Are good project managers also good project leaders?

Not necessarily. 

Not compulsory. Management & leadership are varrying qualities. Leaders are influencers derived their power from their own expertise, skills, knowledge etc. Whereas Managers derived their authority due to their legitimate position in a company. Good Project Manager may be a good leader but not always.

YES, WITHOUT LRADERSHIP QUALIYY, CANNOT BE A GOOD MANAGER

sure--good managers must be good  leaders

This question is becomng intriguing. There are cases that Project Manager lacks the ability to lead, to influence his Team to do the right thing according to what he thinks. Sometimes, these create a clash between Project Managers in a Team aside from being a multi-cultural teamwork to being a faction-centered organization, thereby limiting the performance of the project. This can be controlled by a Project Manager that has the ablity to lead his Team towards commom project objectives.

Not necessary, since the attributes of a manager (more of a delegator) and a leader (more of a person who leads by example) are distinct

Answer is very Simple Once you have any Project means you have all the tolls ,Plans Now as a good Leader you have to choose a good team and then it is totaly up to you how you assign and split the Jobs to an individual by analysing his / her Leadership skill cuzz i believe that every human have the leadership Skill but  with different abilities to lead people. Now as a leader it is your job to identify Leaders with their Skills and speciality, If you chosse right Leader & People for right job for  the accepted project would be like a Black forest cake to celebrate once you get the project complete perfectly :) 

What qualities are most important for a project manager to be an effective project leader? It's a question often asked and one that makes us sit back and think. Over the past few years, the people at ESI International, a leader in project management training, have looked at what makes an effective project leader. They quizzed some highly-talented project leaders and compiled a running tally of their responses. Below are the top 10 qualities in rank order, according to their frequency listed.

Inspires A Shared Vision

An effective project leader is often described as having a vision of where to go and the ability to articulate it. Visionaries thrive on change and being able to draw new boundaries. It was once said that a leader is someone who "lifts us up, gives us a reason for being and gives the vision and spirit to change." Visionary leaders enable people to feel they have a real stake in the project. They empower people to experience the vision on their own. According to Bennis "They offer people opportunities to create their own vision, to explore what the vision will mean to their jobs and lives, and to envision their future as part of the vision for the organization." (Bennis, 1997)

Related Article: Which of These Leadership Traits Do You Demonstrate?

A Good Communicator

The ability to communicate with people at all levels is almost always named as the second most important skill by project managers and team members. Project leadership calls for clear communication about goals, responsibility, performance, expectations and feedback.

There is a great deal of value placed on openness and directness. The project leader is also the team's link to the larger organization. The leader must have the ability to effectively negotiate and use persuasion when necessary to ensure the success of the team and project. Through effective communication, project leaders support individual and team achievements by creating explicit guidelines for accomplishing results and for the career advancement of team members.

Integrity

One of the most important things a project leader must remember is that his or her actions, and not words, set the modus operandi for the team. Good leadership demands commitment to, and demonstration of, ethical practices. Creating standards for ethical behavior for oneself and living by these standards, as well as rewarding those who exemplify these practices, are responsibilities of project leaders. Leadership motivated by self-interest does not serve the well being of the team. Leadership based on integrity represents nothing less than a set of values others share, behavior consistent with values and dedication to honesty with self and team members. In other words the leader "walks the talk" and in the process earns trust.

Enthusiasm

Plain and simple, we don't like leaders who are negative - they bring us down. We want leaders with enthusiasm, with a bounce in their step, with a can-do attitude. We want to believe that we are part of an invigorating journey - we want to feel alive. We tend to follow people with a can-do attitude, not those who give us 200 reasons why something can't be done. Enthusiastic leaders are committed to their goals and express this commitment through optimism. Leadership emerges as someone expresses such confident commitment to a project that others want to share his or her optimistic expectations. Enthusiasm is contagious and effective leaders know it.

Empathy

What is the difference between empathy and sympathy? Although the words are similar, they are, in fact, mutually exclusive. According to Norman Paul, in sympathy the subject is principally absorbed in his or her own feelings as they are projected into the object and has little concern for the reality and validity of the object's special experience. Empathy, on the other hand, presupposes the existence of the object as a separate individual, entitled to his or her own feelings, ideas and emotional history (Paul, 1970). As one student so eloquently put it, "It's nice when a project leader acknowledges that we all have a life outside of work."

Competence

Simply put, to enlist in another's cause, we must believe that that person knows what he or she is doing. Leadership competence does not however necessarily refer to the project leader's technical abilities in the core technology of the business. As project management continues to be recognized as a field in and of itself, project leaders will be chosen based on their ability to successfully lead others rather than on technical expertise, as in the past. Having a winning track record is the surest way to be considered competent. Expertise in leadership skills is another dimension in competence. The ability to challenge, inspire, enable, model and encourage must be demonstrated if leaders are to be seen as capable and competent.

Ability To Delegate Tasks

Trust is an essential element in the relationship of a project leader and his or her team. You demonstrate your trust in others through your actions - how much you check and control their work, how much you delegate and how much you allow people to participate. Individuals who are unable to trust other people often fail as leaders and forever remain little more that micro-managers, or end up doing all of the work themselves. As one project management student put it, "A good leader is a little lazy." An interesting perspective!

Cool Under Pressure

In a perfect world, projects would be delivered on time, under budget and with no major problems or obstacles to overcome. But we don't live in a perfect world - projects have problems. A leader with a hardy attitude will take these problems in stride. When leaders encounter a stressful event, they consider it interesting, they feel they can influence the outcome and they see it as an opportunity. "Out of the uncertainty and chaos of change, leaders rise up and articulate a new image of the future that pulls the project together." (Bennis 1997) And remember - never let them see you sweat.

Team-Building Skills

A team builder can best be defined as a strong person who provides the substance that holds the team together in common purpose toward the right objective. In order for a team to progress from a group of strangers to a single cohesive unit, the leader must understand the process and dynamics required for this transformation. He or she must also know the appropriate leadership style to use during each stage of team development. The leader must also have an understanding of the different team players styles and how to capitalize on each at the proper time, for the problem at hand.

Problem Solving Skills

Although an effective leader is said to share problem-solving responsibilities with the team, we expect our project leaders to have excellent problem-solving skills themselves. They have a "fresh, creative response to here-and-now opportunities," and not much concern with how others have performed them. (Kouzes 1987)