Switched to Syn. results after 500 miles

Carl83911 · 07-05-2005, 08:47 AM

Last week I posted several topics regarding switching to synthetic oil on an older 911 particularly SC's. I received several feedback on that topic and didn't really help me decide whether to switch or not. Those for or against the switch were pretty even. So I decided Friday afternoon to go ahead and do it.

We had a weekend trip to the Northern California coast and returned home yesterday Monday. It may be too soon to report on the condition of the motor but as far as I'm concerned, there were no visible leaks or smoking using the synthetic. In fact, the car ran a bit cooler (not much but cooler). My gas mileage is better. from 23mgp to 25.2mpg on the hwy. We logged in over 500 miles this weekend driving up and down Hwy 1 in Cali.

I can say that I'm very satisfied with Mobile1 supersyn 15w/50.

jtratza · 07-05-2005, 08:57 AM

I switched a couple of years ago. Leaks didn't start for a month or so. They started slowly and are now a gusher. How many miles on the SC. I had about 140k on my 1987 when I switched. For now I'm back to dino but may revisit syn oil after a rebuild.

livi · 07-05-2005, 08:57 AM

Well, there you have it, Carl.

I have the same experience some 1500 miles since going synth with Mobil 1 0w40.

Of course, as you mentioned, perhaps we have to wait another few thousand miles before the dripping and smoking start...

livi · 07-05-2005, 09:00 AM

You REALLY had to let us know, didn´t you Tom...

jtratza · 07-05-2005, 09:08 AM

Sorry guys. But consider how clean the seals will be after the switch. Hopefully you won't see any leaks. Two of my oil return tubes are leaking but I don't think has anything to do with Mobil One. I'm hoping your's don't leak so I can switch to it later.

ricochet · 07-05-2005, 11:12 AM

I switched to Castrol synthetic 20-50 almost 1.5 years ago and still have zero leaks. If she sits 10-14 days, I will get a puff at startup, but just briefly. As far as oil consumption, I cannot say. Mine used maybe 1 quart in the last 2200 miles (is an unknown history 3.2) in my 79SC.
I'd prefer Mobil, but stayed with my mechanics recommended brand. She leaked like a sieve before Rennsport cured my leaks (when she used dino oils) but now is dry as a bone (even with synthetics). I guess each case differs.

jtratza · 07-05-2005, 11:21 AM

See guys. Another Texan weighs in and with a good experience on syn. I wasn't trying to alarm anyone just relate my misadventure. Hope all goes well down the road.

Carl83911 · 07-05-2005, 12:13 PM

Quote:

Originally posted by jtratza
I switched a couple of years ago. Leaks didn't start for a month or so. They started slowly and are now a gusher. How many miles on the SC. I had about 140k on my 1987 when I switched. For now I'm back to dino but may revisit syn oil after a rebuild.

90K

MobileWrks · 07-05-2005, 02:25 PM

Glad to see the trip went well. How about the other cars in the group do?? How many total? WHERE ARE THE PIX!!!!!!!!!!

Carl83911 · 07-05-2005, 02:42 PM

Quote:

Originally posted by MobileWrks
Glad to see the trip went well. How about the other cars in the group do?? How many total? WHERE ARE THE PIX!!!!!!!!!!

____

Hey Jimmy,

All the cars ran well. We had a blast driving the twisties. We took many pics which I will post as soon as I receive copies from the guys. Matt and I had a little fender bender(not quite) just bumped bumpers. Split his rear and tore my front rubber bumper. other than that, everything was cool (literally) 65F all weekend.

The pics came out great.

island911 · 07-05-2005, 04:29 PM

Switched about 5 years ago.

. . .and today, working back by the oil cooler, I think I spot an oil leak!

That's it; I'm blaming the M1.

Apparently it takes 5 years for M1 to cause leaks.

patkeefe · 07-05-2005, 04:39 PM

Mine leaks like a seive, so maybe I'll fill it with synthetic and see if it stops. Now that I have this new Craftsman power washer and 3 gallons of Simple Green, I can clean it up before tech inspection and check the leak rates.

I'll add some STP for good measure.

ricochet · 07-05-2005, 06:12 PM

Quote:

Originally posted by patkeefe
Mine leaks like a seive, so maybe I'll fill it with synthetic and see if it stops. Now that I have this new Craftsman power washer and 3 gallons of Simple Green, I can clean it up before tech inspection and check the leak rates.

I'll add some STP for good measure.

