aceanderson Posted September 6, 2005 Report Share Posted September 6, 2005 I am about to purchase a 1995 Cadillac Seville SLS with 100k on it that was driven by a 75 year old grandmother so obviously it is in pristine condition. I was reading on some forum I think, and it read that you were supposed to run the caddys at WOT atleast once a month to blow our the carbon and to prevent the POSSIBLE OIL LEAK that is well known from the caddy's in this year range. If anybody can tell me if this is liable info and if you have any more suggestions for me I would appreciate it. Thanks alot Link to comment Share on other sites More sharing options...
aceanderson Posted September 6, 2005 Author Report Share Posted September 6, 2005 http://cars0.ipixmedia.com/abc/cars/_CARS_...817d3/i-1_T.JPG Theres a pic of the Seville. Link to comment Share on other sites More sharing options...
OynxSTS Posted September 6, 2005 Report Share Posted September 6, 2005 WOTs while fun won't help oil leaks... They help oil consumption problems as they help burn off carbon in the combustion chamber and "free" up the rings... The more the rings float in their "groves" the better they seal and the better they seal the better you feel... So WOT WOT at every meal! Sorry about that . Easin' down the highway in a new Cadillac, I had a fine fox in front, I had three more in the back ZZTOP, I'm Bad I'm Nationwide Greg Link to comment Share on other sites More sharing options...
Scotty Posted September 6, 2005 Report Share Posted September 6, 2005 There are many advantages to occasional full throttle accelerations with a Northstar and any engine. It keeps the carbon cleaned out of the combustion chamber. This is maybe a little more important with the Northstar than some other engines due to the tight squish volumes between the piston and the cylinder head. It's designed this way to promote good in-cylinder mixture motion (good combustion) but it has the down side of providing a ready place for carbon build-up to touch the piston - causing noise. Ever heard of the Northstar "cold carbon rap" problem?? Simply put you'll hear a rythmic, piston slap-like noise when the engine is cold. Very prominent and very annoying. Cause: excessive carbon build up causing the the piston to contact the carbon on the head - causing it to rock in the bore and "slap" Much more evident when the engine is cold and the pistons haven't expanded to full diameter yet. Simplest and easiest "fix" for this: A few good WOT (wide open throttle) accelerations to clear the carbon out. That is all it takes to eliminate the problem and prevent it from re-occurring. Occasional WOT accelerations also help seat the rings to the ring lands and exercise the rings and keep them mobile and from becoming stuck in carbon in the ring lands. At high RPM and WOT the rings move around on the piston - they actually rotate on the piston and will polish away any carbon and seat themselves to the sides of the ring grooves. This is especially important on the 2000 and later Northstars which had hard anodized top ring lands on the pistons. Very hard and wear resistant - also harder to break-in and seat the rings to the sides of the ring-lands to promote the best possible seal. Many oil consumption complaints on the 2000 and later engines are related, to some extent, with the rings never seating to the sides of the ring-grooves due to lack of load as the engine was babied around forever. Even engines with rings stuck in the ring-grooves due to carbon build up can eventually be freed up with enough high RPM operation. WOTs warm up the engine thoroughly and clean out the exhaust due to temperature in the exhaust and high flow rates blasting particles, rust and such out of the system. Frequent WOT operation will not hurt the engine or the transmission. They're designed for that. The healthiest engines that I have seen at high miles are always the ones that are run the hardest. Rings are free on the pistons and sealing; no carbon buildup. The exercise that I think works best for many things is to select manual 2nd gear on an isolated stretch of expressway. This takes the transmission shifting out of the question if you are worried about hurting it. Start at 55 MPH or so and go to WOT in 2nd gear and hold it until the RPM reaches near the normal shift point - i.e. 6500 for an L37 and 6000 for an LD8. Hold the throttle wide open until the engine reaches, say, 6200 for an STS and then just let completely off the throttle. Leave the transmission in 2nd so that the engine brakes the car and creates some pretty heavy over-run conditions at high vacuum levels. Let it slow until it is about 55 or so and then go to WOT again and repeat. This exercise really loads the rings, allows variable RPM operation at WOT for several seconds continuously, creates heavy over-run which tends to unload the rings and make them move and thus exercise them in the ring grooves and it will blow-out carbon and the exhaust - all without creating a spectical of yourself and attracting the attention of cops. You can do it on most any freeway and stay within the 70-75 MPH range allowable. Once a week like this will keep the engine cleaned out and healthy and is DEFINITELY recommended for the Northstar in particular. The Northstar engine was designed/developed/validated to be run hard. It was expected that people would use the performance of the engine - which few people seem to do. The biggest single problem that many issues stem from is lack of use at full throttle by the owners. It just doesn't like to be babied around. The rings are low-tension by design for good high RPM operating characteristics and low friction/good power. They work best if "used" and kept free. In every conversation with owners I have had, once the owner started doing the WOTs and using the power of the engine they report no more carbon rap, better oil economy, no "smoke" when they do light it up (keep the exhaust cleaned out. If you notice a "cloud" at WOT then you are not doing enough WOTs...) etc... A bit of judicious use of the other end of the throttle travel is a GOOD thing... Reference: http://www.cadillacforums.com/cadillac-tech.html#full Link to comment Share on other sites More sharing options...
