Because the fit of the plunger to the body is so close to provide an effective leakdown rate, it is very important that dirt, foreign particles and varnish be prevented from entering the lifter and that a continuous flow of oil is supplied to the lifter as explained in Section 10. In order to accomplish this, it is recommended that every job which is in the shop for valve lifter work be checked for the following conditions.

  1. Check to make sure the oil was changed at the recommended interval.
  2. Check to make sure the oil filter element was changed at the recommended interval.
  3. With the rocker arm cover off, check the condition of the top of the cylinder head to make sure it is not contaminated with foreign particles which could work their way down into the lifter mechanism.
  4. With the engine idling, note whether or not oil is being ejected from the bleed hole in the push rod under the shroud on number 1 and 2 cylinders. In some cases the bleed hole may be on the back side of the push rod so a careful check at this point is required.
  5. Find out if the owner is using heavy duty oil. Varnishes, sludges, and corrosive chemicals have always been more or less a problem in operation of engines. Certain types of operation cause more trouble than others and also some motor oils see m to do a better job and keep engines cleaner than others.

The source of most of this trouble is a combination of compounds developed in the engine due to chemical reactions with the so-called leftovers after the burning of the gas and oil in the cylinder has taken place. The products of combustion naturally get into the engine crankcase. These contain compounds from both the gasoline and the motor oil, and as these compounds circulate in the oil thru the engine oiling system, chemical reactions often take place. The end result of these reactions may be varnish or sludge or highly corrosive compounds, depending on their make-up and the combinations being formed. The operating temperatures of the various parts of the engine and the amount of moisture existing in the engine are also very important factors in determining what the final results will be.

Very noticeable progress has been made in motor oils. It has been found that the addition of certain compounds to motor oils greatly reduces their tendency to oxidize. Also, it has been found that certain other additives will deter and in many cases prevent the formation of the undesirable com­ pounds we are concerned with at this time. The development of these oils was primarily for heavy duty truck operation where conditions were extremely severe and operating and maintenance expenses a major factor. A s more and more of these oils were used, their cost came down until a point was reached where many refineries were supplying these additives in varying quantities to the Premium type oils being sold for passenger car use. Many retail outlets have been using and selling Heavy Duty type oils without knowing it.

Heavy Duty type motor oil does not, as may be generally supposed, indicate a heavy or thick oil. The method or nomenclature used to signify the fluidity or viscosity is the SAE grade designation such as 20-W. Heavy Duty type oil is just as “fluid” as a 20-W Regular or Premium oil. The Heavy Duty designation applies more to the type of car or truck operation and naturally infers that it is more suitable for heavy duty operation, such as high speed driving, long hard trips with a heavily loaded truck or Diesel truck operation with average Diesel fuel.

Our owners’ cars are not subject in general to this so-called heavy duty operation. The connection goes back to the original reason for developing these Heavy Duty type oils; namely to prevent the formation of certain undesirable compounds in an engine. Although Heavy Duty Type oils were originally developed for high s peed, high temperature service it was found that these oils were very desirable to overcome the troubles due to sludge and varnish from other types of operation, such as low speed, low temperature operation. However, the name ” Heavy Duty ” was originally applied to these oils because their first use was in the high speed, high temperature type of service, and the name continued to be applied to the oils regardless of usage .

There are other advantages, however, in using Heavy Duty Oils and the primary one is longer over-all engine life with fewer costly repairs. This is of major importance to our owners. Keep this in mind at all times.

Car manufacturers are not alone responsible for the situation as it exists today. Living with our present condition involves a definite responsibility on the part of the car owner if he wishes a maximum of trouble-free operation. We, as a manufacturer, make recommendations which we feel are sound and justified. It is to the owner’s best interest to follow these recommendations and take certain precautions in his everyday purchase of gasoline and oil.

Heavy Duty type oils are recommended for maxi­ mum protection in all Buick engines. If they are not available, a Premium type may be used. Need­ less to say, those containing detergents, or additives, blended by the refiner or manufacturer are more desirable under the present circumstances than straight run oils.

The use of break-in oils or compounds which are sold separately for the owner or station attendant to add to his crankcase are not recommended. Some of these oils may contain certain materials which may be actually harmful or which may not be compatible with the compounds already added to the oil by the manufacturer.

Use the grade of oil as shown below for the mini­ mum temperature anticipated in your area while that particular oil is in the car.


Not lower than 32°F. – 20W
As low as plus 10°F. – 10W
As low as minus 10°F. – 10W
Below minus 10°F. – 5W if available or 10W plus 10% kerosene

Wherever possible, always use the same brand of oil at all times. The reason for our saying this is that if trouble is encountered the owner will know which oil is causing the trouble. We are also of the opinion that some oils will not be compatible when mixed.

Change the oil filter element at the recommended intervals; namely at time of first oil change, again at first 5,000 mile s and at each 5,000 mile interval thereafter.

The crankcase should be completely drained and refilled with new oil of proper type and grade every 2,000 to 3,000 miles. Adverse driving conditions, such as those encountered in extremely dusty territories or very short run low speed operation in cold weather, call for more frequent changing.

When changing oil, be sure the engine is thoroughly warmed up at time of draining. Draining and refilling a chilled or cold engine could conceivably do no good at all. When an engine is cold, solid material settles to the bottom of the oil pan and oil passages. Even if the oil is drained it is possible to leave a large amount of harmful matter in the engine. Getting the oil hot by running the engine will put the majority of this material in suspension in the oil so that it will be carried out with the oil when it is drained.

If an owner is now using Regular or Premium type oil and wishes to start using a Heavy Duty type oil, we recommend that the first fill of Heavy Duty oil be run a maximum of 500 miles. After this 500 mile run, drain crankcase and oil filter can, install new oil filter element and refill with the oil of your choice.