Hey Pat,

If she leaks now, I'll bet that leak get's worse with ANY synthetic oil. I am FAR from any advisor, BUT I'd bet a small leak will indeed get worse with most synthetics. I have read stuff from Lubemaster and his info is few synthetics improve seals. Most we see may make seals show no improvement, maybe show decrease.
From my limitead readings, most synthetics may increase leakage, no improvement. I'd love to be proved wrong, but a tight engine may love synthetics. Most lose engines may show less than than love for synthetics. Is just my opinion, YMMV.

randywebb · 07-05-2005, 07:51 PM

Somebody should check all the posts re leaks for 1. the age of the engine; 2. whether a MG or AL case; and 3. if they rebuilt the engine and replaced all the seals -- and how long ago.

That's the only way to get to the bottom of this.

AFJuvat · 07-05-2005, 08:07 PM

What I've always found is that if you have a small leak with dino juice - the lind of leak that seeps and sludges up, synthetic will disolve the sludge and make the leak seem much worse.

AFJuvat

RoninLB · 07-05-2005, 08:33 PM

LubeMaster is the final word on oils. It's almost like he put to rest any question in the world on lubes. Pick a search word and LubeMaster77 and enough condensed info pops up to fill a library.

I don't think he ever mentioned running brake fluid in place of motor oil to swell seals though ?

M.D. Holloway · 07-05-2005, 10:22 PM

RoninLB - you are a kind and thoughtful man! Thanks for those words.

Running brake fluid in place of motor oil to swell seals? Thats an ol timers trick - they used to rub the seals with a lil fluid prior to mating them. The fluid will actually swell the seals but too much will cause them to loose there tensile strength. I really would strongly suggest not running brake fluid in place of engine oil or even getting it on the seals. The varnish that will build up very quickly will ruin rings, liners and bearings. Then again, I have seen some guys put good gear oil added to the engine oil. Scary but they say it works great. Some good gear oils will have seal swelling agents and even shear resistant adhesive / cohesive polymers that allow the oil to "climb" (you guys have seen the demo in Pep Boys I am sure). I have some of the gear oil additves but I have not developed the sack to try this on the 2.7 - she has found her juice and I don't want her to taste another!

Older engines (pre 80's) had questionable seal technology - the polymers they used just were not as good as some of the stuff that came out later. If you have an older engine with new seals then you may survive. The original seals if nothing else will start to go south regardless of the oil. Thats a lot to ask of a seal - 30+ years and no leaks! Heck, I can't even claim that...

I just got the results back on my 500 miles oil analysis with my special brew. I am happy to say that prior I was using Mobil 1, I had increased levels of various wear metals as well as premature oxidation and signs that acids were forming. With the new stuff (which is a stout synthetic blend), not only does the engine run about 20 degs cooler under the same conditions, but my wear metals are very low and no signs of oxidation or acid formation. The viscosity is still perfect as well. I know it is only 500 miles. The real test will be after 7000! I have not noticed any increase in leaks but ther has not been a decrease either.

I got my Volvo to 42,000 with it before I changed oil - who knows...

CharlesJones · 07-06-2005, 01:59 AM

Hi LubeMaster. It sounds like you really know a lot about oils. Do you deal in them or something? One thing I just want to clarify though - when you say:

Quote:

I am happy to say that prior I was using Mobil 1, I had increased levels of various wear metals as well as premature oxidation and signs that acids were forming. With the new stuff (which is a stout synthetic blend), not only does the engine run about 20 degs cooler under the same conditions, but my wear metals are very low and no signs of oxidation or acid formation.

do you mean that you were using Mobil 1 (when you had signs of oxidation etc) but are now using a stout synthetic blend, or do you mean that you were using some other oil prior to using Mobil 1, and that now the stout synthetic blend you are using is the Mobil 1?

Sorry I sound a nunkhead asking for clarification - its just that I'm in England and I think sometimes things get lost in translation slightly (subtle differences in language)! I just want to make sure I'm reading you correctly because I value your advice.

Thanks.

M.D. Holloway · 07-06-2005, 09:16 AM

Actually, I direct reliability - mostly various factories and heavy construction equipment. Lubrication is only one slice of the pie (albeit an important one).

The engine had Mobil 1 in it - I changed it out. Don't get me wrong, the Mobil 1 is good oil from a fuel company, but it is more hype than performance. It is still a pretty good oil - most likely the best you can get at Walmart, Autozone or Pep Boys if that is where you wish to buy the most important fluid in you car save your own bodily fluids!

movin · 07-06-2005, 11:18 AM

Hi LubeMaster77,
What are you using for engine oil? Wow, if we can't by a good engine oil at WalMart or autoparts suppliers were else?
I've reviewed the spec's off most manufactures websites and found mobil1 to very good, spec wise. So you're saying spec's aren't everything? I agree but it's an indication of were to start. What do you recommend for the P cars? I'm using shell synthetic Rotella 5W-40 right now, I don't believe it's a genuine synthetic.