Scotty Posted September 6, 2005 Report Share Posted September 6, 2005 With regard to oil leaks you may find that you have better results from high mileage oils. Personally I would stay away from synthetic oil. Snug up your pan bolts, check the oil cooler lines for leaks and replace and tighten as necessary, check the oil filter and oil filter adaptor for leaks and replace seals as necessary, check cam covers for leaks and replaces seals as necessary. Typically 1 quart every 1500 miles is good. Don't top off. Link to comment Share on other sites More sharing options...
aceanderson Posted September 6, 2005 Author Report Share Posted September 6, 2005 Thanks for all the help..its greatly appreciated. That site answered alot of my questions. Although, I am a bit confused on how to do this WOT task. Is it saying to manually select 2nd gear and drive WOT until the engine would shift from 2nd to 3rd and let the engine slow the car? Or is it saying to downshift or something...hmm..By the way, which transmission would the 95 SLS have? Thanks again Link to comment Share on other sites More sharing options...
JimD Posted September 6, 2005 Report Share Posted September 6, 2005 .... The exercise that I think works best for many things is to select manual 2nd gear on an isolated stretch of expressway. This takes the transmission shifting out of the question if you are worried about hurting it. Start at 55 MPH or so and go to WOT in 2nd gear and hold it until the RPM reaches near the normal shift point - i.e. 6500 for an L37 and 6000 for an LD8. Hold the throttle wide open until the engine reaches, say, 6200 for an STS and then just let completely off the throttle. Leave the transmission in 2nd so that the engine brakes the car and creates some pretty heavy over-run conditions at high vacuum levels. Let it slow until it is about 55 or so and then go to WOT again and repeat.... You can do it on most any freeway and stay within the 70-75 MPH range allowable. Once a week like this will keep the engine cleaned out and healthy and is DEFINITELY recommended for the Northstar in particular. Reference: http://www.cadillacforums.com/cadillac-tech.html#full Memorize these words of wisdom! Jim Drive your car. Use your cell phone. CHOOSE ONE ! Link to comment Share on other sites More sharing options...
MARK 99STS Posted September 6, 2005 Report Share Posted September 6, 2005 Why wait once a month. I WOT on each and every outing. My car loves it and so do I!! MARK 99STS TURBOCHARGED Link to comment Share on other sites More sharing options...
Scotty Posted September 7, 2005 Report Share Posted September 7, 2005 The guru's instructions call for at least once a week for this procedure that is about my average, WOTs can be more often Link to comment Share on other sites More sharing options...
BMWburner Posted September 7, 2005 Report Share Posted September 7, 2005 I know the engine can take the abuse, but are you guys positive the transmission can handle being flogged in such a manner? I know it's as durable of an automatic tranny as they come, but I've always been under the impression that no automatic tranny will last too long when driven hard. Also, why no sythetic oil. Scotty, you're seldom wrong so fill me in. I happen to love synthetic oil. There isn't any parafin wax in it, so it burns cleaner, and stays fresh longer, especially in the winter. I know it won't coat or clean an older engine but I still find it to be superior oil. After switching to Mobil 1 I've burned about half as much oil in two thousand miles. I know there is nothing wrong with burning oil but it's nice to have the oil economy. Additionally, I know you don't want to overfill the sump, but when should I replenish the crankcase with some fresh oil. Everyone says to leave it pretty low, but I've also heard that the warning isn't displayed on the DIC untill like 5 to 6 quarts or so. You know you're the man so hit me back. --Ben Link to comment Share on other sites More sharing options...
Ranger Posted September 7, 2005 Report Share Posted September 7, 2005 The advice we have been given from a reliable and well respected source is yes, the 4T80E is built for it and can take it without any problems. Link to comment Share on other sites More sharing options...
