MAC Posted March 18, 2008 Report Share Posted March 18, 2008 From what I've read new synthetic oil is better than it use to be at sealing. I also remember somebody mention that synthetic helped stop oil leaking. I know that some complain that synthetic causes more leaking but I think I'll find out for myself. I bought SuperTech, Higher Mileage Formula, at Wal-Mart for $15/5 gal. Two gallons and I have some to spare along with an ACDelco filter. I'll post the results. Link to comment Share on other sites More sharing options...
WarrenJ Posted March 18, 2008 Report Share Posted March 18, 2008 I bought SuperTech, Higher Mileage Formula, at Wal-Mart for $15/5 gal. Two gallons and I have some to spare along with an ACDelco filter. I'll post the results. The "high mileage" part suggests to me your new oil has some additives not generally present in "regular" oil. I'm left to wonder whether the "high mileage additives" are more important to you than the "synthetic" part. 58,000 miles on the "green one;" 78,000 on the "black one." Am I "high mileage?" Nah, I think not. Regards, Warren EDIT: Don't forget to come back to us and let us know how you made out. There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises Link to comment Share on other sites More sharing options...
MAC Posted March 18, 2008 Author Report Share Posted March 18, 2008 I bought SuperTech, Higher Mileage Formula, at Wal-Mart for $15/5 gal. Two gallons and I have some to spare along with an ACDelco filter. I'll post the results. The "high mileage" part suggests to me your new oil has some additives not generally present in "regular" oil. I'm left to wonder whether the "high mileage additives" are more important to you than the "synthetic" part. 58,000 miles on the "green one;" 78,000 on the "black one." Am I "high mileage?" Nah, I think not. Regards, Warren EDIT: Don't forget to come back to us and let us know how you made out. Actually, I'm more interested in trying synthetic to see if it helps seal the pan and whatever else is leaking. But I don't mind the Higher Mileage Formula because my Eldorado has 104K miles on it. Here is some information about SuperTech oil. Here is what one poster said: i like st [superTech] oil...it is api certified and also GM 6094m certified, which are high standards...their synthetic and regular oil are great bargains...oil filters are excellent too...main thing for any oil is the the API certification....turbos need synthetic by the way for the extra heat...by the way, not all oils met the GM standards, you can see who didnt make the somewhere on the internet...use ST w/ confidence but dont abuse your engine and check the oil once in a while...7500 mile oil changes are fine for most cars according to consumer reports...even higher for synthetic, 10000 minimum...but change filter and a new quart if you go higher than that...api certified oil is a great product Link to comment Share on other sites More sharing options...
PAUL T Posted March 18, 2008 Report Share Posted March 18, 2008 I started using 10W40 in my 94 Concours with 168,000 miles and it seemed to slow my oil leakage alot. I could not see paying the higher price for the high mileage formula. Link to comment Share on other sites More sharing options...
MAC Posted March 18, 2008 Author Report Share Posted March 18, 2008 I started using 10W40 in my 94 Concours with 168,000 miles and it seemed to slow my oil leakage alot. I could not see paying the higher price for the high mileage formula. How long did it take before you saw oil leakage slow? I'll report back in a week with the results regarding any change in oil leaking. When I changed oil yesterday I inspected the oil pan and surrounding area, so I'll be able to make a determination if these areas look any drier since the change to synthetic. Link to comment Share on other sites More sharing options...
abad95 Posted March 19, 2008 Report Share Posted March 19, 2008 I have 198000 miles on my '95 STS and that's all I've been using,and it did slow down my oil pan super small leaks. You can't beat Supertech for the money. My miles will prove that.(And of course maintanance). Florin Link to comment Share on other sites More sharing options...
