15w50? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

adlerk · 10-08-2009, 08:10 AM

Hello Out There,

I'm new to this forum. Lots of good info here...thank you!
I bought a '99 Boxster with 80,000 miles 4 weeks ago and LOVE it...It's by far the most amazing vehicle I've ever owned or driven! although I was very sad to find that when it sits over night there are always a few drops of oil on the garage floor.
I've read that if it is driven often (so the seal doesn't dry up) and if I use a heavy weight oil it may cure the leak.

My questions are:
How often is often? Every day? 3 X a week? For how many miles?

and...

Would Mobil 1 15W50 be okay to use in Va. where the temperature can drop below the 20's in the (upcoming) winter months?

Also...

Will I wreck the engine if I don't get the leak fixed? and how much does it typically cost to replace the RMS?

Thanks so much for help!

-Sunny

10-08-2009, 09:17 AM

15W50 is definitely too thick to be running for the winter in your climate. While not a recommended Porsche viscosity, for summer use in Arizona, that's one thing, but for winter in Virginia it's not a great idea.

You need to determine where the leak is coming from before assuming it's the RMS, as it may just be a valve cover or oil pan leaking. If the leak is coming from the joint between the engine and gearbox, it is likely to be the RMS, though it could also be the IMS seal leaking. The gearbox needs to be removed to determine which, and to allow access for the repair. If you do pull the gearbox, it would be a great time to update the IMS bearing and replace the clutch, as the added labor is negligable.

The concern with allowing the RMS to leak is that eventually, as the leak gets worse, it will coat the clutch with engine oil, causing significant slip, and rendering the clutch worthless.

Often use would be defined as at least twice a week. Anything mechanical doesn't like sitting around, and that includes cars, motorcyles, airplanes, boats, locamotives, etc.

Brucelee · 10-08-2009, 12:02 PM

Red Line makes a superior 5W-40 which would work both summer and winter in Viginia.

Good luck.

Flavor 987S · 10-08-2009, 04:50 PM

The only Porsche approved 50 weight oil is Mobil 1's 5w50. Hard to find in the USA, but you can get it.

Don't use 15W50.

5W40 is a great choice.

An RMS repair, if this in fact your issue, is about an $800 repair. Pretty "cheap" by Porsche standards.

Cloudsurfer · 10-08-2009, 07:52 PM

While not Porsche approved, I'd be ok running 10W50 or 15W50 in a very hot environment, but certainly not anywhere where you're going to see cold weather.

rangersplash · 10-27-2009, 08:31 PM

Quote:

Originally Posted by Cloudsurfer

While not Porsche approved, I'd be ok running 10W50 or 15W50 in a very hot environment, but certainly not anywhere where you're going to see cold weather.

I just bought 10W50 M1 tonight and am going to change the oil tomorrow. I assume I'm okay down in Mobile, AL on the gulf coast? I think in about 4 months I'll be moving to San Diego so that should be okay too Right?

Brucelee · 10-28-2009, 05:05 AM

Quote:

Originally Posted by rangersplash

I just bought 10W50 M1 tonight and am going to change the oil tomorrow. I assume I'm okay down in Mobile, AL on the gulf coast? I think in about 4 months I'll be moving to San Diego so that should be okay too Right?

I am not aware of anyone making a 10W-50 oil. I think M1 only comes in 15W-50. That seems a bit heavy, even for SD, which can get quite chilly at nightime.

I would stick with the 0W-40, esp in winter.

Good luck.

rangersplash · 10-28-2009, 06:14 AM

Quote:

Originally Posted by Brucelee

I am not aware of anyone making a 10W-50 oil. I think M1 only comes in 15W-50. That seems a bit heavy, even for SD, which can get quite chilly at nightime.

I would stick with the 0W-40, esp in winter.

Good luck.

Maybe it was 5W-50. I do not recall. Maybe I'll swing by the store tonight on my way home and return it and buy different stuff.

Bladecutter · 10-28-2009, 09:06 AM

Quote:

Originally Posted by Brucelee

I am not aware of anyone making a 10W-50 oil. I think M1 only comes in 15W-50. That seems a bit heavy, even for SD, which can get quite chilly at nightime.

I would stick with the 0W-40, esp in winter.

Good luck.

Wow.
How cold does San Diego get at night?

M1 15W-50 is rated at -39 C for its pour point.
Here's the Product Data Sheet:

http://www.mobil.com/USA-English/Lubes/PDS/NAUSENPVLMOMobil1_15W-50.asp

I didn't realize that San Diego got THAT cold at night.

BC.