JasonA Posted September 7, 2005 Report Share Posted September 7, 2005 I have the original transmission fluid in my '97. The transmission is as stout as any, and is the best FWD transmission out there, in my opinion. Search the archives for synthetic oil. It's just religion...some people believe in it, some people don't. Personally, I've been running either Valvoline or Pennzoil 10W-30 for the car's entire life (almost 150,000 miles now) and the only thing that's been replaced on the engine is the alternator and water pump. It hasn't even had a cam cover off it. 100% reliable on conventional oil. If I lived where I normally start the car in -40*F weather, I would consider synthetic. But I don't, so I use regular oil, and change it according to the DIC. And yes, around here, Scotty is the man. Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
Scotty Posted September 7, 2005 Report Share Posted September 7, 2005 Well thanks for the compliments guys but I have had good training from YOU ALL and a FEW that are SORELY missed. That said, synthetic oil is one of those topics like tires that is very passionate as Jason noted. Some here will swear by it, for the right and the wrong reasons, others like myself see it as a luxury you don't need, sort of like Sunoco 94 (ok, ok, that crack is not intended to start a firestorm but you get the idea). Some like to feel that they ONLY feed their baby the best, oil, gas, wax, etc, to me some of this feeding is overkill and un-necessary. Why? 1) My first experience with synthetic was in my 91 Seville, the number one main bearing knock was twice as loud. To me synthetic's viscosity while stated at say 10w30 is affectively less than stated, which leads to #2, 2) NS's tend to leak oil, synthetic oil tends to make that worse, that is why I suggested the high mileage oils (I think Jason likes them also). Now a lot of people will say that the increased leaking is due to synthetics ability to clean, I say so what, if you have ever disassembled an engine that has regular oil changes, they are also clean, why do I need synthetic finding every nook and cranny to leak out onto my driveway and possibly start a case half leak? 2A) I have seen some report that the low oil pressure light comes on at idle while in gear (625 RPM) with synthetic, this would seem to confirm my affective viscosity thinking. 3) If I am concerned with cold starts, I will use 5W30 in the winter, which I do. 4) The cost! What do I care if it lasts 15,000 miles, if I am going to change it on average between 5000 and 7500 based on the OLM? Isn't that a waste of money? And if I leave it in 15000 miles, do I change the oil filter at 7500? How do I now monitor the change interval with synthetic, what if I don't get the oil hot enough to burn off impurities and I leave the synthetic in TOO long? Using synthetic puts me into an unknown area in terms of changing my oil correctly. 5) I am sure that synthetic is terrific for fleet use, racing, arizona, new tightly sealed engines, but to me a good grade of 10W30 in the summer and 5W30 in the winter changed based on the OLM is adequate. As I noted, the high mileage oils seem to have reduced my oil loss/consumption. I am sure that others have opposing views, but this IMHO, Thanks, Mike PS, use the OLM! Link to comment Share on other sites More sharing options...
Oldgamer Posted September 8, 2005 Report Share Posted September 8, 2005 I just want to notice that while WOT is good for cleaning carbon and make some improvements it does big stress on engine and transaxle. I'm not saying that something going to break. But how our friend once said, some parts that are old enough could do. Yes, engines and transmissions got a lot of hours under high RPM on a plant. But we gonna remember: these engines and transmissions are new. And that means all parts are new and transmission fluid is clean. If something happens on a plant they just going to sent this engine to laboratory to see whats happened. In our case we will have huge problem. We have already some cases where owners got problems after doing WOT. Not much but happened. I'm not sure that my transmission problem related to WOT. I never did WOT before and car did run fine having 70K. I did WOT first time and 150 miles later I got transmission problem. May be it's not connected. I try to explain to myself and think that fluid wasn't exactly clear (70K, 11 years) and had some dirt. With very high RPM some dirt was sucked in and filter got clogged. Now my wallet is lighter for $2K. I blame myself for not changing transmission fluid. Possible if I did I was in a better shape now. It's like stroke: some 86 years old guy can possibly live another 10 years but suddenly decide to make exercise (run around a block). What I'm trying to say: WOT is good, but we should do that when it needed to be done, not just for fun. And if you don't see any black smoke when doing it it means it doesn't do any good/you doing it too often. jadcock, you got 150,000 miles and you didn't change transmission fluid yet? Please change fluid now, you will amazed how much dirt you'll see on a bottom. As I remember it should be changed at 100K by manual. Link to comment Share on other sites More sharing options...
Scotty Posted September 8, 2005 Report Share Posted September 8, 2005 Yes Jason, if you have not changed the tranny fluid, its a 100,000 mile maintenence item, but something tells me that you did, the tranny fluid monitor would have informed you I think, Mike Link to comment Share on other sites More sharing options...
