Buyers Guide
Buying Tips:
Over the past several years, The Star has featured Buyers Guides on nearly all postwar models of Mercedes-Benz classic vehicles. We have discussed the chronology of models within a chassis series – what to look for, current values in different conditions, technical specifications, owners’ experiences, and a variety of pictures to illustrate exterior and interior features. These guides are intended to help members seeking information about a model they are considering. However, they don’t address which model to consider in the first place, what condition to look for, or handling the buying process. This article offers some tips on these topics – based on our own experience.
Purchasing a classic Mercedes-Benz, or any other classic vehicle, is an emotional decision: We don’t really need a classic car to satisfy our transportation requirements. So we suggest you answer the following questions as you contemplate the selection and purchase process to keep this emotional decision as rational as possible.
The answer(s) to this basic question vary, but are usually based upon these responses: A car reminds you of one that you wanted when you were young, one that your parents owned, or that you grew up with; it will attract attention, communicating information about you – your style and taste; you’re attracted to the model’s engineering or styling; or, perhaps you like the tangible connection with history and the past that only owning a classic car can offer.
The list can be long or short, but your answer to this question will affect which model you search for, its age and condition, the intended use, and how much you plan to spend on this investment.
Do you want a sports car, a vintage racer, a four-passenger cabriolet or a coupe, or a practical sedan – and should it be a diesel- or gasoline-powered model? Knowing how you plan to utilize the example will help decide the age, reliability, originality, and condition of a car.
If you’re choosing a vehicle to enter non-competitive car shows or just for fun at community festivals or parades – and for general use – then originality and perfection issues are probably not so important. We definitely advise against buying a car for general use and then opting to restore it to original specifications and showroom condition: This is a recipe for financial disaster because the only way to achieve this is to strip it down to the chassis and restore it to the higher standard.
Many of the models featured in past Buyers Guides – such as the sedans and wagons, and particularly the 1980 diesels – can be used reliably on a regular basis. Although modern cars will always be more reliable, your family can use these classics on a regular basis without being overly concerned with being stranded somewhere or injured in a collision. Moreover, critical parts are readily available for cars that were built in high volumes when new, so they are more easily maintained.
However, buying a car that does need some work can be a good way of spreading repair costs for your classic over several years – and provide you with a satisfying part-time hobby. But there are a few things to consider. First, how skilled are you to do what needs to be done? Second, do you have the space and resources to work continuously on a project? Finally, to what standard do you want the car restored? Unless you’re a well-equipped journeyman mechanic, you’ll be farming out some or most work to professional restorers. Is your budget realistic relative to the value of the car once it’s finished?
The downside to the project-car strategy is that the thrill of the chase – finding and purchasing the car – can blind you to the realities of sustaining a project over the several years required to complete it. Life has a way of impinging upon good intentions. Many projects undertaken with gusto sit in the garage untouched for years after the owner runs into mechanical or personal issues that force postponing the work, eventually being sold for considerably less than the original investment.
For the initial costs, you can consult published and updated price guides that provide market values of the model you are seeking, based on condition. Sources include Hagerty Insurance, Kelley Blue Book, Sports Car Market magazine, and the NADA classic-car appraisal guide.
Condition rankings in these guides typically range from a car in a condition comparable to when it left the factory, suitable for concours competitions; a restoration showing signs of aging that could win at a local or regional car show; a running car that looks good and can be driven safely and reliably; a car that needs some work before it can be driven safely, reliably, and with pride; a car in really rough condition that will need work just to be driven; and finally, a car that can only be used as a source of replacement parts.
Costs in all but the first category can only be determined by paying for a professional estimate – but the assessor needs to be very knowledgeable about the specific model you are seeking. Even when buying from fellow club members, it is possible to be misled by proud owners who cannot see the flaws in their vehicles. Thus, “Caveat emptor!” is the phrase to keep in mind.
If you are seeking a car that will appreciate at or above the rate of inflation, the top-tier Mercedes-Benz marque is a good place to start, and you want a model that was built in low numbers and consequently is rare, is recognized to be sporty and stylish, can be driven on modern highways, and has had a significant owner or other interesting documented history – something called “provenance” in the investment world.
You should certainly ask yourself whether you are buying this car as an investment or to simply enjoy. It is tempting to rationalize the purchase of a classic car in terms of investment value, but this is very rarely the case, except for top-tier classics in perfect condition. On the other hand, if you are looking for a sedan or station wagon because you just love that model, or it is a family heirloom that you want to maintain for personal reasons and pass to the next generation, then you’ll rarely regret your choice.
