peavynation

I've done some searches on short drive times and what effect it has on an engine, but want to revisit it (lot of replies by people in other threads saying how LONG their commutes are, without adding any helpful info on the topic at hand!)

I moved to a house that is 1.9 miles from the office. I may bike or walk some of the time, but there's a Hemalian-esque hill between here and there. Plus I like drive the Pcar.

Concern: Water accumulating in the oil.
Will one drive per week longer than 15 minutes keep the water content at bay?
Will a few spirited high-RPM sprints help to burn off the water or have no affect at all? (with engine oil at proper temp, of course).
Should the oil be changed sooner, say in 6 months, regardless of miles put on?

Concern: Spark plugs
Will switching to a "hotter" plug be of any benefit?
What detriments (if any) to standard plugs will there be with short drive times?

Any other input/info from folks out there? (other than "I drive a million miles a day both ways, yada yada yada...") And I DO feel for you guys with long commutes: For 5 years I did a 150 mile commute, with 1/4 of it in stop and go traffic. I paid my long-distance dues.

And as for "cold starts", we all have the same number of cold starts regardless of how long our commutes are: two of them. The issue is the engine oil not getting to proper temp during the drive, not the cold starts.

roadsession

My dealer tech who is dealing with my dead engine replacement said that there is a phenomenon he calls the "Boston / SF / NYC" syndrome - that's where the owners live <5 miles from where they work - and they're just prone to a lot of problems with the engine because the design parameters of the Porsche was not really well suited to that type of driving style.

I live 2.5 miles from work and I drove my P car everyday too - rain or snow or shine. I'm not saying that's the cause of it, but I don't think it helped with my IMS bearing disintegrating and damaging my engine. I changed the oil every 6 months too - but I bought used so who knows what the previous owner did the previous 30K miles - but I bought a 6 year old car that had about 30k miles, so that previous owner drove the car around 5k miles a year - which means he either had it as a garage queen or had an extremely short commute like mine.

With my new engine I am going to try something a little different. I am still going to do my short commute to work, but ONCE a week I will take a 10 mile drive on the highway and bring it up to operating temp. I will also change the oil every 4 months - not 6. In any case Porsche warranties the new engine for 2 years or 100K miles

Macster

15 minute drive is not much time. Depending upon ambient air temperature and the type of driving the engine may not be quite as hot as you might think. And high rpms under these conditions will just be slinging about alot of cool oil.

As an aside: Back in '02 I lived in the mid-west (KC MO area) and bought a new 02 Boxster in January of 02. I drove the car 2K or 4K miles (I forget now how many miles) back and forth to work (10 mile one way commute with speeds from 25mph to 45mph) and with longer runs (40 or 80 or even 150 miles once in a while) and on a whim had the oil analyzed. The water content was around 7%, or nearly a half a quart of water in 9 quarts of oil. And I thought *I* was driving the car enough to boil out the water. Curious, I started using an OBD code reader/data viewer to monitor coolant temp in real time and found the coolant temp would barely seldom get to 196F and even then this took some slow speed driving in traffic. On the highway? Forget it.

Also, if you run with the A/C on this works to keep the engine oil cooler than it would be otherwise because the A/C fans run all the time and help pull cooling air through the radiartors. It is heat that drives (boils) the water out of the oil. Heat helped by the pressure difference between the crankcase's pressure (low) and atmospheric air pressure. In short the low pressure created in the crankcase by the AOS lowers the boiling point of the water in the oil.

Leave the plugs alone. They'll be fine.

Just once in a while take the car out for a longish drive. 30 minutes or so. It doesn't have to be a high speed drive -- in fact the engine will warm up quicker and get hotter puttering around town -- and with the A/C off. Ideally you would want to drive the car long enough to get it hot enough you hear/feel the radiator fans come on at least a few times. They come on (low speed) IIRC at 212F and shut off at 205F.

I might add even though I drive my cars during the week mainly using them to commute about 60 miles (round trip commute) both the Boxster and the Turbo really perk up after a 50 to 80 mile or so drive at highway speeds. Say 40 miles down the freeway then make a turn around and come back.

And I would certainly consider changing the oil at least every 5K miles under these conditions.

This is about all you can do.

Sincerely,

Macster.

Awesomo996

There is a procedure we use in general aviation where after each flight remove the oil filler cap. I always see steam coming out the filler even after long flights. It doesn't get all the water but it releases the extra water vaper before it can condense on the metal parts of the upper engine. I'm lucky that I've got a 9 mile commute in the pcar, but I still find a little brown milky residue in the oil filler neck indicating some water in the oil.

Removing the filler cap still requires that, as Macster says, the oil needs to get to a temperature high enough to boil the water out of the oil, but even if a little steam can be seen escaping that is water vaper which is not in your engine any more. I also have one friend who takes a small shop vac to his oil filler after each flight in his Super Cub, I'm sure it helps eliminate the vaper but I wonder what he is doing to his engine seals with the suction.

peavynation

Guys, thanks for all that really great info. I like all your real-world experiences mixed with bits of quantitative data (7% water! Yikes! Thanks for that data point Macster, I never would have guessed it!).