Ranger Posted September 8, 2005 Report Share Posted September 8, 2005 Scotty, I don't think that tranny fluid monitor will ever come on unless you overheat the trans if I recall correctly. Mine didn't when I hit 100K. Link to comment Share on other sites More sharing options...
Ranger Posted September 8, 2005 Report Share Posted September 8, 2005 Scotty, I don't think that tranny fluid monitor will ever come on unless you overheat the trans if I recall correctly. Mine didn't when I hit 100K. Link to comment Share on other sites More sharing options...
Oldgamer Posted September 8, 2005 Report Share Posted September 8, 2005 Tranny fluid monitor will possibly inform if car was in hard condition towing or overheated. My transaxle fluid monitor showed 93% when transaxle got 70K. (My old PCM says 99, and when I changed it I set to 93, it didn't change after that at all). It was never overheated. But really, it's interesting to check what it says. I bet it says more than 90. Link to comment Share on other sites More sharing options...
Oldgamer Posted September 8, 2005 Report Share Posted September 8, 2005 Wow, Ranger, you are so quick! Link to comment Share on other sites More sharing options...
Ranger Posted September 8, 2005 Report Share Posted September 8, 2005 Your no slouch yourself. I think we hit the enter buttons simultaneously. Link to comment Share on other sites More sharing options...
davedog Posted September 8, 2005 Report Share Posted September 8, 2005 is WOTs still important on the 4.9 in my caddy. Procedure the same? Thanks! -dave Crystal Red Tintcoat Exterior | Shale/Brownstone Interior | 32k Link to comment Share on other sites More sharing options...
Scotty Posted September 8, 2005 Report Share Posted September 8, 2005 Ranger you are stuttering! Very interesting, while I am sure the fluid is fine from an oil analysis standpoint, after seeing the magnet full and some sludge in the filter in this thread, http://caddyinfo.ipbhost.com/index.php?showtopic=7218 I myself, feel more comfortable dropping the pan and changing the fluid if for nothing else to have a look see, and to clean the magnet, screens and to change the filter. It certainly can't hurt, why not treat the seals to some fresh fluid and get rid of some dirt that has settled in the pan Afterall, that is part of what causes problems, leaving silt/grim/fine sludge in the pan that could be sucked in further once the magnet gets full and can no longer hold any more sediment, is what causes deeper problems, OLDGAMER, didn't your tranny guy say some SCREENS were full of crap? You were at 93%? I wonder if you changed it at say, 70% would you have saved $2000? Couldn't have hurt I guess. I myself am not interested in seeing how long I can run on 12 quarts of tranny fluid, replacing the fluid is an insignificant cost. Changing the fluid and filter is a great time to replace the "reuseable" gasket to stop leaks also. Link to comment Share on other sites More sharing options...
Oldgamer Posted September 8, 2005 Report Share Posted September 8, 2005 Scotty, when I drop a pan screens were not clean, but not so dirty. The most dirty was other filter, which is placed deeper inside. But, I agree, I feel that it's much better to change fluid just in case, than to pay $2K later. Dirt is cause of most expensive problem, because it can clogg filter or something deeper. Problems with solenoids are easy fix. Link to comment Share on other sites More sharing options...
JasonA Posted September 8, 2005 Report Share Posted September 8, 2005 Regarding the transmission fluid, it's not a 100,000-mile maintenance item. In fact, the owner's manual says the fluid is good for the life of the transmission if not driven under the severe service schedule. I have a pretty easy commute (10 miles of flat road), little traffic, and no real temperature extremes. Environmental conditions like this are relatively easy on the car. Yes, 146,000 miles on the original fluid, and it's not at all brown or burnt. Of course it's not blood red anymore, but I don't expect that. As stated previous, the transmission life monitor should only appear if an overheat condition was detected. This car doesn't tow or sit in hours of bumper-to-bumper traffic, so I'm confident the fluid is still in good condition. The transmission still shifts beautifully. I follow the engine oil life monitor, and don't see any reason not to also follow the transmission oil life monitor. The transmission guys are just as smart as the engine guys I'm sure. Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
Scotty Posted September 9, 2005 Report Share Posted September 9, 2005 I just checked my maintenance book and the tranny fluid is scheduled to be changed at 50,000 and 100,000 miles if it is mainly driven in: City traffic where the outside temp regularly reaches 90 degrees Hilly or mountainous terrain Frequent trailer towing Uses such as high performance operation It states that, if you do not use your vehicle under any of these conditions, the fluid and filter do not require changing WELL I'LL BE DIPPED IN OIL! I find it amazing that you could go 100K miles without changing the filter and fluid Link to comment Share on other sites More sharing options...
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