If you answer these questions honestly and keep them in mind as you sort through the classic-car magazines, attend car shows, and talk to friends about their experiences with their classic cars – Mercedes-Benz or otherwise – you’ll be ready to make a practical and satisfying decision when you finally decide to become a classic-car owner.
The five chassis series of unibody Ponton sedans built 1953-1962 are good choices for the person who wants a true heritage experience in an affordable car that is easy to maintain and makes a good project car for a first restoration. Excellent examples can be found for $15,000 to $20,000. Look for a complete car – accessories can be difficult to find – and expect limited acceleration and top speed that require careful attention at highway speeds. Buyers Guide in The Star, Nov.-Dec. 2013.
The 220SE, 250SE, 280SE and 300SE (W111-W112) coupe and cabriolet sold 1961-1971 are exceptional automobiles that have already moved into the very collectible investment category. The cabriolets, especially the last examples built, are now very pricey, fetching $150,000 or more for the best examples, though good coupes can be found for much less than half that cost. They are comfortable and driveable, but very expensive to restore if they haven’t been carefully maintained or already restored. Buyers Guide in The Star, Sept.-Oct. 2011.
230SL, 250SL, and 280SL (W113) Pagodas, built 1963-1971, have become the most popular collector’s choice for serious first-time classic-car owners. These roadsters, with detachable hard tops, are stylish and desirable, and generally comfortable for daily use, though buzzy at highway speeds. However, high and rising prices (concours restorations can cost more than $100,000, though good examples can be found in presentable condition for less than half that amount) make a careful purchase assessment critical. Buyers Guide in The Star, May-June 2011.
R107 roadsters, including the 350SL, 380SL, 450SL, and 560SL were produced in large numbers for more than 18 years (1971-1989). With the increase in Pagoda prices, the R107 is becoming very popular, though excellent examples can still be found for $15,000 to $20,000. A carefully maintained one-owner car can provide weekend enjoyment or be a good daily driver, but a poorly maintained example can be a very costly investment. Buyers Guide in The Star, Sept.-Oct. 2009.
The 300D turbodiesel sedan (W123) built 1975-1985 and 300TD turbodiesel station wagon (W123) built 1977-1986 have taken on almost cult-like appeal among younger classic owners. Built in large numbers and very long-lived, excellent examples of these vehicles can be found for less than $15,000. These cars can easily be used as economical daily drivers and the capacious passenger compartment has great appeal. Buyers Guide in the Star, Jan.-Feb. 2010.
1. Physical Inspection
Chassis:
Rust in box frame, engine sub-frame, rear suspension frame rails.
Exterior Panels/Trim:
Rust in fender wells, around headlights, floor pans, trunk floors, bottom of doors, doorsills, evidence of body filler on body panels.
Presence and condition of trim pieces, such as side moldings;
these pieces can be difficult to find and are expensive to replace.
Suspension:
Check front suspension for evidence of regular lubrication and ensure that bushings are in good condition.
Wheel bearings (front and rear) adjusted correctly and lubricated
with correct grease.
Tires showing even wear, tread above wear indicators, balanced,
and not more than six years old (check tire date codes).
Engine:
Compression and leak-down tests.
Exhaust smoke (blue, black, white).
Engine mounts in good condition – no excessive engine vibration.
Check for correct finish of valve/cam covers (original finish matte) and other paint/finish details.
Cooling System:
No white stains on engine block (indicates a coolant leak)
Radiator condition, hoses, correct pressure cap and hose clamps
Electrical System:
Wiring harness: check for frayed or missing insulation, presence of corroded or incorrect connectors.
Ignition:
Check distributor, wiring, spark plugs, spark-plug covers and electronic ignition systems.
Fuel System:
Tank (rust, sending unit, mounting straps)
Fuel pump and lines to carburetors (condition) or fuel-injection system (condition).
Brake System:
Master cylinder, wheel cylinders, brake fluid condition, brake hoses to wheels, drums and shoes or rotors, discs, and pads
Interior:
Seats (condition of leather, MB-Tex, cloth), headliner, carpeting and interior lights.
Dash and Instruments:
Condition of dash (leather, vinyl, wood) and operation of all instruments and controls.
Collateral Items:
Owner’s manual(s) and presence of tools and keys of the correct style and quantity for model.
