs for dino lubricants.

So if a seal contains the specified lubricant without leaks it is not "defective." And if it leaks synthetic and not dino, and you switch back to dino and it works as defined with the lubricant as specified it is not defective.

Sorry about that - but synthetics leaking where dino doesn't is neither an old wife's tale nor a sign that the seal is defective. It is a sign that synthetic leaks past seals that do their job perfectly well as specified with specified dino lubricants. Now if the marketers who hype synthetics could only get it right ....... oh never mind.

[vanzen]

I have used synthetic / semi-synthetic lubricants exclusively in Type-247 engine, trans, and FD
since @ 1982 – without "leaks".
Actually began by using Mobil-1 in 1979 ...
until I received a BMW memo claiming that Mobil-1 20/50 would not maintain proper viscosity.
Then it was back to Castrol GTX dino
until the advent of Spectro Golden Semi-Synthetic.

[keelerb]

I used to put high-quality, slippery oils in my bikes and they leaked! So I switched back to bargain basement off-brand oils that turn sludgey quickly and gum up the seals. No leaks!

In fact, I think a lot of those tiny little passages the slippery oil used to go through to get to the spots that leaked are now completely clogged with oil-turned-to-sludge - thus, the problem is solved!

Hey, bikes are cheap but oil is expensive! Why pay more than you have to?

[tagman787]

Thanks for all the input. I do think that the synthetic has better lube features and is probably a better lube. It will certanly go places dino oil will not (like thru small rubber seals). I think I'm happier with no leaks. I'm glad I wasn't the only one.

[47512]

I have a 75 R75/6 with 168,000 miles on it, it's been run on mostly Torco 20/50, sometimes GTX 20/50, other than a weep here and there it's never had a oil leak, why change? I also have a Norton Commando, I've owned this machine for 30 years and it never had a serious oil leak, After a top end rebulid and 1000 miles on dino oil I switched to synthetic (Amsoil) 20/50 because this is suppose to be the hot tip for tender Norton camshafts. The machine developed oil leaks from places it never leaked before. I changed back to my standard dino I've used for years, no more leaks, It has a few weeps (it's British) but no more on the ground.

I have a R1200R that has dino in it, it has no leaks and uses very little oil. You can do two dino changes for the price of one synthetic change.

If BMW thinks their machines will live a long happy life with Spectro in them, whitch is a good product, but not outstsnding, why mess with synthetics?

Ken G.

[PGlaves]

I used to put high-quality, slippery oils in my bikes and they leaked! So I switched back to bargain basement off-brand oils that turn sludgey quickly and gum up the seals. No leaks!

In fact, I think a lot of those tiny little passages the slippery oil used to go through to get to the spots that leaked are now completely clogged with oil-turned-to-sludge - thus, the problem is solved!

Hey, bikes are cheap but oil is expensive! Why pay more than you have to?

I have had engines apart far enough to find sludge if it were there - with more than 350K miles on dino oil - and found no sludge. If you are getting sludge with any modern API SG oil you are certainly doing something wrong.

[keelerb]

Just attempting a little (yeah, I know, very little...!) humor there Paul.

[PMonk]

put some ground up teflon in, that should stop the leaks.

[RandyB]

put some ground up teflon in, that should stop the leaks.

To be replaced by one leak at the rear main....

[67461]

FWIW,IMHO, This oil thing gets beat to death. I've run both in different bikes and still do. Both work well. Tape some thermistors to cases (engine, tranny, final) and I believe you will see sigificant reduction in temp on syn. . Oils last a lot longer than most of us use them. Modern eguipment is pretty well sealed. Oils coke from high temps( in engines) and get a little contamination from products of combustion( carbon, sulfur, water vapor). Over the road tractors run syns in drivetrain( other than engine )100's of thsd's of miles. I run syn in my R100R because I believe it reduces temps either by reducing friction or it's ability to wick away heat. I am doing this to prolong seal life which also degrades from heat and time. Yup it weeps some, even around new crush washers when it gets down to about 8 F ,I ride if there's not ice. If Humans build it, it will break or leak. My German upbringing pushes me towards being anal-retentive, but with counseling I'm gradually overcoming the illness. Bottom Line: about every 5-10,000 I hose Homer down with some brake cleaner and we tear down the road again. Homers my good buddy and we're not happy unless we're rollin'. Use what you like , check it ,change it, and for goodness sake- GO RIDE!