1999Porsche911

Again, this misses the point entirely. Lifting the car by the engine is not a root cause of mount failure. If a mount bursts during a lift, it was because the mount was already beyond its useful life and was going to fail regardless of if the car was lifted by the engine, or not. It was a "dead mount walking" and was going to fail, that is just the facts. If a mount bursts during a lift, be glad it failed when it had your attention, rather than out on the road somewhere, where you would not know that it failed. It may not be the "root cause" but it puts unnecessary pressure on the mount which stretches the boot. This weakens the mount. Even if it doesn't break, it increases the possibility of the mount not aborbing vibration as well as it is designed to do. For someone who often stresses that Porsche knows best, note that jacking the car up using the engine as support is specifically not recommended by Porsche and is a ludacris way to test whether the mounts may be leaking or otherwise failing. The mount is designed for hanging and is not designed for compression. I know I will not change your mind, but hopefully others reading this post will be able to make an informed decision.

Sounds like your coolant temps are as the engine was designed. Your problem is nothing more complex than a lack of airflow when driving slowly. The only way you can reduce the temperature is to increase airflow. Do my fan mod and you'll be running much cooler. http://www.renntech.org/forums/index.php?s...&hl=fan+mod

So, is your reasoning to lift the car using the mounts for support to justify buying new mounts? Why would you want to hasten the failure of what you describe as an already weak mount when there are alternate, safer methods to lifting the back of the car?

On the right side of the engine just above and between cylinders 5 and 6.

The reduction in phosphorous in motor oil will hasten the death of engines going forward. Most people are not aware of the importance of zinc/phosphorus in protecting their engine. Its purpose is to produce a chemical reaction with metal surfaces to form a film and prevents metal to metal contact. An example of components that are better protected is the cams and tappets. The pressure between the cam and tappet can reach more than 150,000 psi. Without a film with less shear strength than the component’s metal, it does not take long to wear the components out. The reason they are reducing the phosphorus level in oil is to prevent damage to the catalytic converters and sensors. If you don’t burn any oil like any good engine, phosphorus is not a concern. If you burn oil, then it can affect you cats. So, you can use oil with the proper levels of ZDDP and possibly shorted the life of your cats or use the new formulation and definitely shorten the life of your engine. Not a difficult choice for most people. The ZDDP in your oil begins working by coating the metal at pressure points immediately upon engine start. Other than a newly built engine (which should use a cam/tappet lube anyway), there is always a film between components and changing your oil frequently will not change this fact. Your oil also gets thicker over time as it suspends the dirt and acids from you engine and becomes less efficient at lubricating and cooling. Whether it is better to change your oil every 3,000 miles or 10,000 miles is debatable, but keeping your oil longer does not improve the benefits of anti-wear compounds. For those who feared that Mobil 0W40 was not protecting their engines properly to begin with, the new formulation is even more reason to avoid it like the plague.

my indy told me that mobil 1 reduced the zinc and whatever compounds like u said. so he uses lubrimoly (sp?) 0w-40 on my car. he says it's much better quality given the recent change in formula at mobil 1. again, what i am saying above has just as much conjecture contained within as whatever statements you have made in the past, present and future. lol There are many things you can do to increase the antiwear additives. Many use a can of cam/lifter pre lube with every oil change. You can use a good diesel oil or racing oil and many manufacturers sell high mileage oils. All these oils can be mixed with other oils. The coating of metals in the engine with the zinc is as important, if not more, than the viscosity of the oil.

Your hot coolant temperatures, as proven by normal temps while on the highway, are caused by insufficient airflow. Water Wetter will do nothing to correct that.

Many of the oil formulations have replaced or reduced the zinc and phosphorus antiwear componds. This will do more damage to your engine than the industry is admitting to. However, there are many oils, including some Mobil 1 oils, that have higher antiwear agents and should be used when possible. Diesel oil is a good choice as is select "high mileage" oils. At minimum, if you use an oil with low antiwear compounds, add 3+ quarts fo either diesel or other oil having high levels of zinc and phosphorus.

The sensor is installed in a grommet between the first 2 intake tubes on the top of the engine on the passenger side. There is a 2 cnductor cable connected to the back sensor. If this wire is disconnected, the fan will operate, even when the car is off and temperature is above a specific limit. It will also show up as a fault by a flashing temp light. Check the connection.

The switch in my fan mod is not to correct a non functioning fan system or relay. Fixing the relay fault is quite simple and should be done with new relays when necessary. The fan mod is to turn on the HIGH speed fans at will and at any temperature. Or you can eliminate the switch altogether and have the high speed fans come on below a certain engine speed, vehicle speed, etc.

So your mechanic said there was NO refrigerant in the system AND said there were no leaks? Did he think that someone deliberately hooked up a vacuum to the system and sucked it all out? You have a leak. You need to find the leak AND a new mechanic before recharging again.

Pull the ABS control fuse and see if idle smooths out.

Possible bad $30 ignition switch. A search will tell you about it.