Nice to Have:
Parts and services manuals (original/reproduction), original sales literature.
Complete service records – valuable indication of maintenance, as well as owner’s commitment.
Confirm VIN, Engine Number, ID Plate to ensure body style, engine, and other areas have not been modified (especially conversion of a coupe to a cabriolet).
2. Mechanical & Driving Assessment
Running through the following assessment will help you decide whether to continue purchase discussions. However, a full evaluation by a trained mechanic should always be performed.
Driver’s Seat: Check condition, support, ease of operation.
Mirrors (interior and exterior): Check condition and adjustment.
Engine: Make sure engine fires and operates easily from starting to warm-up, to driving on local streets and highways. When turning off the key, check that engine stops immediately.
Brake Pedal: Check travel and firmness; recheck after 15-30 seconds of continuous pressure.
Clutch Pedal: Check for free play, engagement point, and lack of slippage while accelerating.
Manual Transmission: Operate; check for loose shifting, poor synchromesh, gear noise, bearing noise at idle and when driving.
Automatic Transmission: Should shift smoothly, no odd noises.
Lights: Operate headlights, parking lights, and signal lights (with an assistant to watch the lights around the vehicle).
Dashboard Instruments: Confirm the proper operation of all gauges and warning lights.
Heater, Air Conditioner and Vents: Test for operation and effectiveness; repairs can be costly.
Steering Wheel: Check free play and responsiveness when driving; check that car does not pull to the left or right while driving, or drift to right or left with light grip on steering wheel; if so, check tires for wear patterns indicating wheel alignment, bearings, or bushing problems.
Ride: The car should drive smoothly without any bouncing, steering wheel shimmy or strange vibrations over bumps; shock absorbers should control the car.
Brakes: Check for shuddering when brakes are applied firmly, and that car doesn’t pull to right or left under braking, indicating the need for pads, discs, or replacement of brake hydraulics.
Exhaust: Check for color of exhaust smoke to indicate possible need for engine work or rebuild. Black smoke from gasoline engine indicates mixture is adjusted too rich; blue smoke indicates oil in the exhaust system from worn piston rings if accelerating, or from worn valve guides and seals if decelerating; white smoke indicates water (steam) in the exhaust. Black smoke from diesel engine indicates injection pump timing problem or the need for an engine rebuild.
Smoke From Under the Hood: White indicates a coolant leak; stop the engine immediately. Black smoke from under the hood usually indicates a fire – turn off the engine and call 911 for help immediately. If the smoke continues after engine is turned off, do not attempt to open the hood or you could be burned. If a fire extinguisher is available, direct it at engine from under the car.
Sound Test: When driving, listen for knocking noises from the engine (worn-out engine) under load and acceleration, or pinging with a gasoline engine when accelerating (ignition timing needs adjustment or has old/poor fuel).
Buying Tips:
How to purchase a classic Mercedes-Benz
Article Richard Simonds & Gary Anderson
Images Daimler Archive
Over the past several years, The Star has featured Buyers Guides on nearly all postwar models of Mercedes-Benz classic vehicles. We have discussed the chronology of models within a chassis series – what to look for, current values in different conditions, technical specifications, owners’ experiences, and a variety of pictures to illustrate exterior and interior features. These guides are intended to help members seeking information about a model they are considering. However, they don’t address which model to consider in the first place, what condition to look for, or handling the buying process. This article offers some tips on these topics – based on our own experience.
Purchasing a classic Mercedes-Benz, or any other classic vehicle, is an emotional decision: We don’t really need a classic car to satisfy our transportation requirements. So we suggest you answer the following questions as you contemplate the selection and purchase process to keep this emotional decision as rational as possible.
Why do I want a classic Mercedes-Benz?
The answer(s) to this basic question vary, but are usually based upon these responses: A car reminds you of one that you wanted when you were young, one that your parents owned, or that you grew up with; it will attract attention, communicating information about you – your style and taste; you’re attracted to the model’s engineering or styling; or, perhaps you like the tangible connection with history and the past that only owning a classic car can offer.
The list can be long or short, but your answer to this question will affect which model you search for, its age and condition, the intended use, and how much you plan to spend on this investment.
What will I do with my classic?
