JFP in PA

My pleasure. Loren originally set up this site to provide both solid technical information, and perhaps more importantly, a place were knowledge could be shared, in order to help all members learn more about their vehicles and systems, so that they as owners could both take care of them and get the most enjoyment from them. It has always been our pleasure and a privilege to help those who wish to gain and apply that knowledge. 😉

Like oil, how fast a coolant breaks down depends upon several factors, including how and where a car is driven, and the condition of the cooling system (existing corrosion levels, etc.) when the fresh coolant was added, so each vehicle can be different. Realistically, most coolants tend to be on a downward curve at about 5-6 years, and a candidate for replacement. But the inherent variability is why you check and test things. Acids attack metals, and tend to attach softer metals like aluminum faster that hard metals like steel; so the presence of a hot, acidic solution running through an alloy engine is not a good thing. Most people also forget that the cooling fins in radiators (and oil to water oil coolers) are thin aluminum, which can quickly corrode through and give you leaks.

We always used distilled water, which we purchased from a local super market for about a buck a gallon. Problem with using tap water is the minerals it contains, everything from sodium to calcium (from the hardness), and even some other metal ions, all of which are bad for the coolant long term, and both lead to corrosion and coolant breakdown. Starting with fresh coolant and distilled water, which is what Porsche always recommended, keeps the system clean and the coolant working longer. There are a lot of really good coolants out there; Porsche's factory stuff is excellent, but even in the aftermarket products like Prestone, Zerex, Peak, and Pentosin are all excellent products, and there are even store brands like NAPA's Long-life all types coolant are also a good choice. Most are silica free, advanced OAT technology products, which are designed for modern alloy engines. Sticking with the factory stuff is usually a very safe bet.

Porsche released a technical bulletin on this code, entitled "Complaint - Red Hybrid Warning Message Appears in the Instrument Cluster: Performing Guided Fault Finding Before Doing Any Other Work (106/19)", which cautions against making decisions on replacing the electric motor for this exact code until "As soon as at least one of the specified fault codes is stored as a passive fault in the fault memory, always perform guided fault finding using the PIWIS Tester before doing any other work in order to avoid incorrect repairs – in particular, replacing the electric motor unnecessarily." I would ask them if they have followed these guidelines before making their determination. Good luck.

Antifreeze is a lot like oil, it has an additive package that controls pH, inhibits corrosion, and lowers the surface tension of the mixture. And like oil, these additive packages break down over time and exposure to heat and metal surfaces, which is why the term "lifetime" antifreeze is a joke. The pH of antifreeze solutions will buffer at a slightly basic pH, over time as the additive's break down, the pH range will shift to slightly acidic, which is not good, particularly in light alloy castings like most modern engines. pH and refractometer freeze points are typically independent of each other, the pH comes from the buffer system in the additive package, the freeze point comes from the glycol concentration. The only time they both move in one the same bad direction is when the pH becomes so acidic that it starts to break down the glycol, the pH drops, and the freeze point rises. This is why we tested for both. A hydrometer is testing for specific gravity, which is exactly what the refractometer is doing as changes in solution densities tends to bend the light in a prism more, which is how you get the reading. Physical chemistry 101....... Check the pH and use the refractometer 😉 And to comment on antifreeze premixes; I prefer to mix my own because I do not know the water quality of the pre mix, and that matters.

On the bottom right side, you can see the zero C line (your unit is calibrated in C, you can also get them in F, which is more convenient): When a drop of pure water is placed on the prism, the blue line would be at the 32 F degree line, meaning the test fluid will freeze at that temp. A 50/50 mix of distilled water and antifreeze would put the blue line around -50 to -60F. Note you have two antifreeze scales, one for ethylene glycol, the other for propylene glycol based coolants, so you need to know which type you are using to get the correct scale value. This is the PDF manual for the Robinair 75240 model I own, which tells you how to calibrate and use the unit: https://www.robinair.com/sites/default/files/75240.pdf I've had mine for literally decades, and it does the job every time.

Get a coolant refractometer, uses one drop of fluid and is deadly accurate. Amazon sells them for around $20 or so, and you can get pH test strips for a few bucks for a jar holding 20-30 that also only need one drop. You don't always need zillion dollar tools to do the job correctly. 😉

We would also visually inspect several things, like the brakes for thin pads, worn rotors, etc.; freeze point pH and clarity of the coolant; moisture level in the brake fluid, wiper blade condition and washer fluid level, oil level and condition, any fluid leakage (oil, coolant, power steering, brakes), abnormal tire tread wear and tread depth, exterior light functions (do they all work), and signs of physical damage like dents or rust on the lines under the car or the exhaust system. All this takes just a few moments to do, but can prevent the owners from getting stranded or stopped because a brake light is out.

If you had any pronounced vacuum leaks, your air/fuel ratios would go haywire, and eventually your computer would reach the end of its enrichment capability, both of which would trigger codes.

