Hey RickZ28 and rigby5, good points you said both... But I have to step in:
"...Coolant NEVER wears out, and old is always much less corrosive than new..."
The information I have, tells me a very different story: Having formulated several coolant concoctions years ago when we did research on engine emissions and reformulated fuels development, I must say the opposite is true. "Modern" engine cooling systems from 25 years ago to today, have a very unfavorable combination of materials, all of them for mainly cost vs performance considerations. Cast Iron engine blocks are still good enough, but engine heads are now almost always done in aluminum. Add different bronzes, brass, Zinc and even more alloys to the recipe and you have a very good electrochemistry class teaching material!!! A good coolant formulation has up to 11 different compounds, but frequently commercialy available ones drop a few of them in order to "save" (their maker's money, that is!)
Seriously, inside the cooling system there are SEVERAL corrosion mechanisms going on simultaneously, you have: Galvanic action, Oxygen attack, Erosion, Cavitation damage and the most aggresive and ignored one: Electrolysis damage when by chance, the aluminum component is not properly grounded, so that an errant current destroys the component fast and furiously! (check the web for this). Even rubber hoses deteriorate by electrical phenomena.
The better approach to properly maintain a cooling system is: 1) Test for electrolysis with a simple multimeter test; correct ANY bad grounds IMMEDIATELY! 2) Do perform TIMELY coolant flushes and replacements: every year for "old" (mostly green-yellow types), and after 3 to 4 years with the newer "HOAT" (Organic Acids types) IMPORTANT: once the factory charge is replaced, the new batch WON'T last another 4 years (even when it is labeled "5-Year")... the reason is that now the system is partly corroded and will be releasing more and more metallic ions into the new coolant. What we SAW, was that HOAT only may lastas much as 5 years the first time. 3) Keep the system Air tight: any radiator or recovery tank loose hose that lets air in, will facilitate Oxygen attack. 4) Try NOT to use plain tap water, distilled is best, but demineralized is enough. We have seen some "ready to use" coolant mixtures that came contaminated from factory! I prefer to get concentrated coolant and demineralized water.
"Once the collant has stabilized, leave it alone"
As soon as the coolant touches the inside of the engine and radiator, it starts to wear, because it has a FINITE quantity of corrosion inhibitors, that have to react chemically to combat the corrosion mechanisms. Nobody can put an excess of inhibitors to create an "ethernal" coolant, it causes other problems. We have seen terror cases (a couple of the dreaded "DEXCOOL" (Death-cool) examples. I personally use MOPAR "5-Year, 100,000 mile" in my vehicles with better results that average, but can't recommend it unconditionally: companies have the nasty habit of getting worse products every year.
To sum it up if you really want to keep your car more than 5 years or so, maintain the coolant properly. If you operate a Fleet or large diesel trailer, investigate a heavy duty filtering and inhibitor adding system. Diesels even have a tougher problem: Cylinder liner damage, for which they need extra measures. Amclaussen.
i have been wondering about these long disassembly procedures and if engineers in automotive are instructed to design things this way. I have to take the taillight assembly off of my motorcycle to replace the batter in middle of the bike. A tab on one panel is carefully interlocked with a hole on another panel to insure it is a pain in the a_ _ to do anything on this bike.
Once I started thinking about it, the dealers are only getting a few hundred dollars over invoice when they sell a car and I cannot imagine paying a staff of sales people, cashier, cleaning people, car wash/prep people for only a few hundred bucks per car.
Is the whole plan actually based on service calls that eventually come into the dealer after the sale. A diabolical negotiation plan between dealer and manufacturer to insure cars are sold at competitive prices and good dealers with good service programs get repeat (service) business from the customers that buy cars at that dealer.
Designs this "bad" don't happen on their own and I can't imagine even a monkey could randomly do this to almost every vehicle on the market. Come on, I have to take the right front wheel off and several pieces of plastic engine shrowd to change my oil filter!