Your answer will offer specific criteria to help you determine which example and model-year you desire, as well as its condition. Will its primary use involve car shows and club events, an occasional drive in parades and community events, or cameo appearances for wedding and anniversary celebrations? Perhaps you look forward to weekend excursions or ice-cream runs. Or you may see yourself driving on long-distance road trips to re-create past experiences or share the pleasure of travel with like-minded friends. Or just maybe, you see the classic car as a distinctive daily driver – practical and cost-effective – while identifying you as an individual who bucks the status quo.Do you want a sports car, a vintage racer, a four-passenger cabriolet or a coupe, or a practical sedan – and should it be a diesel- or gasoline-powered model? Knowing how you plan to utilize the example will help decide the age, reliability, originality, and condition of a car.
How original and perfect?
If you are buying a car to enter in competitive car shows and concours des elegance, originality and perfection will be very important. Buying one of these cars isn’t cheap, and the cost to bring a car to these standards can easily exceed the cost of buying one that is nearly correct. Here, the adage “Buy the very best car you can afford,” becomes extremely critical. No matter how close to historic perfection a classic car appears to be, there will always be a hidden problem (even to the seller) that will require your time and money to make perfect.If you’re choosing a vehicle to enter non-competitive car shows or just for fun at community festivals or parades – and for general use – then originality and perfection issues are probably not so important. We definitely advise against buying a car for general use and then opting to restore it to original specifications and showroom condition: This is a recipe for financial disaster because the only way to achieve this is to strip it down to the chassis and restore it to the higher standard.
How important is reliability?
If you want a car for road trips or even as a regular or daily driver, then reliability becomes paramount. Fortunately, Mercedes-Benz cars are known for their reliability and longevity, but the age of the car you choose will make a difference in the kinds of driving you may choose to do. Also, there are after-market changes you can make to any classic car (such as installing an electronic ignition instead of points and condenser, or changing to disc brakes instead of drum) that are fine for driven cars, but will be penalized in concours competitions.Many of the models featured in past Buyers Guides – such as the sedans and wagons, and particularly the 1980 diesels – can be used reliably on a regular basis. Although modern cars will always be more reliable, your family can use these classics on a regular basis without being overly concerned with being stranded somewhere or injured in a collision. Moreover, critical parts are readily available for cars that were built in high volumes when new, so they are more easily maintained.
Do you want to enjoy the car now?
Many people attracted to classic cars for the first time think they can save money by buying a car that “just needs a little loving care.” This belief is generally filled with more fantasy than reality. Clarity about your intentions is critical here. If you want a car to use immediately, then you should buy the best car you can afford – a nice-running car owned by a fellow club member who is the second owner – or even the first – may be available. Still, you should allow some time to verify it is well sorted out and will perform reliably to meet your needs while allowing some funds for maintenance and repairs.However, buying a car that does need some work can be a good way of spreading repair costs for your classic over several years – and provide you with a satisfying part-time hobby. But there are a few things to consider. First, how skilled are you to do what needs to be done? Second, do you have the space and resources to work continuously on a project? Finally, to what standard do you want the car restored? Unless you’re a well-equipped journeyman mechanic, you’ll be farming out some or most work to professional restorers. Is your budget realistic relative to the value of the car once it’s finished?
The downside to the project-car strategy is that the thrill of the chase – finding and purchasing the car – can blind you to the realities of sustaining a project over the several years required to complete it. Life has a way of impinging upon good intentions. Many projects undertaken with gusto sit in the garage untouched for years after the owner runs into mechanical or personal issues that force postponing the work, eventually being sold for considerably less than the original investment.
How much can you afford?
Before making any purchase, work out a realistic budget for how much you are prepared to spend. Remember that your budget will have to cover more than the initial purchase price, including buyer’s premium, taxes, and transportation: There will be the near-term costs to correct any known issues, as well as costs to fix unexpected problems that will inevitably arise. Then there are the running costs of the project work, as well as regular maintenance costs to replace worn parts and keep the car in good running condition.For the initial costs, you can consult published and updated price guides that provide market values of the model you are seeking, based on condition. Sources include Hagerty Insurance, Kelley Blue Book, Sports Car Market magazine, and the NADA classic-car appraisal guide.
Condition rankings in these guides typically range from a car in a condition comparable to when it left the factory, suitable for concours competitions; a restoration showing signs of aging that could win at a local or regional car show; a running car that looks good and can be driven safely and reliably; a car that needs some work before it can be driven safely, reliably, and with pride; a car in really rough condition that will need work just to be driven; and finally, a car that can only be used as a source of replacement parts.
