Quote
imtonyd
As I live in Southern Ontario Canada I store my 07 Boxster during the winter months. For the past 3 years, immediately after the initial engine start in the spring, oil leaks from the Rear Main engine seal. This is an expensive repair that I do not wish to have done every year. I believe that because the engine is not being run for 3-4 months the RMS is dry and without lubrication. Thus at startup the torque from the crankshaft tears the seal. The engine oil is changed before storage and I was wondering if there is an additive could be added to the oil that would prevent this RMS from drying up.
My service shop has suggested starting the engine regularly while it is storage.
Looking for a solution.
Thank you in advance for any suggestions
Lack of use can have the seal shrink. But this takes longer than a few months However, the effect is accumulative.
Believe it or not the oil already has additives in it to prevent seal shrinkage. The problem is during storage the engine is not run and the seals do not get washed with oil.
The shop's advice to run the engine once in a while is good advice. Start the engine and let it idle a while then raise RPMs to 1500 and hold for a bit then let the engine speed return to idle. You want to ensure engine oil gets slung about and washes every interior surface wtih fresh oil to ensure all seals and what have you are bathed with oil. The fuel system gets used too of course and fuel gets stirred in the tank by the fuel pump (this stiring is a by product of the design of the pump/housing which has part of the pump's output directed to causes fuel to flow over/around the fuel pump for cooling; a side effect is this immediately addresses any stratifcation the fuel might have developed from sitting.) The stale fuel in the fuel lines and injectors get flushed out and this helps keep the fuel system working right.
Ideally you'd like to let the engine idle long enough for the T-Stat to open so coolant circulates. This helps prolong the life of the hoses and other components in the cooling system.
While the engine is idling turn on the A/C and let the compressor run. This circulates refrigerant and compressor oil through the system and helps keep the A/C seals/o-rings pressure and fluid tight.
With fresh oil the engine starts out with no water in the oil. The bit of running may introduce some water into the oil but it will be minimal. And if you let the engine idle long enough that the oil gets "hot" because the crankcase ventilatiom system will have the crankcase at less than atmospheric pressure the boiling point of water (and any unburned fuel in the oil) will likely boil and be removed so there will be minimal build up of these contaminants over the winter season.
Come the return of the driving season a nice long drive that has the engine up to temperature -- the radiator fans running on their own is a good sign the engine is "hot" -- will have the water and unburned gasoline removed. Then come the start of winter you change the oil and repeat the process.
Regarding the actual oil leak Pedro asks the right question. A few drops then no more is not a real problem. 'course, if everytime you park the car a few drops appear under the car then that's a "problem".
When the RMS is replaced the new one must be handled with care. It must be installed squarely and surely the shop knows this. What it might not know is the new seal should *not* be installed at the same postion as the old one. The old one can have worn a shallow depression/groove around the crank journal and if the new seal is installed in the same place because of this shallow depression/groove the new seal doesn't well seal as well and leakage can occur.
The seal should not leak with 0w-40 oil. When my Boxster's RMS was replaced at 25K miles -- under warranty -- the engine had 0w-40 oil. After the seal was replaced there was no leakage. And the seal has remained oil tight for over 290K miles most of these miles covered with 0w-40 oil in the engine. Only in the last year or two did I switch to 5w-50 oil but not out of any concern for oil seals simply because of the very high ambient temperatures here in the summer coupled with the very mild winter temperatures that don't even get close to the point 0w-40 oil should be used.
Bottom line is if the RMS leaks frequently and you want this addressed a new seal is required. But it is important that as I covered above the new seal be replaced correctly and the new seal's installed depth be considered to avoid installing the new seal at the same spot as one of the previous seals.
After the new RMS is installed consider running the engine regularly during the winter to help the RMS and other seals/gaskets/etc better avoid the effects of lack of regular use during the winter.