What a GRRREAT IDEA !!! It came to my mind putting an extra belt zip-tied to the engine when replacing the timing belt in my car, since it is a hassle to disassemble the right engine mount just to be able to replace the belt (the belt goes around the engine mount). Amclaussen. But, thinking more on this, in newer cars the timing belt drives the water pump, and by the time the belt is ready for replacement, the pump bearings are ready to go; and in interference engines, a failing water pump can trigger belt failure by tooth breakage. Catastrophic engine failure follows.
Anyway, "modern" engines require A LOT of component removal just to have access to the water pump: Air conditioner compressor and mounting plate, alternator removal, some pulleys, all kinds of belt covers... etc. AND the room is non-existant! Lets shout HOORAY to the great Monkey designers of today... Go ahead and keep playing with AutoCad as madly as you played Nintendo! (I'm shure that letting the kids become automotive "designers" and asking them to be fast with AutoCad, but NOT requiring them to be able to dissasemble and reassemble an engine, is the main cause of our present day woes).
HMMM, I could agree with you creamysbrianna... but it depends on which model of VW. Latter designs of their higher price vehicles, like the Passat, are full of badly done design in respect to serviceability and component layout. But (VERY FORTUNATELY for DIY people like me), they decided a year ago to revive an OLDER, discontinued design: now they are selling the OLDER Jetta generation IV together with the latest generation VI, and calling it most appropriately "Clasico" (the Classic), intended to be perceived as that old standard of simplicity: the VW Bug.
In this revival, you can do most of the maintenance and most repair at home. The 2.0L engine intake manifold appears to block the sparkplugs, but looking closely, those are slightly canted, oil filter requires a "cap style" filter wrench, but otherwise it is a snap. All hoses and belts are user replaceable, as is fuel filter and air filter; so I expect it will be almost a pleasure to work on, and IT WAS my first consideration when I decided which car to buy. With few accesories like a simple and straightforward air conditioner, manual 5 speed gearbox, no ABS... What could go wrong? Amclaussen.
I couldn't agree more with Rigby5! Let me give a good example of the entirely flawed thinking, characteristic of the electronics-for everything Monkeys of the top level:
(it is related to the alleged "advantage" of "multiplexing" the commands to open and close the power door locks on some Dodge vehicles on only two wires):
..."There are 2 resistors in the switch, a 620 ohm for unlock, 2700 ohm for lock and the switch is open at rest. The switch toggles 12 volts between the 2 resistors.
The return wire goes the BCM (Body Control Module) to be interpreted as to what selected position the switch is in. From there the BCM will power the door lock motors in the door latches to lock or unlock the doors. So basically the switch is '2 states plus off' (power in, difference out). By multiplexing commands on 1 wire, they probably saved 20-30 feet of wire per car on power door locks alone! This saves money, electrical complexity and weight."
OH YEEEAH! Now the damn thing decides to act erratically in thousands of cars and vans, and the factory says it is NOT a common failure, and is tipically NOT covered by warranty, so you end up investigating it and finding there are at least TWO companies here in Mexico City that cater to it; to the tune of 3 to 6 hundreds of dollars in order to "fix" the Body Control Modules"
Now the good part: the Damn-Damn-Damn Module is located (you guess what) under the leftmost part of the dash, buried DEEP inside it, with the steering column leaving no room to work, it is so hard to remove the #%& module, that those gentlemans ask YOU to remove it and carry it to their place, so they can "fix" the faulty circuitry!
I simply cannot see how 20 or so feet of wire can be LESS expensive than a large module which sole enclosure costs more than those few feet of thin wire.
