'82 porsche, ok for syns?

[bighitr]

Called the Dealer about my 3.1 ltr. with 96K mi. Burns maybe 3/4 qt. over 4k mi. But runs hot here in Ca. over summer. Asked if I could go to syns, and replied no..because the seals in older Porsche' are not suited for this use. Knowledgeable friend (so he says) disagrees. I'd like this thing to run cooler...any oils that will help w/ this potential seal prob? Dealer said to run Castrol GTX 20-50. Thanks

 

[Bob Woods]

In 1979 I bought a new 79 camper bus with 2 liter pancake motor, the same engine used in the 914, the VW dealer told me the same thing. I used MobilOne and my oil comsumption ceased and I didn't have leak problems.

 

[TR3-2001SE]

I am of the opinion your dealer is right on. I have a TR3 with 25,000 on a new engine and would never use synthetic in it. Castrol GTX 20w-50 is what I use and belive it or not this is recomended in the original owners manual. Large clearences I would guess and old tech. seals are some of the reasons.

 

[ekpolk]

On the other hand, I suspect that the real reason manufacturers say "no synthetics" is because while some are OK, some are not, and they are trying to minimize complaints by those who might use the wrong synthetics. Unlike natural petro oils, how a synthetic interacts with the engine's seals is very dependent upon how the oil is formulated. From what I've picked up, most of the major and reputable syn producers have long ago made their oils fully seal compatible. So you would probably be fine with any of the major brands, but of course, you'd be on your own if you do have a problem, because the car maker can stand back and say, "we told you so." In short, their approach to the existence of a few bad or questionable apples is to tell you to avoid the entire bushel.

 

[Jelly]

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Originally posted by ekpolk: In short, their approach to the existence of a few bad or questionable apples is to tell you to avoid the entire bushel.

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That's a good statement, and one that I like and fully agree with. IMHO, the only problem you'll have when using a syn-lube is gonna be if the previous mineral-based oil didn't do its job. If your old seals are "glazed over" with varnish and have now hardened and dried up, switching over to a synthetic will clear away the old varnish and now the seals will be asked to do their one job in life, which they no longer can perform. Sometimes it's an issue...and sometimes it's not. Changing oil won't make temperatures drop that much (if at all), but switching to Mobil1 15w-50 will offer you much better high temperature protection in comparison to a 20w-50 PCEO. Make the switch... [ April 29, 2004, 01:49 PM: Message edited by: Jelly ]

 

[PRRPILL]

Hi, I ran it in my 79 930 Turbo for 8 years. Only put it in at 25,000 miles. No leaks. A properly formulated Synthetic, will accept the same seals as a mineral motor oil. The dealers cover themselves by saying this. If they are leaking now, they will probably leak after the change. My oil ran about 30 degrees cooler. My Turbo also stopped failing, and at $1200.00 a pop to rebuild, it was worth the change. [ April 29, 2004, 01:55 PM: Message edited by: PRRPILL ]

 

[bighitr]

Thanks for the input..I also ran a '78 Turbo and blew threw turbos like butter, afetr the second in six months I sold it. I sounds like it possible to move to a Syn...but know, which one is formulated to handle the sealing issue if there really is one. I have to believe someone has it.

 

[Dr. T]

Last year I spoke directly with a Porsche mechanic. He says all Porsches get M-1. 0-40 for the new ones (~`99 and up) and 15-50 for the older ones. He couldn't account for why other than to say that's what they were told to do. There were cases of each around. I don't think you will have any problems with using M-1 15-50.

 

[FowVay]

I'll hop on the bandwagon here and suggest M-1 15W-50 too. I have several friends with the even older 2.7 liter engines and they use the M-1 chemistry with no problems. Some of their cars are rather ratty though. My only concern would be the fact that it takes between 12 - 14 quarts of oil and that's a major investment. Don't forget about the trusty HDEO 15W-40's on the market. They may dissipate heat at a rate faster than the 20w-50's and help with your temperature problem.

