Arriving the same week at our shop was another victim of bad maintenance: a Nissan Pathfinder with a noisy timing chain. Timing chains normally last a very long time but this one was cut down in its prime (only 190,000 kilometers) by a lack of oil changes. Upon removing the access holes to the cam gears it became immediately evident why this chain had failed at a young age. Inside the cover there was a thick layer of baked on sludge: something that occurs only from infrequent oil changes.
Several thousand dollars later a new timing chain, guides & tensioner were installed and a thorough cleaning process removed the sludge. Just to be safe we did a double oil change after the repairs to ensure that any loose particles of sludge were removed. Fortunately after repairs were done the engine sounded fabulous though it is difficult to say whether any other components will fail early due to the neglect this engine suffered.
Bottom line: change you oil regularly as it will save you lots of money in the long run.
As further food for thought: this vehicle was recently purchased used so the new owner was footing the bill for the previous owner’s neglect. This illustrates the importance of shopping wisely for a used car. Have a mechanic inspect it and be sure to obtain the owner’s maintenance records. If the maintenance records are unavailable or clearly show neglect then you would be wise to find a better vehicle.