The normal and targeted temperature of your engine is 195F. Your engine will and should never run at 180F. If you do a search, you'll find lots of info on coolant temperature. Your slow speed fans will not kick on unless the AC is on or the coolant temperature reaches slightly more than 200F. High speed fans will not kick on until you are above 215F or you have excess pressure in the AC system. Your engine will not run at 195F except under optimal conditions, including proper airflow through the radiators. During slow driving, you will likely see 215F+ coolant temps. Do not rely on the idiot gauge to display accurate coolant temperature. A search will also show you how to test the fan relays.

Some advice here. Be careful of the VERTICAL waterline that is behind the air intake- it is very easy to break! There are also two small black hard plastic lines going to a sensor towards the top drivers side of the engine- BE CAREFUL TO NOT BREAK THOSE. I have no idea what they are for but broke them and replacement was such a ***** that I just devised a much more simple solution. GOOD LUCK! It seems that the small black hard plastic lines had broken again after the repair and some driving. There are two of them that attached to some sensor and go into the engine bay. Mine broke into so many pieces and disappeared into the darkness of the engine bay! My question is, where do they connect to inside? I've been through the parts catalogue and can't come up with any answers. If some one could point out to me which diagram to look at, that would be great. I would want to buy the plastic lines and replce them if I knew where they connected on the other side. Any help would be great! Thanks. If the black tubes you are speaking about come from the electric changeover valve behind the alternator, one comes from the reserve vacuum tank under the left intake to the straight nipple on the valve. The other comes from the resonance flap on the back intake crossover tube to the nipple on the side of the valve. Tube from vaccum reserve should have vacuum at all times. The flap tube, if vacuum is applied, should close the flap which can be heard if you suck on the line. I did some seaching on the Forum and found this thread. http://www.renntech.org/forums/index.php?showtopic=25688 . I think this might be it. Is there a source for the hard tubes? There doesn't seem to be any part number to this tubing. Do you think it would be a difficult fix to replace them? You mentioned it is to the iside intake area. Looks like a tight squeeze. If I have tackled the filler tube replacement, do you think I could tackle replacing the vacuum lines? Thanks in advance! That is the valve I am referring to. Valve part number 996 605 123 01 and the black hard tubes are 000 043 205 01 and come in various lengths. Any tube of similar diameter can be used and be found at an auto parts store.

Totally agree. There is so much myth around this subject. But the fact is that the oil change intervals set by manufacturers are the longest they think they can get away with. The reason is that they pay environmental levies based partly on the resources consumed by a car during its service life. Fewer mandated oil changes means lower levies. They are managing this cost against the risk of warranty claims, whereas an owner just wants his car to last. I would suggest a more protective oil is more important than the frequency of the changes. Mobil 0W40 simply does not have the film strength of many other oils. All engines have loosness and some degree of balance problems. Unless you have the proper film strength in the oil between the moving parts, the constant pounding will eventually create too much heat and occasional contact of the componants. Compound the loosness with constant changes in torque, an inferior oil will eventually lead to problems. Nothing personal here... But complete unfounded BS, you just don't know when to stop do you? It's been documented by Porsche that 15w is NOT a recommended oil weight for the M96. Many Porsche dealers and many more indy shops use 0w-40 and for good reason. It's what Porsche engineers put time and energy and $ to deliver. Who are you to recommend 15w on Porsche forums thereby exposing unsuspecting newbies to your vitriol? The more you push 15w, the more mental you become. What's highly convenient is you have not the $ or time or skills top back your 15w cheerleading hubris on my M96, Loren's M96, phillip's M96, Nancy's M96. All you got is your keyboard and a broadband connection just like the rest of us. :) Did I mention 15W oil? BTW, since you like using other people's names to drive home your point, some of those people you mentioned use 15W50.

Totally agree. There is so much myth around this subject. But the fact is that the oil change intervals set by manufacturers are the longest they think they can get away with. The reason is that they pay environmental levies based partly on the resources consumed by a car during its service life. Fewer mandated oil changes means lower levies. They are managing this cost against the risk of warranty claims, whereas an owner just wants his car to last. I would suggest a more protective oil is more important than the frequency of the changes. Mobil 0W40 simply does not have the film strength of many other oils. All engines have loosness and some degree of balance problems. Unless you have the proper film strength in the oil between the moving parts, the constant pounding will eventually create too much heat and occasional contact of the componants. Compound the loosness with constant changes in torque, an inferior oil will eventually lead to problems.

Some advice here. Be careful of the VERTICAL waterline that is behind the air intake- it is very easy to break! There are also two small black hard plastic lines going to a sensor towards the top drivers side of the engine- BE CAREFUL TO NOT BREAK THOSE. I have no idea what they are for but broke them and replacement was such a ***** that I just devised a much more simple solution. GOOD LUCK! It seems that the small black hard plastic lines had broken again after the repair and some driving. There are two of them that attached to some sensor and go into the engine bay. Mine broke into so many pieces and disappeared into the darkness of the engine bay! My question is, where do they connect to inside? I've been through the parts catalogue and can't come up with any answers. If some one could point out to me which diagram to look at, that would be great. I would want to buy the plastic lines and replce them if I knew where they connected on the other side. Any help would be great! Thanks. If the black tubes you are speaking about come from the electric changeover valve behind the alternator, one comes from the reserve vacuum tank under the left intake to the straight nipple on the valve. The other comes from the resonance flap on the back intake crossover tube to the nipple on the side of the valve. Tube from vaccum reserve should have vacuum at all times. The flap tube, if vacuum is applied, should close the flap which can be heard if you suck on the line.