Curiously enough, 12VDC into 2,700 Ohm gives 0.0444 A and into 620 Ohms gives 0.1935 A... And of course, everybody will recognize that old golden industrial standard: the good old 4 to 20 milliamps for a control signal. Amclaussen.
this is all about pain threshold and tolerance. Nobody likes fixing a popped bicycle tube on the side of the road; but its always doable. I had a '76 honda civic, a take apart tonka toy. A toyota p/u truck, a pleasure to work on and do valve adjustments. A VW bug; change the engine like a battery. Now I had a Ford probe turbo, Wouldn't fix anything under the hood but marveled at the front wheel over-torque. BMW 325 tight little car but electronics were expensive and service mystery. GMC yukon, like my chrysler magnum 360 ci. hog. But dash comes off as easy as the grill. Now my VW TDI Touareg. A man (or woman)'s got to know his limitations.I'm sorry but I don't understand why anybody'd own a car that you can't see all the plugs and battery if its got 'em. And you expect to service it yourself.
I have a 2002 Saab 9-5 with100K miles on it. The heater blend door broke. This door moves to block air from the heater core when you turn on the A/C, so we were getting hot air all the time. To fix it, we would have had to replace the whole heater assembly which was $3K, and disassemble to entire dash, and console. We end up installing a valve (and hose) in the water line near the firewall which lets the water bypasses the heater core. The valve has a little switch that was run to the dash that turns it on/off. Works great!. The hardest part was finding a valve that fit.
Bradley Miller - Your heater core replacement story describes the same hassel for my 1995 Cougar. Same story here, green/yellow liquid on the floor mat and fogging on the inside of the windshield, I knew the heater core had sprung a leak. Normally I would have replaced the core myself, having replaced one some time ago on my first car, a 1955 Chevy! Thinking the Cougar repair should be fairly easy, after all, I'd done this once before, I began by examining the under hood rat's nest of wires and hoses, and also figured there was no way for my 65 year old body to contort upside down to get under the dashboard, I took the 'EASY' way out. I took the car to a reputable local mechanic. He had experience with this model car before and knew the first step was to "DROP THE DASHBOARD", (which includes moving the steering wheel out of the way) . He replaced the heater core with a $75 dollar one, Performed a complete cooling system drain, cleaning, and refill, and it only came to just under $700 bucks! all labor charge except about $125 for parts and material. It's getting so thet leasing a car and trading in every 3 years may be cheaper in the long run than paying for expensive repairs after the warrenty expires.
Bob from Maine, your lucky to get by with just 6 hours to replace the blower motor in your Mercedes. 1980,when I was still working Automotive, I was thumbing through our foreign auto flat rate book and ran across the flat rate time for replacing the heater core on a 1980 Mercedes 450SL. It required 28 HOURS!!Including pulling the engine and tranny, stripping the front interior, seats, carpet and dash assy. At our shop, we always added 30% more time on foreign autos, just to CYA. Apparently the heater core was the first part on the assembly line then everything else was built around it!
But at least this time the dreaded "Law of Unintended Consequences" worked in the opposite way: the uncommon battery location has the happy consequence of keeping the battery a little fresher compared to higher underhood temperatures. My 2002 Dodge Stratus R/T Turbo Sedan needed it's FIRST EVER battery replacement at 8 (eight) full years of mostly daily driving...
Sometimes the designers fail in your favor!!!
[FYI Factory battery ("MOPAR") was made by Johnson, and is a sealed group 75 std duty battery]
Today, after two more replacement batteries, I have developed some dexterity in changing them at home (like 95% of all maintenance and repair on this car), but I really have learned to fear underhood repairs to this car, concluding that I have to plan ahead and assign approximately FOUR TIMES the usual repair time compared to my much older 1991 Spirit R/T, which has much less tight spots! (so much for progress!). Amclaussen.
Festo's BionicKangaroo combines pneumatic and electrical drive technology, plus very precise controls and condition monitoring. Like a real kangaroo, the BionicKangaroo robot harvests the kinetic energy of each takeoff and immediately uses it to power the next jump.
Design News and Digi-Key presents: Creating & Testing Your First RTOS Application Using MQX, a crash course that will look at defining a project, selecting a target processor, blocking code, defining tasks, completing code, and debugging.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.