Your photo happens to be the exact digital manometer I use, bought off of Amazon for about $35-40 at the time. Only one tube needs to be connected the the vacuum source, the other functions as an atmospheric pressure reference that you are measuring the vacuum level against. I also used a Porsche oil fill cap, but did it a bit more elegant than the one in your photo; I purchased brass barbed bulkhead fittings of Amazon and use O-rings on each side to seal it. As every car out there has an oil fill cap, you can make up as many vehicle specific testers as you need. To test, you need to first make sure the vehicle is thoroughly warmed up, testing it just after a 15 to 20 min. drive is optimal. The reason for this is you will get some erratic data if the engine is not warm in in normal running condition. The test sequence is simple and quick: Connect the manometer to the engine and turn the manometer on; set the units scale to inches of water, zero it if it has that capability, then start the car and let it run for about 1 min. to let the manometer stabilize, take your reading. Yes, Jake did develop a "better mousetrap" AOS, but it never saw the light of day, and not for reasons of cost, or because it did not work. If memory serves, Jake discovered that third part emission's hardware manufacturers are required to submit their devices for independent testing, at their own cost. The testing takes a lot of time, and is expensive as Hell, and once you passed you had to get very expensive liability protection for it as you could be held responsible for damaging the environment, and fined millions of $ if it failed. Net result was that it did not make any sense from an economic stand point as you would need to sell them for a lot of money in hope of recovering your sunk costs before you died of old age. Sometimes, the laws designed to protect the environment totally suffocates innovation …. 😬

Glad you got it sorted 👍

Welcome to RennTech Couple of possibles: (1) A wiring issue causing the heaters to malfunction. (2) The reflash itself. A lot of people have experienced all sorts of weird DME issues after getting aftermarket reflashes done as these systems are quite often set up to try to eek out small power gains by trying to trick the basic DME engine control functions, everything from strange codes to blocking connection to the OBD II port. Returning the vehicle to the factory DME flash put an end to the problems.

As each line on the oil level gauge is a small fraction of a liter (somewhere around 0.2 L), by adding a two quart (or liter) sump extension, and then lowering the level two bars from the full line, you have still increased your total oil capacity by around 1.6 L; and as any increase in oil capacity is generally a good thing, you are still ahead of the game. 😉

Not even remotely correct in this world. But I would agree that Porsche's A40 spec is irrelevant as it is a marketing tool, not a lubricant specification. If you want real specs, consider products that meet or exceed ACEA A3/B3/B4, which are real, technically based and widely accepted performance standards.

A "breather" is simply and atmospheric vent, not unlike an open window. The vacuum signal "throttling" done by the AOS is much like the thermostat in your home: It keeps the environment in the sump at a controlled level. If there were no vacuum level, the low tension rings would not seal, pressure would build up, and engine oil seals would blow out. Too high a vacuum signal and the intake starts inhaling oil as Jake showed in his video and the engine kills itself. The AOS vacuum throttling function keeps the sump "just right". 😉 That part in the diagram marked "breather" is actually how the sump vents any pressure that might build up after the engine is shut down and there is no vacuum. The pressure would wend its way around the system and back into the intake manifold, and back out into the world. It all has to go somewhere; the engine cannot function as a sealed vessel.

On the track, it is not uncommon to see one of these engines blow some oil smoke. Sometimes this may only happen in certain corners, and not in others. Problem stems from too much oil being retained in the upper engine area (read cam covers), where it cannot drain down fast enough through the M96's oil scavenging system, and the AOS becomes overwhelmed. This is one of the reasons Porsche developed the X51 package, which uses a "northwest passage" extra scavenging system to get the oil back down where it belongs. One trick a lot of track rats learn is to drop the oil level in the sump a couple of bars to help control the oil level in the heads. On the street, we always filled customer's sumps to at least two bars below the max line for this exact reason. We also tested everyone of the cars that passed through the shop for sump vacuum levels, as the AOS deteriorates and then fails a lot more often than people expect. It should be considered a maintence consumable item that needs to be replaced before it begins to fail. One comment on your diagram: The actual intake vacuum signal at idle can be as high as 26-28 inches of mercury, and one inch of Hg is 13.6 inches of water. The only time the intake would drop to anywhere near the levels in your diagram would be a wide open throttle. So the AOS is not only separating oil and returning it to the sump, it is throttling the intake vacuum down to around 5 inches of water in the sump to help the low tension rings seal.

Welcome to RennTech Normally, oil films on the inside of the intake system is a sign the AOS is on its way out.

A lot of people and shops simply update the cars to the later setup, which is totally bolt in, or update to aftermarket bars and mounts that are adjustable for better handling.

That is not going to be easy, most people use a torch to heat the aluminum section where the tapered pin inserts, then wack it out with a hammer when the aluminum is hot. Unfortunately, that often snaps off the tapered pin or destroys the bar link itself, which is the reason it is common to see 74-77 911's with no rear sway bars.

That ball and socket end link is a press in item: Porsche stopped using this design in 1977 because it is such a pain to seal with and move to a more "wrench friendly" mounting system in 1978, which is a simple bolt in swap for your car.

You CAN Bus system is how various systems communicate with each other. Sometimes the individual modules lose contact and need to be reset to work properly, which again requires a Porsche specific diagnostic tool. While there are are some aftermarket diagnostic tools that can "see" a fault, like yours they typically cannot communicate and reset the system. This is the unfortunate state of automotive diagnostics, the OEM's are required by law to allow some systems to be accessed by third party diagnostics tools, but many component's are "walled off" and require very specific tools to work with them, in a vain attempt to secure work for their dealer network. Law also requires the OEM to make their factory diagnostic systems available to the aftermarket; in Porsche's case, their PIWIS system is only available for lease, with the first year costing around $20,000.

That is because you need to have access to a Porsche specific scan tool like the PIWIS Porsche factory tool; a "global" European scan tool won't be able to access this system, and won't see anything wrong. Some independents have this tool, all dealers have them.

As that engine is a VW variant, a VW shop with the VagCom should also be able to clear it.

I do not believe that the Durametric software supports this function, but you can check with them directly on that. You may need to have a dealer do a code clear with the PIWIS.

Reductant Consumption is the Diesel Exhaust Fluid (DEF) that is used to assist in converting leftover exhaust particles to harmless gases. Are you sure your DEF tank isn't empty?