MAC Posted March 20, 2008 Author Report Share Posted March 20, 2008 I have 198000 miles on my '95 STS and that's all I've been using,and it did slow down my oil pan super small leaks. You can't beat Supertech for the money. My miles will prove that.(And of course maintanance). Florin I didn't know SuperTech Full Synthetic has such a fan base until I started doing some research. It's a group 3 hydrocracked petroluem product. It seems to be a mystery as to exactly who makes SuperTech. Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 20, 2008 Report Share Posted March 20, 2008 MAC I assume this is a 10W30? I have been using Rotella 15W40, due to low oil pressure at idle that I attribute to bad case half seals. Here is a photo of the case half, you can see the oil galleys, there is a seal between the case halfs at this oil galley. I believe that the seal not only can leak externally were we see oil leakage/loss/smoke but it can leak internally at this oil galley lowering the oil pressure at idle and probably overall but it becomes critical at idle. I began to surmise that this was happening because we had a member who went to the dealer for low oil pressure and he was told it was the case half seals, and we all initiatially laughed about it, thinking that was another dealer exaggeration. Then, I studied photos of the case half and realized that the seals could leak internally. I believe that they shrink. I have heard that some oils have more seal conditioner in them, but don't know if that is true. When I did my major job last summer, my engine sat for a month with no coolant, oil or tranny fluid in it. When I started it up, I had low oil pressure for about 2 days then it got better, but it never really corrected till I started using 15W40, I need case half seals.. Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 20, 2008 Report Share Posted March 20, 2008 What do others think of my theory that the oil galley seals can leak internally lowering the oil pressure at idle so that the oil light OFF threshold is not met causing the oil light to come on. I don't think that anyone has comment on this idea, and I have put it out there a couple of times. This was happening with 10W30 for me. Now that I use 15W40, I don't see the light anymore. However, I have a feeling that IF I went back to 10W30, I would have a presistent oil light at idle what do you all think? How about this thought, say I had GOOD but borderline seals, the engine calls for 10W30, and I THINK I am doing good and I put 10W40 or even worse I run with 20W50 in it, thereby RAISING the oil pressure and putting too much pressure on the oil galley case half seals and 'blow' them, does anyone think that it is possible to blow the case half seals with high viscosity oil? One more wild thought, I know that the crank cap bolts don't exist in a corrosive environment but does anyone think that an engine could run with a crank bolt pulled. Would it just knock? Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
WarrenJ Posted March 20, 2008 Report Share Posted March 20, 2008 What do others think of my theory that the oil galley seals can leak internally lowering the oil pressure at idle so that the oil light OFF threshold is not met causing the oil light to come on. I don't think that anyone has comment on this idea, and I have put it out there a couple of times. This was happening with 10W30 for me. Now that I use 15W40, I don't see the light anymore. However, I have a feeling that IF I went back to 10W30, I would have a presistent oil light at idle what do you all think? How about this thought, say I had GOOD but borderline seals, the engine calls for 10W30, and I THINK I am doing good and I put 10W40 or even worse I run with 20W50 in it, thereby RAISING the oil pressure and putting too much pressure on the oil galley case half seals and 'blow' them, does anyone think that it is possible to blow the case half seals with high viscosity oil? One more wild thought, I know that the crank cap bolts don't exist in a corrosive environment but does anyone think that an engine could run with a crank bolt pulled. Would it just knock? A lot of questions there Mike. I wish I had some answers, but sadly nay. As for your "feeling" that a return to 10W30 would result in a persistent oil light . . . only ONE person using only ONE method might answer that question. If you'd care to experiment, I'm sure I'd not be the only one interested in the outcome. As always . . . Regards, Warren There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises Link to comment Share on other sites More sharing options...