Costs in all but the first category can only be determined by paying for a professional estimate – but the assessor needs to be very knowledgeable about the specific model you are seeking. Even when buying from fellow club members, it is possible to be misled by proud owners who cannot see the flaws in their vehicles. Thus, “Caveat emptor!” is the phrase to keep in mind.
How important is investment potential?
When buying, it is worthwhile to keep in mind that the values for the model you’re seeking will vary over time. Prices for some models have risen rapidly over the past few years and are likely to continue to rise, suggesting that the longer you wait, the more expensive the car is likely to be. On the other hand, the car will be more valuable if you have to sell it unexpectedly. Other cars in the classic category seem to be undervalued, and may offer the opportunity for appreciable increases in value if they’re kept in good condition. Then there is the model that may not yet have stopped depreciating, where increases in value will come slowly – if at all.If you are seeking a car that will appreciate at or above the rate of inflation, the top-tier Mercedes-Benz marque is a good place to start, and you want a model that was built in low numbers and consequently is rare, is recognized to be sporty and stylish, can be driven on modern highways, and has had a significant owner or other interesting documented history – something called “provenance” in the investment world.
You should certainly ask yourself whether you are buying this car as an investment or to simply enjoy. It is tempting to rationalize the purchase of a classic car in terms of investment value, but this is very rarely the case, except for top-tier classics in perfect condition. On the other hand, if you are looking for a sedan or station wagon because you just love that model, or it is a family heirloom that you want to maintain for personal reasons and pass to the next generation, then you’ll rarely regret your choice.
If you answer these questions honestly and keep them in mind as you sort through the classic-car magazines, attend car shows, and talk to friends about their experiences with their classic cars – Mercedes-Benz or otherwise – you’ll be ready to make a practical and satisfying decision when you finally decide to become a classic-car owner.
Heritage: Early Ponton Sedans
The five chassis series of unibody Ponton sedans built 1953-1962 are good choices for the person who wants a true heritage experience in an affordable car that is easy to maintain and makes a good project car for a first restoration. Excellent examples can be found for $15,000 to $20,000. Look for a complete car – accessories can be difficult to find – and expect limited acceleration and top speed that require careful attention at highway speeds. Buyers Guide in The Star, Nov.-Dec. 2013.
Iconic: W111-W112 Coupe and Cabriolet
The 220SE, 250SE, 280SE and 300SE (W111-W112) coupe and cabriolet sold 1961-1971 are exceptional automobiles that have already moved into the very collectible investment category. The cabriolets, especially the last examples built, are now very pricey, fetching $150,000 or more for the best examples, though good coupes can be found for much less than half that cost. They are comfortable and driveable, but very expensive to restore if they haven’t been carefully maintained or already restored. Buyers Guide in The Star, Sept.-Oct. 2011.
Collectible: W113 Pagodas
230SL, 250SL, and 280SL (W113) Pagodas, built 1963-1971, have become the most popular collector’s choice for serious first-time classic-car owners. These roadsters, with detachable hard tops, are stylish and desirable, and generally comfortable for daily use, though buzzy at highway speeds. However, high and rising prices (concours restorations can cost more than $100,000, though good examples can be found in presentable condition for less than half that amount) make a careful purchase assessment critical. Buyers Guide in The Star, May-June 2011.
Affordable: R107 Roadsters
R107 roadsters, including the 350SL, 380SL, 450SL, and 560SL were produced in large numbers for more than 18 years (1971-1989). With the increase in Pagoda prices, the R107 is becoming very popular, though excellent examples can still be found for $15,000 to $20,000. A carefully maintained one-owner car can provide weekend enjoyment or be a good daily driver, but a poorly maintained example can be a very costly investment. Buyers Guide in The Star, Sept.-Oct. 2009.
Practical: W123 300D Sedan and Station Wagon
The 300D turbodiesel sedan (W123) built 1975-1985 and 300TD turbodiesel station wagon (W123) built 1977-1986 have taken on almost cult-like appeal among younger classic owners. Built in large numbers and very long-lived, excellent examples of these vehicles can be found for less than $15,000. These cars can easily be used as economical daily drivers and the capacious passenger compartment has great appeal. Buyers Guide in the Star, Jan.-Feb. 2010.
Pre-Purchase Check Lists
1. Physical Inspection
Chassis:
Rust in box frame, engine sub-frame, rear suspension frame rails.
Exterior Panels/Trim:
Rust in fender wells, around headlights, floor pans, trunk floors, bottom of doors, doorsills, evidence of body filler on body panels.