I like the long drive once a week idea, coupled with removing the oil filler cap for a bit after the drive.

I would like to think that short drives do NOT contribute to engine failure issues with these cars, so I'll just continue to think that, drive the car, and enjoy every minute of it.

ivangene

well I didnt read all that and I am sure its good info - I will just add my experience

my old job was only about 5 miles from home and between home and work i would make 3 stops daily - one at school, one at my mother-in-laws and one at the post office... after about 3000 miles I went to change the oil and it looked pretty dirty, but smelled really wierd - skunky...anyhow, filled it with oil and pulled the dip stick to check the level and the entire dipstick was rusted BAD!! i couldnt figure out why that would happen and started doing some research.. thats when I found out how much water a motor can accumulate on short trips where it doesnt get hot enough to cause the water to vaporize....

you either have to burn the water out or change the oil every 1000 miles if you have a short commute - that part is a guess, but you get what I am saying....

fpb111

Put a 100 watt light under the pan to preheat the oil and drive moisture out, should get warm enough to evap some H2o.

I had a Jag XKE that was a bit_h to start in the winter. It lived in an open carport at the time.

I made an insulated open top tin box with a 100 watt light in it that fit under the oil pan. I parked the car facing out and ran the wire on the ground down the middle of the car from the rear.
I would turn the light off as I walked out in the morning and start a warmed engine (added bonus was quick heat) and drive off. At night it was the reverse. I just backed over the light and turned it on as I went in the door.
Downside was the field mice loved it.

larry47us

How long you drive your car is irrelevant. How high the engine temperature gets IS relevant. You want to drive the car till you reach operating temperature (over 180) and then you can flog it a bit. It will be an enjoyable run, and I would think that you would want to do it once a week. That would likely boil off the moisture in the oil. (not scientific finding, just my thoughts.)

BTW, take your time warming up your car. Don't warm it up idling in the driveway, just drive it gently up to 4,000 RPM until the engine is fully warmed. Then get to a stoplight, and run that puppy to redline a couple of times. You'll feel better having your PCar, and the car will love you back (by lasting longer and running better between service calls.)

But I think that Ivangene has the right idea. With short hops like you have, I would suggest that you increase the frequency of your oil changes. It has been reported (by people much more technically oriented than me) that it is infrequent oil changes, with the resulting buildup of acid in the oil that eats away at the grease and eventually at the bearings in the IMS - leading to premature failure. Even though your new engine has a 2 year warranty, unless you are planning on selling it at the end of two years without a conscience, you'll want to take care of the engine. Just my 2 cents. It's your car.

larry

chsu74

I moved my office to about 1 mile from where I live two years ago and faced the same issue. I ended up making an effort to drive my cars for 20-30 minutes after work to run them a bit but really don't care about the cars when getting to the office in the morning.

peavynation

Ed, thanks for relaying that experience. That's exactly what I'm afraid of!

Thanks for all the input from everyone else too. Actually, I was thinking about a pan heater. I like the idea of the bulb-in-box since it can be stationary and I can drive over it without too much hassle. Cool.

I was also thinking about something more crazy too: an oil-water cracking system! Lol! I would just empty my oil once a month into this little honey of a contraption I have yet to design, let it run thru the oil to separate/boil-off all the water, then filler back up. Being an engineer, I like to make things as complicated as possible.

And what's wrong with letting your car idle for awhile? I've always heard that fleet vehicles that are idling more often than driving have more issues with their timing belts/chains. Why would this be? I always let my car idle until the primary (secondary??) air pump shuts off, as Macster does. This is of course not an issue, but what if it idled for 5 or 10 minutes or longer each morning? Bad? Why?

Malakas

My office was certainly less than 5 miles from my house, and I drove the 4S as a DD for 2 years... no issues aside from routine maintainence. Of course, I never left the driveway until the idle settled down, and it was usually up to operating temperature about 1/2 way through the drive. I used that same car for DEs and besides needing new plugs and and 3 cracked coil packs - it was very reliable.

Now the car sits in the garage for DEs or a weekend cruise. I worry about that more than when it was a DD.

No HTwo O

Peavynation, here is a good thread about the ill effects related to short drives:

https://rennlist.com/forums/924-931-...-analysis.html

Do you do UOA's?

rpm's S2

Two thoughts seem rather obvious on this quesiton:

1. Ensure that you allow the car to warm up for a minute or two before leaving home or work.

2. Find a long and twisty road around the mountain!

Chaos

+1 on a long warm up and stop by the girl friends on the way in or the way home.

peavynation

Haa! Well, the girlfriend is actually the wife, and she's at home so it's a one-stop shop for all of that. I like the idea of taking it thru the twisties, but unfortunately it's straight up the mountain in a line, and a 4x4 needed to get round it (but I DO have a C4! )

No HTwo O - I haven't done any UOA's on this car (or any car that had short trips on it's odo), but I plan to for sure. BTW, your name is very fitting for this discussion.