KHE Posted March 20, 2008 Report Share Posted March 20, 2008 What do others think of my theory that the oil galley seals can leak internally lowering the oil pressure at idle so that the oil light OFF threshold is not met causing the oil light to come on. I don't think that anyone has comment on this idea, and I have put it out there a couple of times. This was happening with 10W30 for me. Now that I use 15W40, I don't see the light anymore. However, I have a feeling that IF I went back to 10W30, I would have a presistent oil light at idle what do you all think? How about this thought, say I had GOOD but borderline seals, the engine calls for 10W30, and I THINK I am doing good and I put 10W40 or even worse I run with 20W50 in it, thereby RAISING the oil pressure and putting too much pressure on the oil galley case half seals and 'blow' them, does anyone think that it is possible to blow the case half seals with high viscosity oil? One more wild thought, I know that the crank cap bolts don't exist in a corrosive environment but does anyone think that an engine could run with a crank bolt pulled. Would it just knock? You might have low oil pressure if you returned to 10W30 but I would NEVER put 20W50 in there... the bearing clearances are such that you might not get adequate lubrication and then you'd be looking at catastrophic engine damage. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
Texas Jim Posted March 20, 2008 Report Share Posted March 20, 2008 What do others think of my theory that the oil galley seals can leak internally lowering the oil pressure at idle so that the oil light OFF threshold is not met causing the oil light to come on. I don't think that anyone has comment on this idea, and I have put it out there a couple of times. This was happening with 10W30 for me. Now that I use 15W40, I don't see the light anymore. However, I have a feeling that IF I went back to 10W30, I would have a presistent oil light at idle what do you all think? How about this thought, say I had GOOD but borderline seals, the engine calls for 10W30, and I THINK I am doing good and I put 10W40 or even worse I run with 20W50 in it, thereby RAISING the oil pressure and putting too much pressure on the oil galley case half seals and 'blow' them, does anyone think that it is possible to blow the case half seals with high viscosity oil? One more wild thought, I know that the crank cap bolts don't exist in a corrosive environment but does anyone think that an engine could run with a crank bolt pulled. Would it just knock? Like you... my FEELING is that if you went back to 10W30, you would get the oil light again. I am not a mechanical engineer... I work in IT... but I see no reason that the seals... IF they are leaking internally... would not reduce oil pressure. Leak equals less pressure. If it were mine, I would have no problem running 10W40, but if I needed anything more than that... I would be looking to fix it right or get rid of it as soon as possible. The only reason I would put 20W50 in it would be to drive it CAREFULLY to wherever I was trading it in. As far as the crank bolt... there are 5 mains with 10 bolts. This is just my FEELING again but, if one bolt broke it could probably go for a little while (if you babied it...not much over a fast idle) with just a real bad knock, but not for long. Then it would break the crank. There is a LOT of stress on the crank which is why there is a main between each set of two rods. I have broken the crank a couple of times in high performance cars and my brother broke one in a GM 350 Diesel. Which was definatly NOT high performance. Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 20, 2008 Report Share Posted March 20, 2008 You might have low oil pressure if you returned to 10W30 but I would NEVER put 20W50 in there... the bearing clearances are such that you might not get adequate lubrication and then you'd be looking at catastrophic engine damage. Oh I know Kevin, I was just using 20W50 as an example of a heavy weight oil that someone might use. I have been thinking about the potential of damaging the seals by raising the oil pressure by using a high viscosity oil. Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 20, 2008 Report Share Posted March 20, 2008 A lot of questions there Mike. I wish I had some answers, but sadly nay. As for your "feeling" that a return to 10W30 would result in a persistent oil light . . . only ONE person using only ONE method might answer that question. If you'd care to experiment, I'm sure I'd not be the only one interested in the outcome. As always . . . Regards, Warren True, the only way for me to determine that is to put 10W30 in, and I might just do that this week to test this theory Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 20, 2008 Report Share Posted March 20, 2008 What do others think of my theory that the oil galley seals can leak internally lowering the oil pressure at idle so that the oil light OFF threshold is not met causing the oil light to come on. I don't think that anyone has comment on this idea, and I have put it out there a couple of times. This was happening with 10W30 for me. Now that I use 15W40, I don't see the light