Get the car to operating temperature and if the the plug is disconnected from the sensor, the fan should be running. It should tunr off when you reconnect it. Relay is behind the driver's seat under the shelf carpet in the silver relay carrier. Or you can ground the relay (#8) to test if fan motor is functional.

Seems to me, the cheapest way to attempt to reduce or eliminate your burning is to fill the crankcase with Mobil Extended Performance 15W50 and drive the car hard. I would also recommend (whether you change the oil or not) to bring the car up to redline and let the engine brake it back down to. Repeat this a few times and do it periodically to keep cylinder walls clean and smooth. This can drastically reduce oil burning when oil is getting past the rings. well what about breaking in a new new re-man engine.... they fill it with 0W40..... take it to red line on the first day? I've heard for performance its good and also seats the rings properly... 1999Porsche911... what do you think about this technique? I would remove the 0W40 and put in 15W50. I would then warm it up and test the rev limiter several time to make sure it worked properly. Engine breaking is as good, if not better for seating rings. can I use mobil 1 5W50 instead? or is there a distinct advantage in going with 15W50 when breaking in a new motor? 15W50 Extended Performance has more phosphorus and zinc than 5W50 and keeps things cleaner. 5W50 is fine though.

Seems to me, the cheapest way to attempt to reduce or eliminate your burning is to fill the crankcase with Mobil Extended Performance 15W50 and drive the car hard. I would also recommend (whether you change the oil or not) to bring the car up to redline and let the engine brake it back down to. Repeat this a few times and do it periodically to keep cylinder walls clean and smooth. This can drastically reduce oil burning when oil is getting past the rings. well what about breaking in a new new re-man engine.... they fill it with 0W40..... take it to red line on the first day? I've heard for performance its good and also seats the rings properly... 1999Porsche911... what do you think about this technique? I would remove the 0W40 and put in 15W50. I would then warm it up and test the rev limiter several time to make sure it worked properly. Engine breaking is as good, if not better for seating rings.

Seems to me, the cheapest way to attempt to reduce or eliminate your burning is to fill the crankcase with Mobil Extended Performance 15W50 and drive the car hard. I would also recommend (whether you change the oil or not) to bring the car up to redline and let the engine brake it back down to. Repeat this a few times and do it periodically to keep cylinder walls clean and smooth. This can drastically reduce oil burning when oil is getting past the rings.

there seems to be this popular notion, a follow the leader mentality that an engine that does not burn oil is somehow better than an engine that does when in fact the only downside with the latter is the annoyance factor in topping off oil however frequently you need to do it. more greater the frequency the more annoying it gets. so long as it's within porsche's allowance, i wouldn't be afraid of the engine... with that said.... porsche's allowance requires a lot of annoying time spent topping off plus expense. my S54 M3 engine burned oil. it dynoed higher than any stock S54 at the dyno day here back several years ago. my f20c honda engine burned oil. same dyno results relative to others. i followed the break-in guidelines to a tee. so me making the claim that an engine that does burn moderate amounts of oil means greater relative power output... it's just as absurd of a claim/notion that it's somehow better, more desireable to have an engine that does burn oil. good luck with your "issue". not many porsches that i've read about burn as much oil as yours. it seems excessive. but again the answer is not running oil weights/brands not on porsche's recommended list. It's NOT just the "annoyance" of having to add oil. Your CAT's can be destroyed prematurely, carbon buldup in intake, valves, etc, reduction in octane rating of fuel, fouling of plugs, etc, etc. Not to mention the increased pollution in causes. At Porsche's worse "acceptable" level of oil burning, it can also add almost $0.25 for every gallon of gas you burn. If the cause of the oil burning is due to ring failure, then Porsche is not providing you the compression in the engine they promised. You are also deluting the oil with gasoline, which is never good. The fact is, everything else being equal, the performance of an engine that burns no oil will outperform one that does.

Normal at operating temperature.

thanks for the response guys! JeTexas, im thinking those mods are adding more air in the car and its overly compensating with oil and fuel? i'am also getting less mpg than originally when i had the cars w/o modifications. im not complaining about mpg though, more oil consumption than anything else. any feel for your 996 oil consumption over a 1000 mile period anyone? Zero, nada, zippo oil usage, ever. But, then again, I only use Mobil 0W40 for keeping the door hinges from squeaking. Move to the Mobil 15W50 I suggested above as it has better cleaning agents than any of the other Mobil synthetics. I have yet to see an engine that burns oil using Mobil 0W40 that did not substantially reduce or eliminate oil burning. Please don't start this oil debate again - you have voiced your opinion many times on this. Thank you. If it continues I will close this thread. I don't see a debate, but guidance. If you don't want people responding to other's questions, I suggest you block them from doing so. I will continue to respond to people's questions when I have the opinions/answers. If you do not want me too, you are welcome to ban me from this forum.