Presence and condition of trim pieces, such as side moldings;
these pieces can be difficult to find and are expensive to replace.
Suspension:
Check front suspension for evidence of regular lubrication and ensure that bushings are in good condition.
Wheel bearings (front and rear) adjusted correctly and lubricated
with correct grease.
Tires showing even wear, tread above wear indicators, balanced,
and not more than six years old (check tire date codes).
Engine:
Compression and leak-down tests.
Exhaust smoke (blue, black, white).
Engine mounts in good condition – no excessive engine vibration.
Check for correct finish of valve/cam covers (original finish matte) and other paint/finish details.
Cooling System:
No white stains on engine block (indicates a coolant leak)
Radiator condition, hoses, correct pressure cap and hose clamps
Electrical System:
Wiring harness: check for frayed or missing insulation, presence of corroded or incorrect connectors.
Ignition:
Check distributor, wiring, spark plugs, spark-plug covers and electronic ignition systems.
Fuel System:
Tank (rust, sending unit, mounting straps)
Fuel pump and lines to carburetors (condition) or fuel-injection system (condition).
Brake System:
Master cylinder, wheel cylinders, brake fluid condition, brake hoses to wheels, drums and shoes or rotors, discs, and pads
Interior:
Seats (condition of leather, MB-Tex, cloth), headliner, carpeting and interior lights.
Dash and Instruments:
Condition of dash (leather, vinyl, wood) and operation of all instruments and controls.
Collateral Items:
Owner’s manual(s) and presence of tools and keys of the correct style and quantity for model.
Nice to Have:
Parts and services manuals (original/reproduction), original sales literature.
Complete service records – valuable indication of maintenance, as well as owner’s commitment.
Confirm VIN, Engine Number, ID Plate to ensure body style, engine, and other areas have not been modified (especially conversion of a coupe to a cabriolet).
2. Mechanical & Driving Assessment
Running through the following assessment will help you decide whether to continue purchase discussions. However, a full evaluation by a trained mechanic should always be performed.
Driver’s Seat: Check condition, support, ease of operation.
Mirrors (interior and exterior): Check condition and adjustment.
Engine: Make sure engine fires and operates easily from starting to warm-up, to driving on local streets and highways. When turning off the key, check that engine stops immediately.
Brake Pedal: Check travel and firmness; recheck after 15-30 seconds of continuous pressure.
Clutch Pedal: Check for free play, engagement point, and lack of slippage while accelerating.
Manual Transmission: Operate; check for loose shifting, poor synchromesh, gear noise, bearing noise at idle and when driving.
Automatic Transmission: Should shift smoothly, no odd noises.
Lights: Operate headlights, parking lights, and signal lights (with an assistant to watch the lights around the vehicle).
Dashboard Instruments: Confirm the proper operation of all gauges and warning lights.
Heater, Air Conditioner and Vents: Test for operation and effectiveness; repairs can be costly.
Steering Wheel: Check free play and responsiveness when driving; check that car does not pull to the left or right while driving, or drift to right or left with light grip on steering wheel; if so, check tires for wear patterns indicating wheel alignment, bearings, or bushing problems.
Ride: The car should drive smoothly without any bouncing, steering wheel shimmy or strange vibrations over bumps; shock absorbers should control the car.
Brakes: Check for shuddering when brakes are applied firmly, and that car doesn’t pull to right or left under braking, indicating the need for pads, discs, or replacement of brake hydraulics.
Exhaust: Check for color of exhaust smoke to indicate possible need for engine work or rebuild. Black smoke from gasoline engine indicates mixture is adjusted too rich; blue smoke indicates oil in the exhaust system from worn piston rings if accelerating, or from worn valve guides and seals if decelerating; white smoke indicates water (steam) in the exhaust. Black smoke from diesel engine indicates injection pump timing problem or the need for an engine rebuild.
Smoke From Under the Hood: White indicates a coolant leak; stop the engine immediately. Black smoke from under the hood usually indicates a fire – turn off the engine and call 911 for help immediately. If the smoke continues after engine is turned off, do not attempt to open the hood or you could be burned. If a fire extinguisher is available, direct it at engine from under the car.
Sound Test: When driving, listen for knocking noises from the engine (worn-out engine) under load and acceleration, or pinging with a gasoline engine when accelerating (ignition timing needs adjustment or has old/poor fuel).