anymore. However, I have a feeling that IF I went back to 10W30, I would have a presistent oil light at idle what do you all think? How about this thought, say I had GOOD but borderline seals, the engine calls for 10W30, and I THINK I am doing good and I put 10W40 or even worse I run with 20W50 in it, thereby RAISING the oil pressure and putting too much pressure on the oil galley case half seals and 'blow' them, does anyone think that it is possible to blow the case half seals with high viscosity oil? One more wild thought, I know that the crank cap bolts don't exist in a corrosive environment but does anyone think that an engine could run with a crank bolt pulled. Would it just knock? Like you... my FEELING is that if you went back to 10W30, you would get the oil light again. I am not a mechanical engineer... I work in IT... but I see no reason that the seals... IF they are leaking internally... would not reduce oil pressure. Leak equals less pressure. If it were mine, I would have no problem running 10W40, but if I needed anything more than that... I would be looking to fix it right or get rid of it as soon as possible. The only reason I would put 20W50 in it would be to drive it CAREFULLY to wherever I was trading it in. As far as the crank bolt... there are 5 mains with 10 bolts. This is just my FEELING again but, if one bolt broke it could probably go for a little while (if you babied it...not much over a fast idle) with just a real bad knock, but not for long. Then it would break the crank. There is a LOT of stress on the crank which is why there is a main between each set of two rods. I have broken the crank a couple of times in high performance cars and my brother broke one in a GM 350 Diesel. Which was definatly NOT high performance. Thanks Jim for your impressions. I don't think I ever heard of a crank breaking wow. I don't plan to use 20W50, I was just using that vicosity as an example of an oil you might use to raise the oil pressure that MIGHT damage the case half seals if they were borderline bad. Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
MAC Posted March 20, 2008 Author Report Share Posted March 20, 2008 MAC I assume this is a 10W30? I have been using Rotella 15W40, due to low oil pressure at idle that I attribute to bad case half seals. Here is a photo of the case half, you can see the oil galleys, there is a seal between the case halfs at this oil galley. I believe that the seal not only can leak externally were we see oil leakage/loss/smoke but it can leak internally at this oil galley lowering the oil pressure at idle and probably overall but it becomes critical at idle. I began to surmise that this was happening because we had a member who went to the dealer for low oil pressure and he was told it was the case half seals, and we all initiatially laughed about it, thinking that was another dealer exaggeration. Then, I studied photos of the case half and realized that the seals could leak internally. I believe that they shrink. I have heard that some oils have more seal conditioner in them, but don't know if that is true. When I did my major job last summer, my engine sat for a month with no coolant, oil or tranny fluid in it. When I started it up, I had low oil pressure for about 2 days then it got better, but it never really corrected till I started using 15W40, I need case half seals.. Yes, the SuperTech is 10W-30. In my non-expert opinion it certainly seems plausable that a leaking case half seal could lower oil pressure. If it leaks at a number of places I would think it could create a low pressur problem at idle. Also, since oil pressure increases as RPMs increase, I would think there could be a critical loss of oil pressure in general accross the board since the more pressure, the more likely the leaking will increase. I'm not an expert so I would imagine that sufficient pressure build up could lessen leaking by creating surface tension, but I would think this would only be a factor if the leaking is minor. Link to comment Share on other sites More sharing options...
jking220 Posted March 20, 2008 Report Share Posted March 20, 2008 Mike, I think you are right that an internal half seal leak would drop your oil pressure. I also agree that running a higher viscosity oil would raise your pressure, and if your seals are bad enough, you could of course blow your seals. JMO Jonah Link to comment Share on other sites More sharing options...
PAUL T Posted March 21, 2008 Report Share Posted March 21, 2008 I started using 10W40 in my 94 Concours with 168,000 miles and it seemed to slow my oil leakage alot. I could not see paying the higher price for the high mileage formula. How long did it take before you saw oil leakage slow? I'll report back in a week with the results regarding any change in oil leaking. When I changed oil yesterday I inspected the oil pan and surrounding area, so I'll be able to make a determination if these areas look any drier since the change to synthetic. I noticed it within the first couple of weeks. I am not sure to what extent the difference is though yet. Link to comment Share on other sites More sharing options...
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