Tech Tips:
                                                                                                                             03/03/06

WATCH FOR FLOOD VEHICLES!
I've seen a number of warnings in the auto industry press warning of vehicles from the Gulf area who are flood damaged showing up all over the country. There is a goverment agency crushing some of them, but there are more out there showing up in salvage auctions and resale auctions. There is also an incomplete list of VIN  numbers of flood salvage vehicles available at www.nicb.org. These vehicles are very hazardous; not only because of water and mud damage affecting the operating systems of the cars, but the flood waters were highly contaminated with both toxic materials and bacteria. There is a reported case of a Mississippi firefighter dying from blood poisoning (sepsis) from a small cut he got removing an accident victim from a car. Watch for cars with moisture or mud in odd places that would not normally get wet in the average rainstorm. You can get more information by searching "flood cars" and "hurricane zone vehicles."
 

LOW MILEAGE AIN'T A GOOD THING!
Often somebody tells me that they got a really good deal on an older car with really low mileage, or that they have a car they don't drive much because they don't want to put too much mileage on it. The problem with this is that cars are made to be driven, and a low-mileage car is not a bargain in the real world. A customer told me once that they had gotten good money for VW they had recently sold because of its low mileage. What they didn't tell the buyer was that the reason the mileage was so low was that it usually came home with a hook in its mouth; the only thing that was worn on the car was the back bumper because it got pushed so often. In other words, an exceptionally low-mileage car is usually either a lemon or a garage queen. Not moving is harder on a car than driving it; when a car sits, stuff rots and/or corrodes, gasoline turns into a smelly, sticky and nonflammable substance, rubber turns into either tar or Bakelite, rings rust onto the cylinder walls and into their grooves, etc., etc. If you are taking a car out of storage, don't just hook up a battery and try to start it. You need to pull the spark plugs and pour oil down the cylinders and let it soak for a few days, and then wiggle the front pulley or fan (if it is a solid fan) gently to avoid broken rings and scratched cylinders; drain the fuel system, clean the tank and lines with fuel system cleaner, check as much as you can that things that are supposed to move actually can move freely. If you are going to store a car, drain the fuel, slosh some heavy oil around it the tank, pour some oil down the cylinders and cover up everywhere you can that air might get into the engine. Of course, don't leave it with the weight on the tires, and do store it inside somewhere, covered.

Additional notes from our shop checklist:
     We don't start any car without checking oil and coolant. If the car hasn't run for about six months or more, we make sure the fuel system is clean, the cooling system is clean and filled properly, and the brakes work. Drain coolant, if any, make sure radiator is clean, replace radiator hoses, flush engine water passages, check for leaks, make sure water pump turns freely and quietly, replace with correct coolant (read labels on container, especially with aluminum heads or engines). Pull wheels, check tires, brakes and wheel bearings. Calipers and wheel cylinders should move freely and be clean and dry. If caliper or wheel cylinder pistons resist retracting, crack the bleeder screw and try again; if this frees them, you probably have brake hoses or lines that are clogged inside. Sometimes brake hoses can look OK externally (no obvious cracks or stickiness) but have come delaminated on the inside and act like one-way valves for brake fluid. (Note: see Brake Fluid )   The fluid in the master cylinder is probably gone or deteriorated; if there is any question about it, rebuild or replace the cylinder. When bleeding the system, bleed the master cylinder first,  cracking the output lines if it doesn't have a bleeder; no point to pushing air or bad fluid through the system. If the fluid in the reservoir or any cylinders is black or has black specks, you have a seal problem. Light rust can be removed from discs and drums with fine sandpaper, badly rusted or scored drums or rotors should be replaced. Drums and rotors can only be turned .060" or less, and this is the depth of a medium scratch. Check suspension for perished bushings, sloppy tie rod ends and bearings. Check electrical connections (especially at the fuse box and the back of the starter solenoid, and the battery ground to engine and body) for corrosion or deterioration. (See Electrics ) In general, assume that everything has rotted or gotten contaminated, and apply your intelligence to the project.
 

Mercedes-Benz V8 engines (450, 380, 420, 500,560) are very picky about oil pressure. This is one engine that you do NOT want to get low on oil! Two of the uglier things that can happen is for the timing chain tensioner to go slack, the chain flops around, the little plastic chain guides break up, and really bad things happen from there. The other thing is that the cam can go dry. The cams are lubricated by a "cam oiler" system that squirts oil onto the cam lobes through a tube with little nozzles. The early cars have an 8mm tube, which makes it even more critical than the later 10mm setup. You do not want these nozzles to sludge up! We have seen fried cams, rocker arms flung through the valve cover, bent valves, and other ugly things.
One tip from the pros--when you change oil, fill the filter canister as best you can, and then before you actually start it up, disconnect the coil wire and crank it for a short time to bring up the oil pressure before you fire it.
 
 
 

See our expanded GASKET AND SEAL TIPS
New: QUICK TIPS
New: HELP! IT WON'T RUN!
 DIESEL TIPS
 COOLING SYSTEM TIPS.
 ELECTRICAL NOTES
STRANGE LIQUIDS
  Everybody knows about the three main fluids that go in a car: gas, oil, water. Do you know about all the others?

Don't stop looking when you find a probable cause for a problem.  There is no rule that you can't have more than one problem at a time, just like you can have measles and chickenpox at the same time. Whenever someone tells me that "I've already done this, and this,and this, so it HAS to be this", my answer is that there is no such thing as "has to be this". It can always be something else. You'd think that a car is a straightforward mechanical/electrical object, but it is amazing how weird they can be. Almost as weird as people.
 
 
 

We plan to add to this page often; if you have a question about the operation of a car, or about an import marque in general, submit by e-mail to importautosbdo@juno.com. If it looks like it would be of interest to others, we'll discuss it here.
 

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LEGAL STUFF:
All information here is offered as suggestions only; the final decision as to any car repair is that of the installer and/or the owner of the vehicle. This information is the result of our own best research and experience, but we make no guarantees or warranties of any kind as to its applicability to any specific situation.