 

[Cary]

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Originally posted by bighitr: Called the Dealer about my 3.1 ltr. with 96K mi. Burns maybe 3/4 qt. over 4k mi. But runs hot here in Ca. over summer. Asked if I could go to syns, and replied no..because the seals in older Porsche' are not suited for this use. Knowledgeable friend (so he says) disagrees. I'd like this thing to run cooler...any oils that will help w/ this potential seal prob? Dealer said to run Castrol GTX 20-50. Thanks

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Tell your dealer to go review Porsche's latest oil related Bulletin. This was covered in last months Ecellence magazine including a list of approved oils. The list is for all Porsche Vehicles from 1973 through 1998 and includes NO mineral oils. All approved oils are Synthetics now. FYI most of the oils are 0w-40 and 5w-40 synthetics, but 5w-50 and even 10w-60 are approved for high tempuratures. So the answer is your dealer is wrong, per the Porsche Factory. BTW, since you are in California, you could run M1 15w-50 if you wanted down to temps of about 32F. Cary

 

[Jelly]

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Originally posted by Cary: BTW, since you are in California, you could run M1 15w-50 if you wanted down to temps of about 32F. Cary

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You can run M1 15w-50 to temps much lower than 32F...

 

[Bror Jace]

I agree with Jelly about running 15W50 in all but the coldest temps in North America ... not a problem. However ... This thing's a 1982. Mineral oils have come a long way in the past 22 years. I can imagine the stealerships recommending nothing but synthetics these days but I can't see why a good, Group II+ base oil or synthetic blend wouldn't suffice for this "seasoned" Porsche ... especially if bighitr is not going to go too long between drains. Is this a weekend baby? How many miles are you going to put on this thing each year? My vote for the oil to try right off the bat? Pennzoil High Mileage Vehicle in 20W50. You get a Group II+ base, synthetic ester component and a potent additive package. It's a good, safe choice and at $2 - 2.25 per quart it's economical to use even in massive sumps. --- Bror Jace [ April 30, 2004, 03:05 PM: Message edited by: Bror Jace ]

 

[Cary]

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Originally posted by Jelly:

quote:

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Originally posted by Cary: BTW, since you are in California, you could run M1 15w-50 if you wanted down to temps of about 32F. Cary

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You can run M1 15w-50 to temps much lower than 32F...

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You can run it lower, but it really starts to get thick at about 20f. I ran it year around in Oregon and even when I went to Lake Tahoe, in a BMW. At 10F it takes about 10 seconds for the oil pressure with it, probably not the best thing for motor over the long term. Cary

 

[bighitr]

Thanks for all the info I drive about 3-4k per year. Some longer trips up to Tahoe myself, and she really runs to hot. I change the oil every 3-4k prob'ly to often for some, bht I guess I'm old school. Does the petro-based oils still break down after 6 months? I guess that would be the advantage to the syn's...more expensive on the front end but may not have to change as often.

 

[Bror Jace]

"I drive about 3-4k per year. Some longer trips up to Tahoe myself, and she really runs too hot. I change the oil every 3-4k prob'ly too often for some, but I guess I'm old school." If I had a really nice toy, I don't think I could NOT change the oil at least twice each year. With a sump of a dozen quarts, I can't imagine 3-4K would stress a good 20W50 much. I wouldn't hesitate to use it ... and then get a sample tested to be sure. How hot is too hot? Does the oil temp guage have numbers or just the vague C / H markings? "Do the petro-based oils still break down after 6 months? I guess that would be the advantage to the syn's ... more expensive on the front end but may not have to change as often." No, mineral oil will be fine for a long time just sitting there as long as it is not terribly fuel or moisture contaminated. And if that's the case, I'd be more inclined to change it out ASAP. Better to prematurely drain a $2 per quart oil than $4 per quart oil. I'd try the Pennzoil High Mileage Vehicle for 6 months and about 3,500 miles. Have a sample tested and if you don't like the results, try Mobil 1 15W50 and have THAT tested after a slightly longer interval. --- Bror Jace

 

[Bror Jace]

crap! I was sure Pennzoil offered High Mileage Vehicle oil in 20W50 ... but it's not listed on their website ... only 5W30, 10W30 and 10W40. ---- Bror Jace

 

[Audi Junkie]

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Castrol GTX 20w-50 is what I use and belive it or not this is recomended in the original owners manual

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What do you expect the manual to say? "GC"? An antique car will call for antiquated oil. I would opt for Pennzoil LL 15w-40 or Castrol GTX Hi-Mi 10w-40 or even switch to the Hi-Mi 20w-50 if desired. I am sure the 20w-50 must reformulated in the Hi-Mi version. Synthetics and 911s means taking a chance. My mechanic runs Syntec 5w-50 in his wife's '82 911...3.2L though. He has it in drums along with Castrol RX 15w-40 as bulk oil. It is an either/or decision. In a Bosch Service Center that specializes in real racing Porsche Cup cars and beater VWs (some racers too) those are the only two options. At BitOG, you can get a few more options. PS once yearly changes up to 10,000 miles seems ok with the modern oils.